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Publication Number: FHWA-HRT-04-042
Date: July 2004

Guidelines for Ultrasonic Inspection of Hanger Pins

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Figures

Figure 1.  Model of an elastic material.  Diagram.  This figure is a diagram model of an elastic material showing a grid-like system of discrete masses connected by elastic springs to adjacent masses.  The masses appear as a system of gridded dots, where each dot is connected to the adjacent dot by a zigzag line, which represents an elastic spring.

Figure 2.  Longitudinal wave.  Diagram.  This figure is a diagram representation of a longitudinal wave as it moves through a two-dimensional slice of material.  The diagram appears as a grid of dots, 14 in the vertical direction and 49 in the horizontal direction.  The dots are all evenly spaced in the vertical direction.  Horizontally, the space between adjacent dots increases progressively to a maximum distance and then decreases progressively.  This series of progressively increasing and decreasing spaced dots is repeated several times in the horizontal direction.

Figure 3.  Shear wave.  Diagram.  This figure is a diagram representation of a shear wave that moves at right angles to a longitudinal wave.  The diagram shows a series of dots, evenly spaced in all directions from adjacent dots.  Dimension is depicted by a mass of evenly spaced dots, 14 deep and occurring between two parallel zigzag lines.

Figure 4.  Basic principle of pulse-echo technique.  Diagram.  This figure is a simple line drawing that represents the pulse-echo ultrasonic testing technique as it passes through a piece of material.  The left side of the diagram illustrates a housing containing a transmitter and a receiver below it.  An ultrasonic signal is depicted as an arrow originating at the transmitter and entering a piece of test material.  The wave passes through the material and out to a back wall, which reflects the signal back through the material and to the receiver.  The diagram also illustrates the path of the wave in defected test material.  When the ultrasonic wave hits a defect or discontinuity, it is reflected back to the receiver, rather than passing through the material to the back wall.

Figure 5.  Sketch of a typical ultrasonic A-scan.  Diagram.  This figure is a sketch of a typical A-scan, which is the amplified signal from the receiver of the pulse-echo testing apparatus.  The horizontal axis represents transit time of the signal, and the vertical axis corresponds to the amplitude of the echo signal.  The sketch illustrates a fairly stable baseline and a sharp spike, representing the transmitter pulse, near the start of the signal travel time.  About one-third of the way across the baseline is a smaller spike, representing the reflected echo from a defect in the test material.  Near the end of the chart is another spike, representing the echo from the back wall.  This peak is midway in amplitude between the transmitter pulse and the defect.

Figure 6.  Influence of distance on reflected ultrasonic signal.  Diagram.  This figure consists of two simple line drawings that illustrate the effect of distance on the amplitude of the wave signal.  The top drawing is a sketch of an A-scan and the bottom drawing illustrates the pulse-echo wave traveling from the transmitter through the test material to the back wall.  The test material is shown with two equivalent defects at different locations.  The A-scan shows, from left to right, the relative amplitudes of the near-field noise signal, the signal from the first defect, the signal from the second defect, and the signal from the back wall.  The amplitudes of the signals from the two equivalent defects at different locations in the test material are not equal.  The sketch of the A-scan illustrates that the signal from the defect further from the transmitter is lower in amplitude than the signal from an equivalent defect located closer to the transmitter.

Figure 7.  Influence of shadow effects on ultrasonic signal.  Diagram.  This figure consists of two simple line drawings that illustrate the shadow effect on the amplitude of the ultrasonic wave signal.  The top drawing is a sketch of an A-scan and the bottom drawing illustrates the pulse-echo wave traveling from the transmitter through the test material to the back wall.  The test material is shown with two defects of two sizes.  The A-scan shows, from left to right, the relative amplitudes of the near-field noise signal, the signal from the larger defect, the complete absence of a signal from the smaller defect, and the signal from the back wall.  As illustrated by the sketch of the A-scan, presence of the larger defect completely masks the signal from the smaller defect.

Figure 8.  Influence of defect orientation on ultrasonic signal.  Diagram.  This figure consists of two simple line drawings that illustrate the effect of defect orientation on the amplitude of the ultrasonic wave signal.  The top drawing is a sketch of an A-scan, and the bottom drawing illustrates the pulse-echo wave traveling from the transmitter through the test material to the back wall.  The test material is shown with a defect orientated with its long side parallel to the path of the wave.  The A-scan shows, from left to right, the relative amplitudes of the near-field noise signal, the absence of a signal from the defect, and the signal from the back wall.  As illustrated by the sketch, the horizontal orientation of the defect results in an insufficient surface to produce a meaningful reflection and wave signal.

Figure 9.  Influence of defect size on ultrasonic signal.  Diagram.  This figure consists of two simple line drawings that illustrate the effect of defect size on the amplitude of the ultrasonic wave signal.  The top drawing is a sketch of an A-scan, and the bottom drawing illustrates the pulse-echo wave traveling from the transmitter through the test material to the back wall.  The test material is shown with two different sized defects in similar locations.  The A-scan shows, from left to right, the relative amplitudes of the near-field noise signal, the signal from the smaller defect, the signal from the larger defect, and the signal from the back wall.  The larger defect reflects more ultrasonic energy, resulting in a signal with a greater amplitude.

Figure 10.  Schematic of direct pitch-catch technique.  Diagram.  This figure is a simple line drawing that represents the direct pitch-catch technique as an ultrasonic wave passes through a piece of material with and without a defect.  The left side of the diagram illustrates the path of the wave through a piece of material with no defects.  The transmitter is located along the bottom of the test material, and the receiver is placed in the area where the reflected beam is expected, given no defects in the test material.  The wave travels from the transmitter up to the edge of the test material where it is reflected back down to the receiver.  The right side of the diagram shows the path of the wave through material with a defect.  The transmitter is located along the bottom of the test material, and the receiver is placed in the area where the reflected beam is expected, given no defects in the test material.  The path of the ultrasonic wave is from the transmitter to the edge of the test material, where it is reflected down to the location of a defect, and to the receiver.

Figure 11.  Schematic of indirect pitch-catch technique.  Diagram.  This figure is a simple line drawing that represents the indirect pitch-catch technique as an ultrasonic wave passes through a piece of material with and without a defect.  The left side of the diagram illustrates the path of the wave through a piece of material with no defects.  The transmitter is located along the bottom of the test material, and the receiver is placed in the area where the reflected beam is expected, given a defect in the test material.  The wave travels from the transmitter up to the edge of the test material where it is reflected back down to the receiver.  The right side of the diagram shows the path of the wave through material with a defect.  The transmitter is located along the bottom of the test material, and the receiver is placed in the area where the reflected beam is expected, given a defect in the material.  The path of the ultrasonic wave is from the transmitter to location of the defect, where it is reflected down to the receiver.

Figure 12.  Piezoelectric effect.  Diagrams.  This figure consists of four simple diagrams, each illustrating an example of the piezoelectric effect.  A crystal face is represented by rectangle.  Figures 12A and 12B illustrate the direct piezoelectric effect where an applied stress induces electric charges on each face of a crystal.  Figure 12A represents the effect of tensile strength.  Pressure is represented by arrows that point away from the face of the crystal.  Positive charges occur at the top face of the crystal, and negative charges are at the bottom face of the crystal.  Figure 12B represents the effect of compressive stress.  Pressure is represented by arrows that point toward the face of the crystal.  Negative charges are shown at the top face of the crystal, and positive charges are at the bottom face of the crystal.  Figures 12C and 12D illustrate the converse piezoelectric effect where an applied electric field induces a mechanical deformation.  Figure 12C illustrates the effect of application of an electric field to a crystal.  The electric field is represented by an arrow from the bottom of the crystal face to the top, resulting in a compressed shape, which is narrower but greater in height than the original.  Figure 12D shows the effect of reversing the application of electric field.  The electric field is represented by an arrow from the top of the crystal face to the bottom, resulting in a compressed shape, which is wider but shorter in height than the original.

Figure 13.  Schematic of a straight beam piezoelectric ultrasonic probe.  Diagram.  This figure is a cross-sectional line drawing, which illustrates the components and configuration of a basic straight compression beam probe.  It shows a square box with an opening at the top for the lead wires.  The outer layer of the box represents a housing.  Within the housing is a damping block, with an inclined surface.  The damping block is located above the transducer, which is contained within a cover.  The lead wires attach to the damping block.

Figure 14.  Schematic of an angle beam piezoelectric ultrasonic probe.  Diagram.  This figure is a cross-sectional line drawing, which illustrates the components and configuration of the angle-beam probe.  It shows the components of the straight beam probe described in figure 13, supplemented with an acrylic wedge or shoe.  The wedge is a right-angle trapezoid covered with absorbent material on the top and its perpendicular side.  The probe is located on the slope of the Perspex wedge.

Figure 15.  Concept for generating distance amplitude correction curves.  Diagrams.  This figure consists of two simple line drawings that conceptually illustrate how a DAC curve would be generated for an angle beam transducer.  Figure 15A shows the transducer and hole location for generating a DAC curve.  A rectangular test block is shown with a side-drilled hole.  Four different scanning patterns can be used, depending on the transducer location.  The transducer can be in position D or the upper left of the block; position A or the upper right of the block; position C, the bottom left of the block; or position D, the bottom right of the block.  Figure 15B illustrates the generation of a DAC curve from the scan signals.  The first signal represents the transmission peak, followed by progressively decreasing amplitude signals from probe locations A, B, C, and D.  Connecting the peaks of these signals generates the 100-percent DAC curve.

Figure 16.  Typical pin/hanger assembly.  Diagrams.  This figure consists of two simple line drawings that represent the typical pin/hanger assembly shown in (A) elevation and in (B) cross section.  Figure 16A identifies the concrete deck at the top, the suspended web, and the hanger plate attached to the suspended web by the nut and pin.  Figure 16B is a cross section of the hanger plate, nut, and pin assembly.  It shows the suspended span web, and an enlarged view of the nut, pin, and hanger plate.

Figure 17.  Application of a straight beam transducer.  Diagram.   This figure is a simple line drawing of a cross section of the hanger/pin assembly, similar to that shown in figure 16B, but additionally illustrating the application of a straight beam transducer.  It shows the suspended span web between the hanger plates; an enlarged view of the nut and pin assembly; and critical defect locations on the pin.  A straight beam transducer is shown attached to the left side of the pin.  Also illustrated are the beam centerline and the beam spread as it passes through the pin.

Figure 18.  Application of an angle beam transducer.  Diagram.   This figure is a simple line drawing of a cross section of the pin/hanger assembly, similar to that shown in figure 16B, but additionally illustrating the application of an angle beam transducer.  It shows the suspended span web between the hanger plates; an enlarged view of the nut and pin assembly; and critical defect locations on the pin.  An angle beam transducer is shown attached to the left side of the pin.  Also illustrated are the angled beam centerline and the beam spread as it passes through the pin.

Figure 19.  Typical physical measurements.  Diagram.  This figure is a simple line drawing of a cross section of the pin/hanger assembly and associated physical measurements.  The figure identifies the suspended span web, hanger plate, nut, and pin assembly.  Potential shear planes are shown on either side of the suspended span webs where they meet the pin.  The following measurements are identified on the drawing: length of the pin is uppercase L; the distances from the face of the pin to the face of the web are uppercase F uppercase W subscript 1 and uppercase F uppercase W subscript 2; the measured thickness of the web is lowercase T subscript W; the measured gap width between each hanger plate and the suspended span web is lowercase T subscript lowercase G1 and lowercase T subscript lowercase G2; the distances from the face of the pin to the face of the hanger on each side are uppercase F uppercase H subscript 1 and uppercase F uppercase H subscript 2; the distance from the face of the pin to either potential shear plane is uppercase D; and the measured thickness of the hangers are lowercase T subscript uppercase H1 and lowercase T subscript uppercase H2.

Figure 20.  Sample ultrasonic test data.  Data Page.  The figure is a page of ultrasonic test data, which combine basic information and measurements with geometry of the connection assembly.  The data sheet is shown to illustrate a sample form that could be used in the collection of test data.  Basic data that are identified on the form are bridge designation, location of the assembly being tested, date of inspection, pin location; reference plane; stick-out (inches); face of hanger (inches); face of web (inches); web thickness (inches); UT length (inches); distance to shear plane (inches); the nominal pin dimensions (inches), including threaded diameter, barrel diameter, barrel length, and total pin length; nominal hanger dimensions (inches), including width and thickness; nominal web dimensions (inches), including thickness; UT scan angle (degrees); indication level (decibels); reading radial location (hours, minutes); radial location 1 (hours, minutes); radial location 2 (hours, minutes); distance to index (inches); sound path distance (inches), and radial distance (inches).  The geometric data for the connection assembly, shown on elevation and cross section diagrams, includes physical measurements, calculated location of shear planes, and basic design information.

Figure 21.  SDHTB details.  Diagram.  Companion to figure 22.  This figure is a simple line drawing illustrating the side-drilled-hole test block and its dimensions.  The test block is 305 millimeters (12 inches) square and 51 millimeters (2 inches) thick.  The hole is 6 millimeters (0.25 inches) in diameter, and is located 229 millimeters (9 inches) from the top and 178 millimeters (7 inches) from the left side of the block. 

Figure 22.  Photograph of the SDHTB.  Color Photograph.  Companion to figure 21.  The figure is a color photograph of the test block described in figure 21.  The photograph shows the hole as well as the thickness of the block.

Figure 23.  Typical pin geometry.  Diagram.  This figure is a simple line drawing of the pin and its dimensions.  A longitudinal or elevation view and a cross section of the pin are shown.  The pin illustrated is 225 millimeters (8.875 inches) in total length and 76 millimeters (3 inches) in diameter.  The diameter of the pin ends is 57 millimeters (2.25 inches).  The pin ends extend 44 millimeters (1.75) inches out from the main body of the pin.  The flange between the pin ends and the main body of the pin is 3 millimeters (0.125 inches) thick.

Figure 24.  Pin 1 defect details.  Diagram.  This figure is a simple line drawing of pin 1 showing its dimensions, and size and location of the crack in longitudinal or elevation view and in cross section.  Pin 1 is shown as 225 millimeters (8.875 inches) in length.  Flaw 1 is located 97 millimeters (3.8125 inches) from end 1 (left side of drawing).  On the cross-sectional view, the defect is shown at 220 degrees, and is approximately 3 millimeters (0.125 inches) by 6 millimeters (0.25 inches) in size.

Figure 25.  Pin 2 defect details.  Diagram.  This figure is a simple line drawing of pin 2 showing its dimensions, and size and location of the cracks in longitudinal or elevation view and in cross section.  Pin 2 is shown as 225 millimeters (8.875 inches) in length.  Flaw 1 is located 94 millimeters (3.6875 inches) from end 1 (left side of drawing).  Flaw 2 is located 75 millimeters (2.9375 inches) from end 2 (right side of drawing).  On the cross-sectional view, flaw 1 is shown at 50 degrees, and is approximately 6 millimeters (0.25 inches) by 13 millimeters (0.5 inches) in size.  Flaw 2 is shown at 160 degrees, and is approximately 6 millimeters (0.25 inches) by 13 millimeters (0.5 inches) in size.

Figure 26.  Pin 3 defect details.  Diagram.  This figure is a simple line drawing of pin 3 showing its dimensions, and size and location of the cracks in longitudinal or elevation view and in cross section.  Pin 3 is shown as 225 millimeters (8.875 inches) in length.  Flaw 1 is located 94 millimeters (3.6875 inches) from end 1 (left side of drawing).  Flaw 2 is located 75 millimeters (2.9375 inches) from end 2 (right side of drawing).  On the cross-sectional view, flaw 1 is shown at 150 degrees, and is approximately 25 millimeters (1 inch) by 13 millimeters (0.5 inches) in size.  Flaw 2 is shown at 330 degrees, and is approximately 25 millimeters (1 inch) by 13 millimeters (0.5 inches) in size.

Figure 27.  Pin 4 defect details.  Diagram.  This figure is a simple line drawing of pin 4 showing its dimensions, and size and location of the crack in longitudinal or elevation view and in cross section.  Pin 4 is shown as 225 millimeters (8.875 inches) in length.  Flaw 1 is located 94 millimeters (3.6875 inches) from end 1 (left side of drawing).  On the cross-sectional view, flaw 1 is shown at 35 degrees, and is approximately 19 millimeters (0.75 inches) by 19 millimeters (0.75 inches) in size.

Figure 28.  Pin 5 defect details.  Diagram.  This figure is a simple line drawing of pin 5 showing its dimensions, and size and location of the crack in longitudinal or elevation view and in cross section.  Pin 5 is shown as 225 millimeters (8.875 inches) in length.  Flaw 1 is located 94 millimeters (3.6875 inches) from end 1 (left side of drawing).  On the cross-sectional view, flaw 1 is shown at 180 degrees, and is approximately 25 millimeters (1 inch) by 25 millimeters (1 inch) in size.

Figure 29.  Pin/hanger mockup details.  Diagram.  This figure consists of three simple line drawings that show the top, side, and end views of a pin/hanger connection mockup.  The dimensions of the pin are similar to other pins in the study.  As shown in the top view, the overall length of the pin is 225 millimeters (8.875 inches).  Each pin end extends 44 millimeters (1.75 inches) out from the main pin body.  The side view illustrates the three plates, one perpendicular to the top load platen and two perpendicular to the bottom load platen, which respectively represent the suspended span web and two hanger plates found in a typical connection.  Two load platens, each 25.4 millimeters (1 inch) thick and 225 millimeters (8.875 inches) long, are shown 30 millimeters (1.1875 inches) above and below the pin assembly.  The end view shows the outer diameter of the pin as 76 millimeters (3 inches), the diameter of the pin ends as 57 millimeters (2.25 inches), and the width of the two load platens as 127 millimeters (5 inches).

Figure 30.  Beam diffraction results for 8-degree, 5-megahertz, 12.7-millimeter diameter transducer.  Charts.  The figure consists of four charts that present results of the experimental beam diffraction tests obtained with the 8-degree, 5-megahertz, 12.7-millimeter-diameter transducer for four different penetration depths.  The X-axis on all four figures is distance in millimeters (negative 60 to positive 60) from maximum indication.  The Y-axis on all figures is the relative indication intensity in percent.  The first figure (30A) presents the results for a 76.2-millimeter penetration, and shows a best-fit Gaussian distribution or bell curve between approximately negative 15 and positive 15 millimeters, at an indication intensity of about 78 percent.  Figure 30B presents the results for a 127-millimeter penetration, and shows the bell curve between approximately negative 25 and positive 25 millimeters, at an indication intensity of about 80 percent. The results for a 177.8-millimeter penetration, at an indication intensity of 80 percent, are shown in figure 30C as a bell curve between approximately negative 35 and positive 35 millimeters.  Figure 30D presents the results for a 228.6-millimeter penetration, and shows a best-fit Gaussian distribution between approximately negative 40 and positive 40 millimeters, at an indication intensity of about 75 percent.  Overall this series of charts illustrates that, as the depth of penetration increases, the breadth of the beam diffraction also increases.

Figure 31.  Beam diffraction results for 0-degree, 5-megahertz, 12.7-millimeter diameter transducer.  Charts.  The figure consists of four charts that present results of the experimental beam diffraction tests obtained with the 0-degree, 5-megahertz, 12.7-millimeter-diameter transducer for four different penetration depths.  The X-axis on all four figures is distance in millimeters (negative 60 to positive 60) from maximum indication.  The Y-axis on all figures is the relative indication intensity in percent.  The first figure (31A) presents the results for a 76.2-millimeter penetration, and shows a best-fit Gaussian distribution or bell curve between approximately negative 10 and positive 10 millimeters, at an indication intensity of about 80 percent.  Figure 31B presents the results for a 127-millimeter penetration, and shows the bell curve between approximately negative 15 and positive 15 millimeters, at an indication intensity of 80 percent.  The results for a 177.8-millimeter penetration, at an indication intensity of about 82 percent, are shown in figure 31C as a bell curve between approximately negative 20 and positive 20 millimeters.  Figure 31D presents the results for a 228.6-millimeter penetration, and shows a best-fit Gaussian distribution between approximately negative 30 and positive 30 millimeters, at an indication intensity of about 82 percent.  Overall this series of charts illustrates that, as the depth of penetration increases, the breadth of the beam diffraction also increases.

Figure 32.  Beam diffraction results for 0-degree, 2.25-megahertz, 25.4-millimeter diameter transducer.  Charts.  The figure consists of four charts that present results of the experimental beam diffraction tests obtained with the 0-degree, 2.25-megahertz, 25.4-millimeter-diameter transducer for four different penetration depths.  The X-axis on all four figures is distance in millimeters (negative 60 to positive 60) from maximum indication.  The Y-axis on all figures is the relative indication intensity in percent.  The first figure (32A) presents the results for a 76.2-millimeter penetration, and shows a best-fit Gaussian distribution or bell curve between approximately negative 12 and positive 12 millimeters, at an indication intensity of 80 percent.  Figure 32B presents the results for a 127-millimeter penetration, and shows the bell curve between approximately negative 30 and positive 30 millimeters, at an indication intensity of 75 percent. The results for a 177.8-millimeter penetration, at an indication intensity of 75 percent, are shown in figure 32C as a bell curve between approximately negative 25 and positive 25 millimeters.  Figure 32D presents the results for a 228.6-millimeter penetration, and shows a best-fit Gaussian distribution between approximately negative 30 and positive 30 millimeters, at an indication intensity of about 76 percent.  Overall this series of charts illustrates that, as the depth of penetration increases, the breadth of the beam diffraction also increases.

Figure 33.  Beam diffraction results for 11-degree, 2.25-megahertz, 12.7-millimeter diameter transducer.  Charts.  The figure consists of four charts that present results of the experimental beam diffraction tests obtained with the 11-degree, 2.25-megahertz, 12.7-millimeter-diameter transducer for four different penetration depths.  The X-axis on all four figures is distance in millimeters (negative 60 to positive 60) from maximum indication.  The Y-axis on all figures is the relative indication intensity in percent.  The first figure (33A) presents the results for a 76.2-millimeter penetration, and shows a best-fit Gaussian distribution or bell curve between approximately negative 20 and positive 20 millimeters, at an indication intensity of about 88 percent.  Figure 33B presents the results for a 127-millimeter penetration, and shows the bell curve between approximately negative 25 and positive 25 millimeters, at an indication intensity of about 78 percent.  The results for a 177.8-millimeter penetration, at an indication intensity of 80 percent, are shown in figure 33C as a bell curve between approximately negative 40 and positive 40 millimeters.  Figure 33D presents the results for a 228.6-millimeter penetration, and shows a best-fit Gaussian distribution between approximately negative 45 and positive 45 millimeters, at an indication intensity of about 78 percent. Overall this series of charts illustrates that, as the depth of penetration increases, the breadth of the beam diffraction also increases.

Figure 34.  Beam diffraction results for 14-degree, 2.25-megahertz, 12.7-millimeter diameter transducer.  Charts.  The figure consists of four charts that present results of the experimental beam diffraction tests obtained with the 14-degree, 2.25-megahertz, 12.7-millimeter-diameter transducer for four different penetration depths.  The X-axis on all four figures is distance in millimeters (negative 60 to positive 60) from maximum indication.  The Y-axis on all figures is the relative indication intensity in percent.  The first figure (34A) presents the results for a 76.2-millimeter penetration, and shows a best-fit Gaussian distribution or bell curve between approximately negative 15 and positive 15 millimeters, at an indication intensity of about 80 percent.  Figure 34B presents the results for a 127-millimeter penetration, and shows the bell curve between approximately negative 30 and positive 30 millimeters, at an indication intensity of about 82 percent.  The results for a 177.8-millimeter penetration, at an indication intensity of about 82 percent, are shown in figure 34C as a bell curve between approximately negative 40 and positive 40 millimeters.  Figure 34D presents the results for a 228.6-millimeter penetration, and shows a best-fit Gaussian distribution between approximately negative 50 and positive 50 millimeters, at an indication intensity of about 77 percent. Overall this series of charts illustrates that, as the depth of penetration increases, the breadth of the beam diffraction also increases.

Figure 35.  Beam diffraction results for 8-degree, 2.25-megahertz, 19-millimeter square transducer.  Charts.  The figure consists of four charts that present results of the experimental beam diffraction tests obtained with the 8-degree, 2.25-megahertz, 19-millimeter square transducer for four different penetration depths.  The X-axis on all four figures is distance in millimeters (negative 60 to positive 60) from maximum indication.  The Y-axis on all figures is the relative indication intensity in percent.  The first figure (35A) presents the results for a 76.2-millimeter penetration, and shows a best-fit Gaussian distribution or bell curve between approximately negative 10 and positive 10 millimeters, at an indication intensity of about 85 percent.  Figure 35B presents the results for a 127-millimeter penetration, and shows the bell curve between approximately negative 20 and positive 20 millimeters, at an indication intensity of about 82 percent.  The results for a 177.8-millimeter penetration, at an indication intensity of about 78 percent, are shown in figure 35C as a bell curve between approximately negative 25 and positive 25 millimeters.  Figure 35D presents the results for a 228.6-millimeter penetration, and shows a best-fit Gaussian distribution between approximately negative 30 and positive 30 millimeters, at an indication intensity of about 85 percent.  Overall this series of charts illustrates that, as the depth of penetration increases, the breadth of the beam diffraction also increases.

Figure 36.  Distance amplitude correction curve for 8-degree, 5-megahertz, 12.7-millimeter diameter transducer.  Chart.  The figure is a graph relating sound-path distance to indication intensity.  The X-axis is sound-path distance in millimeters (0 to 250), and the Y-axis is relative indication intensity in percent (0 to 90).  A best-fit exponential curve is shown decreasing from 80 percent relative indication intensity at a sound-path distance of 75 millimeters to about 12 percent relative indication intensity at a sound-path distance of 225 millimeters.

Figure 37.  Distance amplitude correction curve for 0-degree, 5-megahertz, 12.7-millimeter diameter transducer.  Chart.  The figure is a graph relating sound-path distance to indication intensity.  The X-axis is sound-path distance in millimeters (0 to 250), and the Y-axis is relative indication intensity in percent (0 to 90).  A best-fit exponential curve is shown decreasing from 80 percent relative indication intensity at a sound-path distance of 75 millimeters to about 15 percent relative indication intensity at a sound-path distance of 225 millimeters.

Figure 38.  Distance amplitude correction curve for 0-degree, 2.25-megahertz, 25.4-millimeter diameter transducer.  Chart.  The figure is a graph relating sound-path distance to indication intensity.  The X-axis is sound-path distance in millimeters (0 to 250), and the Y-axis is relative indication intensity in percent (0 to 90).  A best-fit exponential curve is shown decreasing from 80 percent relative indication intensity at a sound-path distance of 75 millimeters to about 22 percent relative indication intensity at a sound-path distance of 225 millimeters.

Figure 39.  Distance amplitude correction curve for 11-degree, 2.25-megahertz, 12.7-millimeter diameter transducer.  Chart.  The figure is a graph relating sound-path distance to indication intensity.  The X-axis is sound-path distance in millimeters (0 to 250), and the Y-axis is relative indication intensity in percent (0 to 90).  A best-fit exponential curve is shown decreasing from 80 percent relative indication intensity at a sound-path distance of 75 millimeters to about 10 percent relative indication intensity at a sound-path distance of about 225 millimeters.

Figure 40.  Distance amplitude correction curve for 14-degree, 2.25-megahertz, 12.7-millimeter diameter transducer.  Chart.  The figure is a graph relating sound-path distance to indication intensity.  The X-axis is sound-path distance in millimeters (0 to 250), and the Y-axis is relative indication intensity in percent (0 to 90).  A best-fit exponential curve is shown decreasing from 80 percent relative indication intensity at a sound-path distance of 75 millimeters to about 12 percent relative indication intensity at a sound-path distance of about 225 millimeters.

Figure 41.  Distance amplitude correction curve for 8-degree, 2.25-megahertz, 19-millimeter square transducer.  Chart.  The figure is a graph relating sound-path distance to indication intensity.  The X-axis is sound-path distance in millimeters (0 to 250) and the Y-axis is relative indication intensity in percent (0 to 90).  A best-fit exponential curve is shown decreasing from 80 percent relative indication intensity at a sound-path distance of 75 millimeters to about 18 percent relative indication intensity at a sound-path distance of 225 millimeters.

Figure 42.  Pin 1 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (A) and two graphical representations (B and C) of the scan results for end 1 of pin 1.  Figure 42A is a table of raw data recorded during inspection scanning of end 1 of pin 1.  Parameters included on the chart are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 42B is an elevation line drawing representing the pin. It shows the location of the crack as a dotted line, approximately 97 millimeters (3.8 inches) from end 1 of pin 1, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the crack.  Figure 42C is a cross-sectional representation of end 1 of pin 1, showing the location of peak signal strength at about 8 o’clock, which represents the location of the crack, and the range (7:30 to 8:30) about the circumference over which the typical signal was observed.

Figure 42.  (Continued) Pin 1 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (D) and two graphical representations (E and F) of the scan results for end 2 of pin 1.  Figure 42D is a table of raw data recorded during inspection scanning of end 2 of pin 1.  Parameters included on the chart are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 42E is an elevation line drawing representing the pin.  It shows the location of the crack as a dotted line, approximately 127 millimeters (5 inches) from end 2 of pin 1, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the crack.  Figure 42F is a cross-sectional representation of end 2 of pin 1, showing the location of peak signal strength at about 5 o’clock, which represents the location of the crack.

Figure 43.  Pin 2 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (A) and two graphical representations (B and C) of the scan results for end 1 of pin 2.  Figure 43A is a table of raw data recorded during inspection scanning of end 1 of pin 2.  Parameters included are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 43B is an elevation line drawing representing the pin.  It shows the location of two cracks as dotted lines, approximately 97 millimeters (3.8 inches) and 150 millimeters (5.9 inches) from end 1 of pin 2, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the cracks.  Figure 43C is a cross-sectional representation of end 1 of pin 2, showing the locations of peak signal strength at about 2 o’clock and 5 o’clock, which represent the locations of the crack. 

Figure 43.  (Continued) Pin 2 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (D) and two graphical representations (E and F) of the scan results for end 2 of pin 2.  Figure 43D is a table of raw data recorded during inspection scanning of end 2 of pin 2.  Parameters included are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 43E is an elevation line drawing representing the pin. It shows the location of two cracks as dotted lines, approximately 74 millimeters (2.9 inches) and 262 millimeters (5 inches) from end 2 of pin 2, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the cracks.  Figure 43F is a cross-sectional representation of end 2 of pin 2, showing the locations of peak signal strength at about 6:30 o’clock and 7:30 o’clock, and at 10 and 10:30 o’clock, which represent the locations of the cracks. 

Figure 44.  Pin 3 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (A) and two graphical representations (B and C) of the scan results for end 1 of pin 3.  Figure 44A is a table of raw data recorded during inspection scanning of end 1 of pin 3.  Parameters included are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 44B is an elevation line drawing representing the pin. It shows the location of two cracks as dotted lines, approximately 97 millimeters (3.8 inches) and 147 millimeters (5.8 inches) from end 1 of pin 3, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the cracks.  Figure 44C is a cross-sectional representation of end 1 of pin 3, showing the locations of peak signal strength at about 4:30 o’clock and 5 o’clock, and at 10:30 o’clock and 11 o’clock, which represent the locations of the cracks. 

Figure 44.  (Continued) Pin 3 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (D) and two graphical representations (E and F) of the scan results for end 2 of pin 3.  Figure 44D is a table of raw data recorded during inspection scanning of end 2 of pin 3.  Parameters included are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 44E is an elevation line drawing representing the pin. It shows the location of two cracks as dotted lines, approximately 74 millimeters (2.9 inches) and 262 millimeters (5 inches) from end 2 of pin 3, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the cracks.  Figure 44F is a cross-sectional representation of end 2 of pin 3, showing the locations of peak signal strength at about 6:30 o’clock and 7:30 o’clock, and at 12:30 and 1 o’clock, which represent the locations of the cracks.

Figure 45.  Pin 4 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (A) and two graphical representations (B and C) of the scan results for end 1 of pin 4.  Figure 45A is a table of raw data recorded during inspection scanning of end 1 of pin 4.  Parameters included are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 45B is an elevation line drawing representing the pin.  It shows the location of the crack as a dotted line, approximately 97 millimeters (3.8 inches) from end 1 of pin 4, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the crack.  Figure 45C is a cross-sectional representation of end 1 of pin 4, showing the locations of peak signal strength at about 12:30 o’clock and 1 o’clock, which represent the location of the crack. 

Figure 45.  (Continued) Pin 4 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (D) and two graphical representations (E and F) of the scan results for end 2 of pin 4.  Figure 45D is a table of raw data recorded during inspection scanning of end 2 of pin 4.  Parameters included are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 45E is an elevation line drawing representing the pin.  It shows the location of a crack as a dotted line, approximately 127 millimeters (5 inches) from end 2 of pin 4, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the crack.  Figure 45F is a cross-sectional representation of end 2 of pin 4, showing the locations of peak signal strength at about 11 o’clock, which represents the location of the crack, and the range (10 to 12 o’clock) about the circumference over which the typical signal was observed.

Figure 46.  Pin 5 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (A) and two graphical representations (B and C) of the scan results for end 1 of pin 5.  Figure 46A is a table of raw data recorded during inspection scanning of end 1 of pin 5.  Parameters included are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 46B is an elevation line drawing representing the pin.  It shows the location of the crack as a dotted line, approximately 97 millimeters (3.8 inches) from end 1 of pin 5, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the crack.  Figure 46C is a cross-sectional representation of end 1 of pin 5, showing the locations of peak signal strength from 6 to 7 o’clock, and the range (5:30 to 7 o’clock) about the circumference over which the typical signal was observed.

Figure 46.  (Continued) Pin 5 testing results.  Chart and Drawings.  This figure consists of a chart presenting the raw inspection data (D) and two graphical representations (E and F) of the scan results for end 2 of pin 5.  Figure 46D is a table of raw data recorded during inspection scanning of end 2 of pin 5.  Parameters included are scan angle (degrees), indication level (decibels), reference level (decibels), reading location (hours and minutes), beginning of signal location (hours and minutes), end of signal location (hours and minutes), distance to index (inches), sound path distance (inches), axial distance (inches), and radial distance (inches).  Figure 46E is an elevation line drawing representing the pin.  It shows the location of a crack as a dotted line, approximately 129 millimeters (5.1 inches) from end 2 of pin 5, and also the centerline path of the ultrasonic beam as it travels from the transducer (on the left) to the crack.  Figure 46F is a cross-sectional representation of end 2 of pin 5, showing the locations of peak signal strength at about 6 o’clock, which represents the location of the crack, and the range (5:30 to 7 o’clock) about the circumference over which the typical signal was observed.

Figure 47.  Photograph of pulse-echo setup using 14-degree transducer.  Color Photograph.  This figure is a color photograph of the pulse-echo setup with a 14-degree transducer used during the acoustic coupling tests.  The photograph shows a hand holding the transducer at the end of the pin, which is held in place by a test frame.

Figure 48.  UT scan utilizing pulse-echo technique with a 14-degree transducer.  Charts.  This figure consists of printouts from 11 pulse-echo ultrasonic testing scans conducted with a 14-degree transducer.  Each scan represents a sequentially decreasing applied load.  Figure 48A represents load step 1 at 88.96 kilonewtons; figure 48B represents load step 2 at 84.51 kilonewtons; figure 48C represents load step 3 at 80.07 kilonewtons; figure 48D represents load step 4 at 75.62 kilonewtons; figure 48E represents load step 5 at 71.17 kilonewtons; figure 48F represents load step 6 at 66.72 kilonewtons; figure 48G represents load step 7 at 62.28 kilonewtons; figure 48H represents load step 8 at 57.83 kilonewtons; figure 48I represents load step 9 at 53.38 kilonewtons; figure 48J represents load step 10 at 48.93 kilonewtons; and figure 48K represents load step 11 at 44.48 kilonewtons.  Overall, the scan series shows that the intensity of the signal decreases as the applied load is decreased.

Figure 49.  Photograph of pitch-catch setup using 0-degree transducers.  Color Photograph.  This figure is a color photograph of a pitch-catch setup with two 0-degree transducers used during the acoustic coupling tests.  The photograph shows a hand holding the transmitting transducer at the right end of the pin, which is held in place by a test frame.  Another hand is holding the receiving transducer at the left side of the test frame.

Figure 50.  UT scan utilizing pitch-catch technique using 0-degree transducers.  Charts.  This figure consists of printouts from 20 pitch-catch ultrasonic testing scans, using two 0-degree transducers.  Each scan represent a sequentially increasing applied load.  Figure 50A represents load step 1 at 0 kilonewtons; figure 50B represents load step 2 at 8.89 kilonewtons; figure 50C represents load step 3 at 13.34 kilonewtons; figure 50D represents load step 4 at 17.79 kilonewtons; figure 50E represents load step 5 at 22.24 kilonewtons; figure 50F represents load step 6 at 26.69 kilonewtons; figure 50G represents load step 7 at 31.14 kilonewtons; figure 50H represents load step 8 at 35.59 kilonewtons; figure 50I represents load step 9 at 40.03 kilonewtons; figure 50J represents load step 10 at 44.48 kilonewtons; figure 50K represents load step 11 at 48.93 kilonewtons, figure 50L represents load step 12 at 53.38 kilonewtons; figure 50M represents load step 13 at 57.82 kilonewtons; figure 50N represents load step 14 at 62.28 kilonewtons; figure 50O represents load step 15 at 66.72 kilonewtons; figure 50P represents load step 16 at 71.17 kilonewtons, figure 50Q represents load step 17 at 75.62 kilonewtons; figure 50R represents load step 18 at 80.07 kilonewtons; figure 50S represents load step 19 at 84.52 kilonewtons; and figure 50T represents load step 20 at 88.96 kilonewtons.  Overall, the scan series shows that the intensity of the signal increases as the applied load is increased.

Figure 51.  Photograph of pitch-catch setup using 0-degree receiving and 14-degree transmitting transducers.  Color Photograph.  This figure is a color photograph of a pitch-catch setup with one 0-degree receiving transducer and one 14-degree transmitting transducer used during the acoustic coupling tests.  The photograph shows a hand holding the 14-degree transmitting transducer at the right end of the pin, which is held in place by a test frame.  Another hand is holding the 0-degree receiving transducer on the left side of the test frame.

Figure 52.  UT scan utilizing pitch-catch technique using 0-degree and 14-degree transducers.  Charts.  This figure consists of printouts from 21 pitch-catch ultrasonic testing scans, using 0-degree and 14-degree transducers.  Each scan represent a sequentially decreasing applied load.  Figure 52A represents load step 1 at 88.96 kilonewtons; figure 52B represents load step 2 at 84.52 kilonewtons; figure 52C represents load step 3 at 80.07 kilonewtons; figure 52D represents load step 4 at 75.62 kilonewtons; figure 52E represents load step 5 at 71.17 kilonewtons; figure 52F represents load step 6 at 66.72 kilonewtons; figure 52G represents load step 7 at 62.28 kilonewtons; figure 52H represents load step 8 at 57.83 kilonewtons; figure 52I represents load step 9 at 53.38 kilonewtons; figure 52J represents load step 10 at 48.93 kilonewtons; figure 52K represents load step 11 at 44.48 kilonewtons, figure 52L represents load step 12 at 40.03 kilonewtons; figure 52M represents load step 13 at 35.59 kilonewtons; figure 52N represents load step 14 at 31.14 kilonewtons; figure 52O represents load step 15 at 26.69 kilonewtons; figure 52P represents load step 16 at 22.24 kilonewtons, figure 52Q represents load step 17 at 17.79 kilonewtons; figure 52R represents load step 18 at 13.34 kilonewtons; figure 52S represents load step 19 at 8.90 kilonewtons; figure 52T represents load step 20 at 4.45 kilonewtons, and figure 52U represents load step 21 at 0 kilonewtons.  Overall, the scan series shows that the intensity of the signal decreases as the applied load is decreased.


Equations

Equation 1. Frequency, F, times wavelength, lambda, equals the velocity of sound, C.

Equation 2. For longitudinal waves, C subscript L equals the square root of the product of the quotient of the modulus of elasticity, E, divided by density, phi, times the quotient of 1 minus Poisson’s ratio, mu, divided by the product of 1 plus mu times 1 minus 2 times mu.

Equation 3. For shear waves, C subscript S equals the square root of the product of E divided by phi, times the quotient of 1 divided by the product of 1 plus mu times 2.  This then equals the square root of the shear modulus, G, divided by phi.

Equation 4. C subscript S divided by C subscript L equals the square root of the quotient of 1 minus 2 times mu divided by 2 times 1 minus mu.

Equation 5. Decibel, DB, equals 10 times the log of 10 times the quotient of the measured power, P, divided by P subscript 0.

Equation 6. DB equals 10 times the log of 10 times the quotient of the voltage, V, divided by V subscript 0, squared.

Equation 7. DB equals 20 times the log of 10 times the quotient of V divided by V subscript 0.

Equation 8. The beam spread angle, beta, equals sine negative 1 of the quotient of 0.61 times wavelength, lambda, divided by the transducer active radius, alpha.

Equation 9. Axial distance equals the sound path, SP, times the cosine of the transducer angle, theta.

Equation 10. Radial distance equals the distance to index, DI, plus SP times the sine of theta.

Equation 11. Axial distance equals SP times the cosine of theta plus or minus the beam spread angle, beta.

Equation 12. Radial distance equals DI plus SP times the sine of theta plus or minus beta.

Equation 13. The distance to a potential shear plane, D subscript 1, equals the distance from the face of pin to the face of hanger, FH subscript 1, plus the measured thickness of hanger, lowercase T subscript H1, plus the measured gap width between the suspended span web and hanger plate, lowercase T subscript lowercase G1, plus the measured thickness of the web, lowercase T subscript W.

Equation 14. D subscript 2 equals the distance from face of pin to face of web, FW subscript 1, plus lowercase T subscript W.

Equation 15. D subscript 3 equals the length of pin (measured or design), L, minus the product of FH subscript 2 plus lowercase T subscript H2 plus lowercase T subscript G2.

Equation 16. D subscript 4 equals L minus FW subscript 2.

Equation 17. D equals the sum of D subscript 1 plus D subscript 2 plus D subscript 3 plus D subscript 4, all divided by 4.

 
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