44 Acoustic Emission Characteristics of Defects …
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engineering application for this lager truss beam. Therefore, the cylindrical location
method can be used to locate the acoustic emission sources for the truss beam.
44.3 Experiments
44.3.1 Instruments
The loading device is YE-5000 four-column hydraulic pressure testing machine used
for the three-point bending test. The maximum test load is 23t.
The AE measurements were realized with the AE system AMSY-6 (VallenSystem, Icking, Germany) including sensors, preamplifiers, computer software,
cables etc. The broadband AE sensors are VS900-M, VS45-H and resonant sensor
is VS150-RIC. The bandwidths of the VS900-M, VS45-H and VS150-RIC are 100–
900 kHz, 45–450 kHz and 100–450 kHz, respectively. The preamplifiers had 40 dB
gains with a 20–1000 kHz bandpass filter. The AE acquisition settings threshold is
39 dB used for the test.
44.3.2 Specimen
The test specimen used in this test is a section of a real crawler crane beam, which
is made up of four tubular chords and multiple web rods. The truss beam length is
9000 mm, and the side length of cross section is 1350 mm. The beam is in the state
of new manufacture delivery, and its appearance and test site are shown in Fig. 44.5.
The material of the truss beam is BJ770, which yield strength is 770 MPa and tensile
strength is 820 MPa.
44.3.3 AE Sensors Layout and Artificial Defect
During the test, a total of 10 AE sensors are arranged on the specimen, and the
layout of AE sensors is shown in Fig. 44.6. At the same time, in order to study the
acoustic emission signal characteristics of crack propagation, three artificial cracks
were prefabricated on the main chord and web rod respectively. The location of three
artificial cracks is shown in Fig. 44.6. The coordinates of the three artificial defect
centers are (0, 420), (0, 520), (200, 480). The location of each channel and artificial
defect were located correctly. Figure 44.7 shows the location results of each AE
sensor, and Fig. 44.8 shows the location result of defect 2.
507
engineering application for this lager truss beam. Therefore, the cylindrical location
method can be used to locate the acoustic emission sources for the truss beam.
44.3 Experiments
44.3.1 Instruments
The loading device is YE-5000 four-column hydraulic pressure testing machine used
for the three-point bending test. The maximum test load is 23t.
The AE measurements were realized with the AE system AMSY-6 (VallenSystem, Icking, Germany) including sensors, preamplifiers, computer software,
cables etc. The broadband AE sensors are VS900-M, VS45-H and resonant sensor
is VS150-RIC. The bandwidths of the VS900-M, VS45-H and VS150-RIC are 100–
900 kHz, 45–450 kHz and 100–450 kHz, respectively. The preamplifiers had 40 dB
gains with a 20–1000 kHz bandpass filter. The AE acquisition settings threshold is
39 dB used for the test.
44.3.2 Specimen
The test specimen used in this test is a section of a real crawler crane beam, which
is made up of four tubular chords and multiple web rods. The truss beam length is
9000 mm, and the side length of cross section is 1350 mm. The beam is in the state
of new manufacture delivery, and its appearance and test site are shown in Fig. 44.5.
The material of the truss beam is BJ770, which yield strength is 770 MPa and tensile
strength is 820 MPa.
44.3.3 AE Sensors Layout and Artificial Defect
During the test, a total of 10 AE sensors are arranged on the specimen, and the
layout of AE sensors is shown in Fig. 44.6. At the same time, in order to study the
acoustic emission signal characteristics of crack propagation, three artificial cracks
were prefabricated on the main chord and web rod respectively. The location of three
artificial cracks is shown in Fig. 44.6. The coordinates of the three artificial defect
centers are (0, 420), (0, 520), (200, 480). The location of each channel and artificial
defect were located correctly. Figure 44.7 shows the location results of each AE
sensor, and Fig. 44.8 shows the location result of defect 2.