ISSN:
1741-2765
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract A technique for measuring the energy sensed at an acoustic-emission transducer is presented that utilizes a squaring circuit and digital integrator. Theoretical relationships between energy and other more conventional acoustic-emission parameters, such as counts and RMS voltage, are derived for certain idealized cases. Experimental results from the following types of tests are presented: (1) unflawed tensile (‘continuous’ emission); (2) precracked stress-corrosion cracking; (3) precracked fracture toughness; and (4) fatigue-crack growth. Energy, counts, RMS-voltage, energy/event and counts/event measurements are included. In the case of unflawed tensile specimens, energy techniques appeared somewhat superior to counts. In all other cases, a direct relationship between counts and energy was obtained. Energy measurements tended to give a larger weight to higher amplitude events. Other than this, energy measurements appeared to have no advantage over counts. The theoretical relationship predicted between energy/event and count/event agreed quite well with experimental observations. Overall, the test results presented indicate that energy techniques provide no significant advantage over counting threshold crossings in cases in which crack extension in metals is the primary source of acoustic emission.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02326321
