Vol.62, No.2, 2020, pp.1-20, doi:10.3970/cmc.2014.040.001
OPEN ACCESS
RESEARCH ARTICLE
A Real-time Monitoring Technique for Local Plasticity in Metals Based on Lamb Waves and a Directional Actuator/Sensor Set
  • Y. L. Liu1, N. Hu2, H. Xu3, H. Ning1, L. K. Wu1
Department of Mechanical Engineering, Chiba University, Chiba, Japan.
College of Aerospace Engineering, Chongqing University, Chongqing, China.
Mechanical and Electrical Engineering Institute, Beijing University of Chemical Technology, Beijing 100029, China.
Abstract
A real-time monitoring technique for local plasticity using Lamb waves was developed. Tensile test of a thin aluminum plate with a circular hole where high stress concentration was induced was conducted to verify this technique. During the tensile test, a series of wave signals passing through the local plastic region were collected using a directional actuator/sensor set to monitor plasticity evolution. A pulse compression technique was used to process the wave signals. With the increase of tensile stress in the specimen, the amplitude changes of S0 and A0 modes were obtained and the difference of Lamb wave signals was further evaluated using a proposed signal index I calculated by wavelet analysis. Combined with the numerical stress analysis of the tensile specimen, the influence of the plasticity on the amplitudes of S0 and A0 wave modes was analyzed. As the plastic zone grows gradually, the wave amplitudes and I of S0 and A0 wave modes show their different change tendencies compared with those in elastic stage. The amplitude change is more sensitive to mild plasticity than that of I, while the change of I caused by severe plasticity is more obvious than the amplitude change.
Keywords
Lamb waves, local plasticity, pulse compression technique, wavelet analysis.
Cite This Article
Liu, Y. L., Hu, N., Xu, H., Ning, H., Wu, L. K., et al (2020). A Real-time Monitoring Technique for Local Plasticity in Metals Based on Lamb Waves and a Directional Actuator/Sensor Set. CMC-Computers, Materials & Continua, 62(2), 1–20.