Residual stress determination with acoustic birefringence in slightly anisotropic polymers

Abstract

The acoustic birefringence method has been used since a long time for metallic materials to detect residual stresses. This method is rarely used for polymers and composites due to the strong attenuation of the acoustic signal. Moreover, for thermoplastic polymer, with a slight anisotropy (known as texture for metals), coupling with applied stresses, extends the complexity of the residual stresses determination. The slight anisotropy of thermoplastic polymer should be studied with shear waves prior to the residual stress determination. If the material is perfectly isotropic, we are able to detect and quantify the residual stresses. If the material is slightly anisotropic, it is also possible to evaluate residual stresses by taking into account the directions of the principal axes of material anisotropy. POLYM. ENG. SCI., 55:2307–2312, 2015. © 2015 Society of Plastics Engineers

Measurement of the stress of steel members using the ultrasonic phase spectrum

“…1 Since expressions of velocities of elastic waves in stressed solids were derived by Hughes and Kelly, 2 which laid a foundation for acoustoelasticity, considerable possibilities of applying developments in acoustoelasticity to create nondestructive ultrasonic techniques have opened up. [3][4][5] Presently investigated nondestructive ultrasonic techniques of measuring the uniaxial stress of steel members are the shear-wave method, [6][7][8][9] longitudinal wave method, 8,9 surface wave method, 10,11 guided wave method, 12,13 and longitudinal critically refracted (Lcr) wave method. [14][15][16][17][18] The present paper focuses on the shear-wave method.…”