アルミニウム合金の応力集中部における塑性ひずみに起因される非線形超音波特性の変化

抄録

An annular notch was introduced into a round bar specimen of aluminum alloy A2017, and changes in nonlinear acoustic properties due to plastic strain generated at the bottom of the notch when tensile stress was applied were investigated using axial shear-wave EMAT, which transmits and receives SH waves propagating in the circumferential direction of the specimen. It was found that the nonlinearity of the harmonic components increased rapidly with increasing tensile stress. Elastic-plastic finite element analysis revealed that the increase in local plastic strain occurring at stress concentrations corresponds to the change in nonlinearity due to the harmonics. This method has the potential to capture microstructural changes in metal at stress concentrations.