Applicability of Cyclic Stress Measurement Method Using Electrodeposited Copper Foil to Out-of-Phase Loading

Abstract

The applicability of stress measurement method using electrodeposited copper foil under combined stress state of out-of-phase tension and torsion was examined. The density of grains grown by cyclic loading was measured and the crystallographic orientation of grains was also analyzed by EBSD. The pole figure suggests that grains grow in the direction of Tresca equivalent shear stress and the normal stress acting on the plane of Tresca equivalent shear stress also affects the grain growth. The equivalent shear stress that dominates the grain growth density is proposed to the condition of out-of-phase loading. Based on these results, stress measurement is possible by using the density and the crystallographic orientation of grown grains. However, this method can be applied only when the phase difference of tension and torsion is known and not equal to π/2.