Convenient estimation of elastic, plastic and creep constitutive equations for solder under tensile test of constant strain rate with loading, unloading and reloading paths

Abstract

The deformation of solder shows the unique characteristics which differs from one of other engineering materials remarkably, as it is accompanied with the large creep deformation at room temperature. This deformation behaviour appears in a typical stress-strain relationship in loading, unloading and reloading path. In the present study, the tensile test of Sn-37Pb solder subjected to loading, unloading and reloading under a constant strain rate was carried out at room temperature. The constitutive equations of elasticity, plasticity and creep of the tested material were independently obtained from the stress-strain relationship under loading or reloading path. A typical stress-strain relationship of Sn-37Pb solder with time-dependent deformation was correctly reproduced by the simulation of the numerical analysis of the Runge-Kutta method and the finite element method using these constitutive equations.