Effect of time-dependent material properties on the welding-induced residual stress and distortion fields of aluminum stiffened plates

摘要

This paper presents results of a numerical study on the effect of varying temperature dependent material properties on welding simulation of aluminum stiffened plates using finite element software ANSYS. The material properties studied in this paper include the thermal conductivity, specific heat, thermal density, Young's modulus, yield strength and thermal expansion. For each property, three sets of values are considered including 1) values that are functions of temperature, 2) values obtained at room temperature, and 3) values averaged over the entire temperature history. The simulation is conducted using sequentially coupled thermal and structural analyses. In the thermal analysis, the time-dependant temperature field by the welding process is determined using an element birth and death technique to model the addition of weld metal to the workpiece. In structural analysis, the temperature history from the thermal analysis is applied as loads to the workpiece to generate three dimensional residual stresses and distortion fields. The model is verified with experimental results. The numerical results are discussed in terms of residual stress and distortion in the stiffened plate as affected by varying material properties in the simulation. Conclusions and recommendations are presented as appropriate.