Three-dimensional numerical simulation of weld solidification cracking

Abstract

It is difficult to measure mechanical strain in the vicinity of a moving weld pool owing to the complex solidification process. Computational modelling of the welding process provides an effective method to study the stress/strain distributions of the weldment. In this paper, the driving force to weld solidification cracking, i.e. mechanical strain versus temperature at the trail of a weld molten pool, was modelled with the three-dimensional finite element analysis procedure. The dynamic stress/strain evolutions that contribute to the formation of solidification cracking have been calculated in the cracking susceptible temperature range. In the mechanical model, solidification effects, namely deformation in the weld pool, change of initial temperature for thermal stress/strain calculation, were treated by means of a dynamic element rebirth scheme. Solidification shrinkage was also taken into consideration in simulation. The results of comparison between the calculated driving force and the experimental measurements of the material resistance predict the susceptibility of solidification cracking.

Effect of weld travel speed on solidification cracking behavior. Part 3: modeling

“…Modeling these effects and their impact on solidification crack formation remains a difficult subject. Therefore, only multi-scale, multi-physics models, as the ones used to investigate weldability and solidification cracking behavior [85][86][87][88][89][90][91][92][93][94][95][96][97][98] [99,100], can efficiently simulate welding speed effect on solidification crack formation. Complex simulations to describe the travel speed effect must include modeling both microstructure and thermo-mechanical cells with the implementation of solidification cracking criteria.…”

Experimental and numerical analysis of solidification cracking behaviour in fibre laser welding of 6013 aluminium alloy

“…Up to date, parameters such as mechanical strain, 22,24,25,35 plastic strain 23 and plastic strain rate 26,27 have been used to analyse the crack initiation. In this study, the mechanical strain was adopted to analyse the solidification cracking behaviour.…”

Numerical modeling of inconel 738LC deposition welding: Prediction of residual stress induced cracking

“…When the material is liquid, the related rigidity and resistance are negligible, but both yielding strength and Young modulus were not considered to be nil in order to reduce computation times, but they were limited to small values (5 MPa and 0.1 GPa respectively) around which any deviation does not modify the mechanical results. Similarly, as commonly used and justified elsewhere, the related thermal expansion coefficient was considered very small in order to avoid computation divergence (Taleb et al, 2004;Wei et al, 2005;Taljat et al, 1998). Furthermore, after incorporating a viscous contribution in the constitutive law representing the alloy behavior at high temperature, comparisons between computed and experimental results showed that the lower the viscous contribution, the smaller the deviations are.…”