MS6: From numerical modeling of forming processes down to in-use properties

Animators: E. Rouhaud (UTT, France), M. Lévesque (Polytech Montreal, Canada)
Scientific Committee: P. Olivier Bouchard (CEMEF, France), M. François (UTT, France), D. Retraint (UTT, France), JL Duval (ESI, France), A. Roos (Safran Tech, France), H.Y. Miao (Polytech Montreal, Canada), D. Li (Shanghai Jiao Tong University, China), S.H. Zhang (Chinese Academy of Sciences, China).

Objectives: Numerical simulations of manufacturing processes have been developed with the first intention of optimizing process parameters. These models are now accurate enough to provide useful input data for in-use strength analyses, the ultimate objective being fatigue life enhancement and weight reduction. To reduce weight and satisfy in use constraints, new approaches appear that are based on the chaining of simulations hence gathering manufacturing simulation (stamping, casting, Forging, assembly) and fatigue analysis. An important issue is to determine which information is relevant and how to transfer this information from manufacturing simulation and fatigue analyses model. Within this "virtual chain" of simulations, thermo-mechanical and thermo-chemical treatments (quenching, shot peening, carbonitriding…) possibly applied to the part after forming need consideration. Specifically, residual stresses have an important impact on fatigue life of mechanical components in service. A key issue is thus the prediction of residual stresses coming from forming and surface treatment stages and their impact on fatigue analysis. For other processes involving high plastic strain, damage may start during the forming stage without giving rise to crack initiation. Accounting for this damage "history" in the subsequent structural analysis is mandatory if one wants to predict accurately components mechanical strength.

The objective of this mini-symposium is to gather contributions concerning modeling and numerical simulations of forming and manufacturing processes and centered on the consequences (residual stress field, damage, material parameters, relaxation…) of the process. Models and numerical methods developed to predict components fatigue life and mechanical strength will be also highlighted.