The Influence of Friction Stir Welding Process Idealization on Residual Stress and Distortion Predictions for Future Airframe Assembly Simulations

Abstract

The ability to accurately predict residual stresses and resultant distortions is a key product from process assembly simulations. Assembly processes necessarily consider large structural components potentially making simulations computationally expensive. The objective herein is to develop greater understanding of the infiuence of friction stir welding process idealization on the prediction of residual stress and distortion and thus determine the minimum required modeling fidelity for future aiiframe assembly simulations. The combined computational and experimental results highlight the importance of accurately representing the welding forging force and process speed. In addition, the results emphasize that increased CPU simulation times are associated with representing the tool torque, while there is potentially only local increase in prediction fidelity.

The influence of assembly friction stir weld location on wing panel static strength

“…The perfect mesh of the test specimen, without edge stringers or frames, is modelled with the idealised post weld residual stress state and with minimum boundary conditions to prevent rigid body translations or rotations. This step represents the unclamping of the welded skin and stringers from their fixturing required for the welding process [37][38]. When the residual stresses are introduced to the model, the structure is no longer in equilibrium, and a nonlinear geometric analysis is carried out to establish static equilibrium.…”

An Integrated Approach to Additive Manufacturing Simulations Using Physics Based, Coupled Multiscale Process Modeling

“…Some of the previous work on thermal stresses and distortions were conducted earlier in the literature assuming linear, nonlinear, and large deformation constructs for welding scenarios and using the profiles in AM to look at the part errors [27][28][29][30].…”

Impact of finite element idealisation on the prediction of welded fuselage stiffened panel buckling

“…The equilibrium calculation generates a distorted structure, and a slightly modified stress state. This step represents the unclamping of the assembled structure from any fixturing required during the welding process [30]. A second stage simulation is then required to represent additional manufacturing processes, for example attaching the riveted stiffeners of specimen S7 and test preparation processes such as clamping and casting specimen ends.…”