Open Collections

Abstract

Rotational stiffness of T-joints in laser-welded web-core sandwich panels is finite. Considering it infinite is convenient to avoid computational cost associated with determining the actual stiffness. This study investigates whether the assumption of infinite rotational stiffness for a broad range of panels in optimization leads to sub-optimal panels in comparison to panels optimized considering real rotational stiffness. Global op-timization of panels’ buckling load and first natural frequency is performed. Structural analysis is conducted using equivalent single layer model, and the results are validated using detailed FEA. Comparing panels with infinite weld stiffness and the ones where weld thickness is 25% of web plate thickness, maximum reduction of buckling load is 32% and of natural frequency by 17%. Moreover, if infinite stiffness assumption is used in optimization and finite weld stiffness is implemented afterwards, sub-optimal designs might be obtained, with up to 6% lower buckling load and 15% lower natural frequency than panels optimized with finite rotational stiffness. Thus, for higher accuracy it is recommended to consider finite rotational weld stiffness although com-putational time for optimization has been increased by 24%.