A Novel Collaborative Optimization Model for the Thermally Induced Buckling Issue of Stiffened Thin‐Walled Structures

ABSTRACT The structural stability and stiffness are both crucial for maintaining aerodynamic profiles of stiffened thin‐walled structures, especially in aerospace applications when subjected to extreme thermal loading. One of the challenges arises from significant compression loads induced by the restricted thermal expansion, leading to thermally induced buckling issues and severe thermal deformation. Existing methods lack choice and inevitably rely on room‐temperature optimization models in thermal buckling designs, leading to an irreconcilable contradiction between the optimized thermal buckling and thermal stiffness performances. This study focuses on the collaborative design of buckling resistance and stiffness reinforcement for mitigating deformation failure in stiffened thin‐walled structures and proposes a novel collaborative optimization model that maximizes the critical buckling load factor (BLF) under volume and regional strain energy constraints, namely BVR model. Compared with the conventional model that maximizes the critical BLF under volume and compliance constraints (BVC), the comparison results demonstrate the advantage of the proposed method in ensuring structural clarity, stability, and stiffness of optimal designs through typical and complex numerical examples. The failure reason for the conventional model is also given. For an aft deck structure under thermal loading, the proposed method increases the critical BLF by 98.7% and reduces the thermal deformation by 63.6%.