Thermo-mechanical Buckling

Figure 1: Stiffened CFRP panel: Comparison of computed and measured deformations

Thermal loading - purely applied or in combination with mechanical loading - can effect buckling. Structures as part of supersonic transport aircrafts and of reentry bodies are examples from the aerospace field. In addition to mechanical strains, the stresses and deformations due to thermal loading are included within the definition of structural models for buckling behaviour simulation. Figure 1 demonstrates good agreement between computed and measured shapes of a stiffened panel. Design rules based on combination of pure mechanical and pure thermal buckling loads are developed. Within the temperature limits of actually used CFRP materials there is no significant influence of thermal loading on buckling of panels, if the loading is unidirectional and if the laminate set-up makes sense as to pure mechanical loading. However, with multidirectional loading the situation is different, depending on laminate set-up and on significance of the thermal loading. Optimizations have to be performed in order to develop design rules.