Structural Static/Fatigue/Damage Tolerance Comprehensive Design Optimization of Composite Laminate

This paper develops a structural static/fatigue/damage tolerance comprehensive design method for composite laminated structures under mechanical–thermal coupling environments. The developed design method can finely quantify the additional stress and deformation caused by the mechanical–thermal coupling effect. In addition, a new damage evolution-based fatigue reliability evaluation method is proposed, and the structural fatigue behavior can be described and predicted. The different failure modes of composite material and their correlations are considered during the damage evolution analysis. The structural possible accidental damage can also be taken into account by applying the global preset damage in design stage. Thus, the static requirement, fatigue requirement, and damage tolerance requirement can all be considered simultaneously during the design process. The structural comprehensive design of composite laminate is conducted by virtue of the two-level optimization method. A case of a notched composite laminate is employed to verify the proposed method. In addition, a case of a civil aircraft wing structure is used to explain the feasibility of the developed method in dealing with structural design problems in engineering.