Reliability-based design optimization of structural systems under hybrid probabilistic and interval model

• HPRMM is proposed to estimate the objective function.
• HPIMM is proposed to evaluate the component reliability.
• RBDO based on HPRMM and HPIMM is developed.
• Effectiveness of RBDO based on HPRMM and HPIMM are investigated.

Reliability-based design optimization (RBDO) under hybrid probabilistic and interval model is a nested loop optimization whose computational cost rising from evaluation of the objective function and the component reliability is considerable. To improve its computational efficiency, a hybrid perturbation random moment method (HPRMM) to estimate the objective function and a hybrid perturbation inverse mapping method (HPIMM) to evaluate the component reliability will be proposed. Based on HPRMM and HPIMM, the nested loop optimization is converted into an efficient single-loop process. Effectiveness and efficiency of proposed approaches are checked by solving optimization problems of a structural–acoustic system and a disc brake system.