Advanced probabilistic design and reliability-based design optimization for composite sandwich structure

Abstract

A composite sandwich structure can improve flexural rigidity and can decrease the weight of a composite laminated plate by 30%. However, it implies significant uncertainty within the construction process of its material properties when compared to other regular metals. Therefore, it is necessary to consider a probabilistic design method based on reliability. This paper calculated the probabilistic margin of safety of a simplified composite sandwich fuselage in order to examine that the classic design method utilizing the safety factor does not ensure the safety of the structure. Reliability-based design optimization (RBDO) was conducted for efficient calculation by using proposed RBDO by moving probability density function (RBDO-MPDF) method in this paper. Crude Monte-Carlo Simulation was used to calculate the probability density function. The results of this paper will be applicable to the improved design methods that ensure the structural reliability and maximized efficiency within the RBDO process.

Keywords:

• composite sandwich
• uncertainty
• reliability analysis
• probabilistic margin of safety
• RBDO by moving PDF

Acknowledgments

This study was supported by the Flight Vehicle Research Center.