Global sensitivity analysis of mechanical properties in hybrid single lap aluminum-CFRP (plain woven) joints based on uncertainty quantification

Though characterized with extraordinary mechanical performance, the application of hybrid joint (HJ) is restricted due to its numerous parameters and complex nonlinearities in design process. Sensitivity analysis can effectively simplify the HJ design by identifying the dominant parameters in the initial design stage. In this work, uncertainty quantification (UQ) tool was adopted to comprehensively analyze the global sensitivity of the mechanical properties in hybrid (bonded/riveted) single lap aluminum-CFRP joints. A three-dimensional finite element model considering material failure was established and verified by experiments. Besides multiple experimentally quantified uncertainty sources arising from material, geometry and assembly were introduced in the mechanical performance simulation. Meanwhile, the relative contribution of different joint parameters to load sharing, stiffness and peak load was quantified by a high-efficient stochastic sensitivity analysis strategy based on polynomial chaos expansion (PCE) and Sobol decomposition. Then the key parameters affecting the stochastic mechanical properties were identified. Finally, the physical meaning of the sensitivity analysis result was explained. Results show that the proposed method can efficiently and accurately determine the important parameters in the HJ design, which can be applied to improve the design efficiency and quality of HJs.