A developed theoretical analysis method for predicting the response of a bimodular composite sandwich beam

A common problem of anisotropic materials is that the modulus of elasticity is not equal in tension and compression. Presently, research objects are mainly concentrated on beams with isotropic materials or laminated beams with orthotropic materials, and few are involved in composite sandwich beams with different moduli in tension and compression. Considering the shortcomings of the equivalent area method, we propose a developed theoretical analysis method for analyzing sandwich beams with different moduli in tension and compression based on the idea of layering. In this method, the sandwich beam is divided into four layers: upper panel, lower panel, tension zone of core, and compression zone of core. In addition, based on general weighted flexibility matrix material model and its simplified model, a finite element simulation model with high computational efficiency and good convergence is established. A comparison between the theoretical calculation results and the finite element results shows that the developed theoretical analysis method proposed in this paper has a higher accuracy than the equivalent area method, regardless of different types of loads or conditions with a large ratio of tensile to compressive elastic modulus.