Nonlinear bending of unsymmetric double-layer lattice truss core sandwich beams

This paper studied the nonlinear bending of unsymmetric double-layer lattice truss core sandwich beams (LTCSBs). Five unsymmetric cases are considered by varying different materials and geometric thicknesses in two layers. To establish a theoretical model for the unsymmetric double-layer LTCSBs, Allen's model and von Karman nonlinear theory are employed. The present theoretical model is established by considering the midplane of the mid-sheet as the reference plane. Ritz method is applied to determine the deflection for the nonlinear bending, and verified by the finite element method (FEM). Finally, the effects of the loading direction, unsymmetric factors, and boundary conditions on the nonlinear bending behaviors of LTCSBs are studied. It is found that the nonlinear deflections of unsymmetric LTCSBs may exhibit softening-spring nonlinearity in one direction.

Automated summary

This paper investigates the nonlinear bending behavior of unsymmetric double-layer lattice truss core sandwich beams (LTCSBs). A theoretical model based on Allen's model and von Karman nonlinear theory is established, with the midplane of the mid-sheet as the reference plane. The deflection for nonlinear bending is determined using the Ritz method and validated by the finite element method. The study reveals that the nonlinear deflections of unsymmetric LTCSBs can exhibit softening-spring nonlinearity in one direction.