Semi-analytic approach for sandwich plate U-bending considering shear deformation of the core

The deformation mechanism of a sandwich plate during U-bending was theoretically investigated by rigid-plastic analysis considering shear deformation of the core and the frictional effect. The deformed shapes of a sandwich plate, which were described as a combination of straight lines and arcs, were calculated by Newton method to minimize the total internal work dissipation. Homogenized properties of core shear stress–shear strain curves calculated by using pure shear FE-analyses were used in the analysis. For the numerical verification of the proposed analysis, U-bending simulations were carried out for sandwich plates with various inner structures including a pyramidal truss core, a honeycomb core, corrugated cores, and a sheared dimple core. The analytic scheme has enabled the acceptable prediction of the load curves and deformed shapes during U-bending.