Механика машин, механизмов и материалов (Mar 2018)
Modeling of Elastic-Plastic Bending of Sandwich Panels with Thin Reinforced Bearing Layers
Abstract
In the framework of the deformational theory of plasticity and in a geometrically linear formulation, the problem of inelastic bending for sandwich panels with thin reinforced bearing layers is formulated. The weakened resistance of the core to the transverse shears on base of the kinematic hypothesis of straight normal when it is independent on the rotation is considered. The linearization of the problem by the method of variable elasticity parameters is carried out. In the case of cylindrical bending the elastic-plastic behavior of the rectangular elongated three-layer composite plates with a weak honeycomb core is investigated. The analysis of the dependence of compliance in the transverse direction of such structures on the parameters of the reinforcement of load-bearing layers is carried out. It is obtained that depending on the orientation of the cells of the honeycomb core relative to the normal to the supported edge of the sandwich panels, two different mechanisms of deformation can be realized: “classical”, when the bending state dominates and “non-classical”, when the dominant influence on the deflection has a transverse shear of the core. In the second case, in the vicinity of the supported edges the edge effects, which characterize cross-section of the three-layer structure in the transverse direction, are raised. It is discovered that for nonclassical mechanism of deformation the change of the deflection of sandwich panels is depended to a lesser extent on the varying parameters of reinforcement (angles and densities) of bearing layers than on the classical mechanism of deformation of this design. It is obtained that minimal compliance of the sandwich panels is achieved by such orientation of the cells of the honeycomb core, when classical mechanism of its deformation is realized.
