The Statics Analysis Of Cylindrical Composite Sandwich Structure

The cylindrical sandwich structure is widely used in several types of pipeline structures indifferent engineering fields due to its excellent mechanical properties. This article mainly discussesthe statics problems of cylindrical composite sandwich structure loaded symmetrically with respect toits axis in two different ways.The part one analyzes the cylindrical sandwich structure with orthotropic layers. Based on theknowledge of elasticity, physical equations, geometric equations and equilibrium equations are raisedand simplified into a differential equation of a certain stress function. Due to the continuousconditions of radial stress and displacement between layer and layer, also the load that act on theinside and outside boundary, a series of identified equations are built. Stress and displacement can besolved if stress function is determinate. Apart from these，this part also puts the sandwich structureinto the infinite elastic body, regard it as deep buried pipeline, and does the statics analysis.Furthermore, this article calculates the theoretical solutions and the finite element solutions fromANSYS and discusses the influence of different elasticity modulus of core. The result proves theconsistency of the solutions from two different ways.The part two fixes the one-order shear theory based on the sandwich plates and shells theoryraised by Reissner. It takes the plane stiffness of core layer into account, and discusses the staticsproblems of cylindrical sandwich shell with hard core and transverse shear. With the assumption ofdisplacement after deformation, this article derives the forces and equilibrium equations ofaxisymmetric form. Based on these equations, this article derives the analytical solutions ofcylindrical sandwich shells bending problem on the different boundary conditions, like submitted tothe action of bending moments and shearing forces uniformly distributed along the edge, loaduniformly distributed along a circular section, load distributed at a circular cross section and so on. Inaddition, this article discusses the influences of different factors, like transverse shear, elasticmodulus of the core layer,load length by some numerical examples.