SOME PROBLEMS OF FEM MODELLING OF SANDWICH STRUCTURES

Abstract

Sandwiches are a form of composites providing high bending stiffness at a reasonable weight. This paper illustrates the possibility of calculating the stiffness of the sandwich structure (tram roof) with glued handles of roof equipment using FEM. Sandwiches can be modelled using different finite element types. The use of shell and solid elements is demonstrated on the example of three-point bending of sandwich beam. Another problem is the modelling of adhesive joints of individual sandwich parts or other connected structures. One possibility to model adhesive joints using FEM is the use of special cohesive elements. For a description of the mechanical behaviour of a relatively thin layer of adhesive is suitable definition traction – separation of interfaces. The above was used to calculate the stiffness of composite roof structure loaded through the handles of roof equipment.