A Numerical Simulation Of Nonlinear Analysis With The Pull-out Experiments Of Sandwich Structure

For the aircraft structure, there are some thin components on which the load are relatively small, it is common to use the sandwich structure. It is widely used in the front edge of aircraft wings, airfoil trailing edge, wing control surfaces, and the trailing edge control surface as well as the doors of the aircraft. We need to install a lot of equipments on the sandwich board, so we should buried the inserts into the sandwich. The insert and the sandwich are gummed by the adhesive. The inserts are part of removable fixtures which is used for the connection of the sandwich structure and other parts of the fixed structure. In the past we mainly refer inserts as honeycomb sandwich structure or the structure of metal panel embedded parts. In recent years, the strength of the new foam structure is improved at or near the strength level of the honeycomb material. So it is possible to use the foam which has comprehensive performance in the sandwich structure.This article give a research about the failure mechanism of the honeycomb sandwich with inserts which is based on the experiments of the posterior edge of bush. In the research we discuss the failure criteria of the laminates of the sandwich structure and propose the idea to mix failure criteria to use in the structure. On this basis, we use foam sandwich instead of original honeycomb structure sandwich and make finite element analysis. We defined our own failure criteria and make program by use of UMAT then incorporated it into the material, so it is possible to make progressive damage analysis in this procedure. The delamination is simulated based on interface element with damage initiation criteria and damage evolution criteria. We consider the influence of the potting and discuss the way the potting material and the diameter of the potting influence the pull-out load.This article discuss about the pull-off load of the rivets of the plane empennage and make numerical simulation of them. It propose that the influence of the shape, size as well as the thickness of the panel when the rivet is made by the same material. It finally propose the pull-out principle of the rivet.