The Compression Failure Of Composite Honeycomb Sandwich Structure With Stringer Reinforcement

As an efficient lightweight structure, composite honeycomb sandwich panel has been widely used in many industries. In recent years, the increasing demand for high-performance, lightweight structures has stimulated a strong trend toward the development of refined models for sandwich structures. The composite honeycomb sandwich structure with stringer reinforcement is a new type of sandwich structure, among which several stringers are added in the honeycomb core to achieve a specific strength and stiffness, as well as to increase the reliability of the sandwich structure.The debonding defects of interface between the sheet and core often occur in manufacturing process for composite honeycomb sandwich structures. Moreover, the stringers laid in the sandwich structure will cause a geometric discontinuous of honeycomb core, as well as the discontinuous of load transfer, as a result, this local stress concentration will induce the structure easy to be damaged. For such new type of composite honeycomb sandwich structure, the failure modes and damage mechanism will behave some new forms. It is necessary to further research the damage mechanism and corresponding modeling and calculation method in numerical simulation for such complicate structure.This paper investigated the critical damage mode and failure behavior of composite honeycomb sandwich structure with stringer reinforcement under in-plane compression condition. The progressive damage of the composite sheet such as matrix cracking, fiber breakage and fiber/matrix damage were considered in the numerical simulation. The effects of stringer reinforcement on mechanical properties of composite honeycomb sandwich structure were revealed, and the parameter studies were carried out to analysis the effects of design parameters on structural properties. Besides, three different kinds of debonding damage of interface between sheets and core were considered, the failure modes and whole failure process of the new type sandwich structure with stringer reinforcement were obtained. This work was supported by project of National Basic Research Program of China (No.2014CB046506) and State Key Laboratory of Structural Analysis for Industrial Equipment.