The Performance Analysis And Strengthen Process Of Composite Corrugated Structures Under Flat Pressure And Shear Loading

The composite corrugated structures have excellent characteristics of light weight and high strength.They have been widely used in various industries of the world in recent years.The researchers have focused on improveing the bearing capacity of composite corrugated structures to satisfy the environment and cost in service.In this paper,the theory and experiment combined with simulation are used to analyze the flat pressure and shear response of composite corrugated plates with panel and core co-cure process.The foam filling and interfacial short fiber film strengthening are proposed according to the failure behavior of corrugated plates.This study is supported by the Fundamental Research Funds for the Central Universities(DUT18JC27),Natural Science Foundation of Liaoning Province(20170540161)and National Science Foundation in China(51790172).The first chapter introduced the research background of composite corrugated structures and the research statuses of the world.The main molding process of composite corrugated board and the main content of this paper were present.In the second chapter,the relative density of composite corrugated unit cell was given.The failure strength and modulus of composite corrugated plates subjected to flat pressure were theoretically derived.The different failure modes of composite corrugated plates under flat pressure were obtained..The core failure strength,shear modulus and panel/core debonding of the composite corrugated plates under shear loading were deduced.It was found that the interface debonding between the composite panel and the corrugated core was the main failure mode.In the third chapter,the failure modes of composite corrugated plates under flat pressure were predicted theoretically.Two kinds of different sizes and configurations of composite corrugated plates are subjected to flat pressure test.The numerical simulations of the two different failure modes-buckling and strength of composite corrugated plates were carried out to verify the theory prediction.Furthermore,according to the characteristics of failure behavior,a strengthen process method by using foam filling as a mold was proposed,and the superiority of this method was verified by experiments.In the fourth chapter,the shear experiment of the composite corrugated plates was carried out.According to the experimental phenomenon,the finite element model considered the panel/core adhesive layer was established.The method for determining the interface parameters of the adhesive layer was given.Furthermore,a strengthen process by adding Kevlar chopped fibers between the face/core was proposed to improve the shear resistance of the composite corrugated plates.The strengthening mechanism of the chopped fiber was discussed by the shear test and the surface observation after the interface debonding.The research results of this paper will provide beneficial theoretical and experimental results for the composite corrugated structures in the co-curing process,failure mechanism,simulation analysis and strengthen process.