Study And Optimization Of Bending Properties Of Plastic Honeycomb Sandwich Structure

The thermoplastic honeycomb sandwich structure studied in this paper is made of skin used GF/PP composites and honeycomb cores used PP.It is a lightweight structure that has excellent mechanical properties and is easy to recycle integrated.So it is very suitable for making vehicle's lightweight components,and easy to recycle.Due to the structural characteristics of the honeycomb sandwich panel,its most prominent performance is the bending performance.This paper will in-depth study of the plastic honeycomb sandwich structure's three-point bending process.Further the peak load and the specific energy absorption are multi-objectively optimized to lay the foundation for its application in automobile industry.(1)Through analyzing the test results of different honeycomb sandwich panels,it was found that the bending process of the honeycomb sandwich panels was mainly divided into two phases.The first phase was called the forward flexure phase.In this stage,the load increased approximately linearly.This stage is the normal range of using the honeycomb sandwich panel.The second phase was called the post-deflection phase.In this stage,the load drops rapidly to a certain load after reaching its peak,and it was continuously stable,forming a platform.At this stage,the honeycomb sandwich structure was destroyed and entered a continuous energy absorption stage.(2)The flexural performance of honeycomb sandwich structures with different geometries is studied through the three-point bending test.Several key parameters have been used to analyze the flexural performance of sandwich panels.The key factors involved are the ply method of skin,the thickness of skin,the orientation of honeycomb core,the aperture of honeycomb core,and the height of honeycomb core.The flexural performance were evaluated as peak load,average load,total energy absorption,and specific energy absorption.(3)Through summing up the failure modes of a variety of specifications of the sandwich plate,it was found that there were two major failure modes,respectively,failure mode A and failure mode B.From the macro analysis,it was found that the lamination of the sandwich plate and the thickness of the skin will affect the failure mode of sandwich panel.Combined with explicit finite element analysis technology,the reason for the occurrence of two kinds of failure modes is that the initial stress distribution on the honeycomb core is different,leading to different initial failure areas of the honeycomb core,thereby affecting the expansion of the failure,so there are two failure modes.(4)Through factor analysis,it was found that the thickness of cell wall,the diameter of cell,the height of honeycomb core,and the thickness of skin had a significant influence on the peak load and specific energy absorption.An approximate response model for the above variables and peak load was established by the response surface method,in the same way of specific energy absorption.The multi-objective optimization of the honeycomb sandwich structure was performed as a function of the peak load and specific energy absorption.It was found that there was no the minimum peak load and the biggest specific energy absorption.These two indexes could only be weighed according to actual needs.A set of Pareto optimal solutions is obtained by genetic algorithm,which provides reference for the design of honeycomb sandwich structure.Through research,the complete bending process of plastic honeycomb sandwich structure is analyzed in detail,which provides date support and theoretical support for its application in engineering.