Analysis Of Mechanical Properties Of Variable Angle Fiber Placement Components

With the rapid development of the aerospace industry,the application of advanced composite materials is increasing.How to improve the structural properties of composite materials has become the focus of research in the industrial field.The continuous advancement of automatic placement technology makes it possible to lay out the curve of the fiber.Compared with the traditional straight-laid layup,the variable angle curve placement makes full use of the orientation of the composite,and greatly optimizes the structural properties of the composite material.In this paper,the variable angle curved layer paving member is taken as the research object,and the curved paving fiber laying path is designed to explore the influence of different path curve parameters on the mechanical properties of the curved surface components.The main work is divided into the following aspects:(1)Based on the Hermite curve,the reference path of the fiber curve placement is designed.Taking the 6th-order Bezier curve as the wire and the unidirectional axis as the straight busbar,the curved surface components is obtained.The curved surface is projected onto the plane and the reference path is designed on the projection plane.Combining with the classical method of constructing the complete layup isometric,the translation method and the parallel method are compared and analyzed.The reasons for the gaps and overlap of the layers are discussed.Based on the comprehensive analysis results,the translation method is used to construct the variable angle surface layer.According to the parameters affecting the path of the reference curve,the representation of the variable angle surface layering is determined.(2)The surface and the projection plane are discretized into a grid,and the curve placement paths are discretized on the projection plane to obtain a placement angle of each mesh fiber,and each grid is given a material property.Based on the idea of discrete layer modeling of variable angle surface components,combined with the development of ABAQUS secondary development interactive interface GUI plug-in,the process of GUI program development was determined,the corresponding Python code was written,and the plug-ins Surface_Statics for static analysis and Surface_Buckle for linear buckling analysis were developed.Plug-in development improves the efficiency of simulation experiments.(3)For the variable angle layer constructed in this paper,using the GUI plug-in developed in this paper,the static analysis of the variable angle layer component under the single-sided compression load is carried out,the stress and strain distribution cloud image is obtained,and the maximum and minimum stress strains are extracted.The analysis results are discussed along the direction of the wire and the straight busbar.The influence of the path parameters of different fiber curves on the stress and strain is explored.In each set of experiments,the maximum and minimum stress strains are compared,and the percentage of the corresponding mechanical properties and its application in engineering are given.By controlling the parameters of the fiber curve path,a composite curved surface layering member with better mechanical properties can be obtained.(4)The linear buckling analysis of the variable angle layer component under the uniaxial compression load is carried out,and the results of linear buckling analysis are obtained.The first-order linear buckling modes and eigenvalues are extracted and the first-order buckling loads are calculated.The first-order linear buckling mode is analyzed and it is found that the buckling mode changes greatly with the change of the fiber curve path,and the first-order buckling load is analyzed and the first-order buckling load is continuously changed with the change of the fiber path.The influence of the path parameters of different fiber curves on the first-order buckling is explored,and in each group of experiments,the first-order buckling loads are compared and the degree of improvement of the buckling load is obtained.Therefore,by adjusting the parameters of the fiber curve path,a composite curved surface layering member with better stability can be obtained..