Four-step 3d Braided Composites Mechanical Properties Of The Finite Element Analysis

This paper poses a new unit model. At the same time,the mechanics performance of braided composites isanalyzed by using finite element method.This paper presents a method of describing yarnstructure of braided perform and obtains the movementrule of braiding yarns. In the braiding procedure, Thebraiding yarn is carried by the carrier and tends to movealong the direction of the carrier trace. In this paper,the least squares approximation method is introduced topredict the trend line of carrier movement. Then the yarnpaths are analyzed systematically. Finally, the threekinds of unit cell, the interior cell, the surface celland the corner cell, are established. They are orientedin the same reference frame as the preform. This paperestablishes the relations between braided parameters andgeometry parameters and it is valid by experiments.On the basis of geometry model mentioned above, thispaper establishes the finite element analysis model andcalculates the numerical value to predict the elastic modulus. By using common finite element method, it isdifficult to analysis the cell that includes both matrixand fiber bundle. the cell exists the interface betweenthe matrix and fiber bundle. hence, this paper poses anew scattered unit model--microstructure cell, arelatively coarse global mesh is applied to divide thethree_dimensional (3D) braided composite. then themicrostructure cell is analyze. Based on the structurecell model, this paper idealizes the cuboid cel1 as thereinforced musc1e cel1 that includes a isotropi c elast icmatrix material and di fferent oriented fiber materialthat has sing1e axia1 stiffness. The stiffness matrix ofreinforced musc1e is educed. Under the given boundarycondi tions, the elastic performance is calculated. Thecorrespond sQ\ftware is worked out that can predict: theelastic modulus quickly and timely by inputing thecorrespond brai ded parameters. The predi cted result s areidentica1 with experiment results. Al1 of those provesthe valid of modu1us prediction of 3D braided composi te.