3d Angle Interlock Finite Element Analysis Of Elastic Properties Of Structural Composites

On the base of Finite Element Method theory and that the composite's distortion is compatible when given loads, new geometry analysis models of 3D angle-interlock architecture reinforced composites were built up by CAD software, and then transformed into FEA software to evaluate their elastic properties. The comparison between FEA results, the measured ones and the averaging stiffness theoretic ones shows they follow the same tend, which means the FEA method is available for prediction of 3D angle-interlock architecture reinforced composites and the micro cell structure is correct. The effects of designing parameters were discussed.Four geometry models were built up by PRO/ENGINEER software, in which geometry parameters were related to perform design parameters. So new model was created by inputting preform design parameters, and the structure could be easily observed.In the FEA process, the effects of the least repeated element, the structure of cell model, the parameter H and the smart size degree were discussed, and then the suitable cell model was selected.Based on comparing FEA theory prediction values of equivalent engineering elastic constants and experiments data and the averaging stiffness theoretic prediction values, it is affirmed that the FEA method is available for prediction of 3D angle-interlock architecture reinforced composites.An analysis of the effects of preform design parameters indicates that the shapes of cross-section of weft (a_f), the fiber's properties and the yarn density affect prediction results so much. As the increasing of a_f, the fiber volume fraction of composites and equivalent engineering elastic constants almost increased linearly. The elastic property of composites will be stronger with fiber of the better axis property, and the difference between the weft equivalent elastic constants and the warp one, of the composite of isotropy fiber (E glass fiber), is slight. As the increasing of warp density, the fiber volume fraction and warp equivalent elastic constants almost increase linearly, but the weft equivalent elastic constants almost decrease linearly. As the increasing of weft density, the fiber volume fraction and weft equivalent elastic constants almost increase linearly; however, the warp equivalent elastic constants increase firstly and then decrease.