二维机织复合材料弹性常数的有限元法预测

为了预测二维机织复合材料的弹性性能，建立了有限元力学分析模型。基于二维机织复合材料的几何特征，建立了参数化的单胞模型；考虑了织物纤维束呈现出的各向异性材料特征，将有限元中材料主方向转化到纤维屈曲方向，建立其力学分析有限元模型；分析了单胞边界面保持平面假设的不足，提出了对于二维机织复合材料通用的周期边界条件，获得了更为准确的二维机织复合材料的工程弹性常数。结果表明:织物衬垫单胞边界面，在单向拉伸载荷和纯剪切载荷下，呈凹凸翘曲变形，即为周期边界；应用给出的织物参数化几何建模方法与有限元求解方法，可以精确地获得工程弹性常数，数值计算结果与实验值吻合较好。 

Finite element prediction of elastic constants for 2D woven fabric composite

The finite element mechanical analysis model was established for the prediction of elastic properties of 2D woven fabric composite.Based on the geometrical features of 2D woven fabric composite,a parameterized unit cell model was established.The anisotropic material characteristics of the fiber bundles were considered,the principal direction of the material was converted to the direction of the fiber bundles buckling,and thus the finite element model for mechanical analysis was built.The insufficiency of the plane-keep-plane assumption for boundary surfaces of unit cell was analyzed and the universal periodic boundary conditions used for 2D woven fabric composite were proposed.Therefore,more accurate engineering elastic constants of 2D woven fabric composite were obtained.Re-sults indicate that boundary surfaces of unit cell of fabric liner present concave and convex buckling deformation un-der uniaxial tensile and pure shear load,namely that periodic boundary is demonstrated.Based on the fabric parame-terized geometric modeling method and finite element method presented,the engineering elastic constants can be ob-tained accurately,and the results of the numerical simulation are consistent with that of the experiment.