论文部分内容阅读
利用二维有效应力和平均应力的描述方法,推导出三维横观各向同性泡沫材料在轴对称载荷下的特征平均应力、特征应力以及特征应变的表达式,得到用特征平均应力和特征应力描述的屈服面模型;并通过对面心立方单胞模型进行有限元分析,研究了横观各向同性泡沫材料的泡孔长径比对弹性性能和屈服面的影响.结果表明:随泡孔长径比的增加,泡孔伸长方向对应的泡沫模量增加,而与其垂直方向的泡沫模量则减小,且屈服面发生了逆时针转动;得到的屈服面模型与Gurson修正模型基本一致,且同有限元结果相符,为横观各向同性泡沫提供了一种新的屈服面描述.
Based on the description of two-dimensional effective stress and average stress, the characteristic average stress, characteristic stress and characteristic strain of three-dimensional transversely isotropic foam under axial symmetric load are deduced. The characteristic average stress and characteristic stress The yield-surface model of the transverse-isotropic cubic cell was studied by means of finite element analysis. The effects of the aspect ratio of the transversely isotropic foam on the elastic properties and yield surface were studied. The foam modulus corresponding to the direction of cell elongation increases while the foam modulus perpendicular to it decreases and the yield surface rotates anticlockwise. The yield surface model obtained is basically consistent with Gurson’s modified model In agreement with the finite element results, a new yield surface description of transversely isotropic foam is provided.