铁中Ⅰ型裂纹裂尖场的有限元模拟与形变分析  

Finite Element Method to Simulate Anisotropic Property at the Crack Tip in bcc iron

作　　者：刘磊[1] 郭雅芳[1] 

机构地区：[1]北京交通大学工程力学所,北京100044

出　　处：《科学技术与工程》2008年第8期2158-2162,共5页Science Technology and Engineering

摘　　要：以体心立方铁紧凑拉伸试样为研究对象,用有限元模拟计算了{100}<110>、{110}<110>、{111}<110>3种Ⅰ型裂纹裂尖应力场。3种不同的裂纹取向将体心立方铁的刚度矩阵转化为不同形式,导致裂尖应力场的不同·研究表明,{110}<110>和{100}<110>裂纹裂尖应力场沿裂纹张开面呈对称分布,与将材料假设为各向同性时裂尖场分布相似;而{111}<110>裂纹裂尖场在裂纹面上下呈不对称分布。这种裂尖场分布的不对称性也是导致裂纹扩展过程中裂尖微结构演化多样性的原因。Three types of mode Ⅰ crack in bcc Fe are selected to study the crack tip stress fields by finite element method, including types of { 100 } 〈 110 〉, { 110 } 〈 110 〉 and { 111 } 〈 110 〉 cracks. The stiffness matrixes are transformed according to different crack orientations. It makes the stress fields at the crack tip different. The research results have shown that the stress fields of{ 100 } 〈 110 〉 and{ 110 } 〈 110 〉 cracks are symmetrical for the crack plane, which are similar with the result of isotropic model. However, the stress field of { 111 } 〈 110 〉 crack is asymmetrical. It is closely related with the completed deformation behavior at the crack tip.

关 键 词：各向异性 有限元 裂纹扩展 

分 类 号：O346[理学—固体力学]