基于SBFEM计算劈拉试件裂纹尖端高阶奇异参数  

Calculation of higher order singular terms for crack tip of wedge-splitting specimen based on SBFEM

作　　者：刘钧玉[1,2] 徐凤琳[1] 宁宝宽[1] 

机构地区：[1]沈阳工业大学建筑工程学院,沈阳110870 [2]大连理工大学建设工程学部,辽宁大连116024

出　　处：《沈阳工业大学学报》2014年第3期347-354,共8页Journal of Shenyang University of Technology

基　　金：国家自然科学青年基金资助项目(51109134;11102118;51208310);中国博士后科学基金资助项目(2013T60283;2011M500557);辽宁省高等学校优秀人才支持计划资助项目(LJQ2011009);辽宁省教育厅基金资助项目(201344088)

摘　　要：比例边界有限元法是一种具有半解析性质的数值计算方法,径向位移和应力具有解析的性质,不需要特殊处理裂纹尖端,可以根据定义直接计算应力强度因子以及高阶奇异参数.为此基于比例边界有限元法计算了两种不同荷载作用下三种不同尺寸劈拉试件的奇异应力场,提取了T应力、高阶奇异参数以及应力强度因子.通过典型例题验证了SBFEM的有效性及其精度.数值计算结果表明,比例边界有限元法在计算应力强度因子、T应力和高阶奇异参数时是有效的,且具有较高的精度;联合子结构法(超单元)可以计算复杂形状问题的裂纹尖端奇异场.此外,T应力和高阶奇异参数可以作为进一步研究大体积混凝土材料和结构断裂性能的依据.The scaled boundary finite element method（ SBFEM） is a numerical method with half analytical nature. The displacement and stress in the radial direction exhibit the analytical nature,both stress intensity factors（ SIFs） and high order singular terms can be directly determined according to the definition,while no special crack tip treatment is necessary. Therefore, the singular stress field of three wedge-splitting specimens with different sizes and subjected to two different loads was computed based on the SBFEM,and the T-stress,higher order singular terms and SIFs were extracted. In addition,the effectiveness and accuracy of SBFEM were verified with the typical examples. The results of numerical calculation showthat for the computation of SIFs,T-stress and higher order singular terms,the SBFEM is efficient and exhibits higher accuracy. Furthermore,the singular field of crack tip with complex shape can be computed in combination with the sub-structure method（ or super-element）. Moreover,both T-stress and higher order singular terms can provide the basis for the further research on the fracture performances of concrete materials and structures with large volume.

关 键 词：应力强度因子 比例边界有限元法 T应力 高阶奇异参数 劈拉试件 裂纹尖端渐近场 应力奇异性 断裂力学 

分 类 号：TU528[建筑科学—建筑技术科学]