Model B-I for marco rectangular element is presented for the first time in this paper. To establish the influence surf ace for resultant R of bending plates, a number of generalized distributive loads q are defined. I...Model B-I for marco rectangular element is presented for the first time in this paper. To establish the influence surf ace for resultant R of bending plates, a number of generalized distributive loads q are defined. It is shown by numerical examples that Model B-I and the formula for the generalized distributive loads advanced in this paper are featured by high accuracy, low memory space and flexibility in practical application, and that they are especially effective for plate structures subject to moving loads, such as the two-dimensional continuous plates of highway bridges and the flat stabs in piled jetty engineering.展开更多
剪切型断裂是岩土工程中常见的破坏模式,了解剪切破坏机理并准确预测剪切型裂纹的萌生、扩展过程对保障工程结构的安全性与稳定性具有重要意义.文章建立了基于比例边界有限元法(scaled boundary finite element methods,SBFEM)和非局部...剪切型断裂是岩土工程中常见的破坏模式,了解剪切破坏机理并准确预测剪切型裂纹的萌生、扩展过程对保障工程结构的安全性与稳定性具有重要意义.文章建立了基于比例边界有限元法(scaled boundary finite element methods,SBFEM)和非局部宏-微观损伤模型的剪切型裂纹动态开裂模拟方法,定义了基于偏应变概念的物质点对的正伸长量,可作为预测剪切型裂纹扩展行为的动态开裂准则,一点的损伤定义为该点影响域范围内连接的物质键损伤的加权平均值,而物质键的损伤则与基于偏应变概念的物质点对的正伸长量相关联,并引入能量退化函数建立结构域几何拓扑损伤与能量损失之间的关系,将拓扑损伤与应力应变联系起来,通过能量退化函数修正了SBFEM的刚度系数矩阵,得到了子域在损伤状态下的刚度矩阵,推导了考虑结构损伤的SBFEM动力控制方程,采用Newmark隐式算法对控制方程进行时间离散.最后,通过3个典型算例验证了建议的模型可较好地模拟剪切型断裂问题,能够很好地捕捉剪切型裂纹的扩展路径,并得到较为准确的载荷-位移曲线.展开更多
论文建立了基于比例边界有限元法(scaled boundary finite element methods,SBFEM)框架的非局部宏微观损伤模型,考虑材料细观物理参数的空间变异性,探讨了材料参数的空间变异性对结构开裂过程的影响。结果表明:考虑材料参数空间变异性后...论文建立了基于比例边界有限元法(scaled boundary finite element methods,SBFEM)框架的非局部宏微观损伤模型,考虑材料细观物理参数的空间变异性,探讨了材料参数的空间变异性对结构开裂过程的影响。结果表明:考虑材料参数空间变异性后,裂纹扩展路径具有不确定性,建议的模型能够很好地反应材料内在的随机性;随着结构受力情况的复杂化和结构本体缺陷的增多,裂纹开裂模式的变异性也会增大。自相关长度和参数变异系数对结构开裂分析结果有重要影响。展开更多
文摘Model B-I for marco rectangular element is presented for the first time in this paper. To establish the influence surf ace for resultant R of bending plates, a number of generalized distributive loads q are defined. It is shown by numerical examples that Model B-I and the formula for the generalized distributive loads advanced in this paper are featured by high accuracy, low memory space and flexibility in practical application, and that they are especially effective for plate structures subject to moving loads, such as the two-dimensional continuous plates of highway bridges and the flat stabs in piled jetty engineering.
文摘剪切型断裂是岩土工程中常见的破坏模式,了解剪切破坏机理并准确预测剪切型裂纹的萌生、扩展过程对保障工程结构的安全性与稳定性具有重要意义.文章建立了基于比例边界有限元法(scaled boundary finite element methods,SBFEM)和非局部宏-微观损伤模型的剪切型裂纹动态开裂模拟方法,定义了基于偏应变概念的物质点对的正伸长量,可作为预测剪切型裂纹扩展行为的动态开裂准则,一点的损伤定义为该点影响域范围内连接的物质键损伤的加权平均值,而物质键的损伤则与基于偏应变概念的物质点对的正伸长量相关联,并引入能量退化函数建立结构域几何拓扑损伤与能量损失之间的关系,将拓扑损伤与应力应变联系起来,通过能量退化函数修正了SBFEM的刚度系数矩阵,得到了子域在损伤状态下的刚度矩阵,推导了考虑结构损伤的SBFEM动力控制方程,采用Newmark隐式算法对控制方程进行时间离散.最后,通过3个典型算例验证了建议的模型可较好地模拟剪切型断裂问题,能够很好地捕捉剪切型裂纹的扩展路径,并得到较为准确的载荷-位移曲线.
文摘论文建立了基于比例边界有限元法(scaled boundary finite element methods,SBFEM)框架的非局部宏微观损伤模型,考虑材料细观物理参数的空间变异性,探讨了材料参数的空间变异性对结构开裂过程的影响。结果表明:考虑材料参数空间变异性后,裂纹扩展路径具有不确定性,建议的模型能够很好地反应材料内在的随机性;随着结构受力情况的复杂化和结构本体缺陷的增多,裂纹开裂模式的变异性也会增大。自相关长度和参数变异系数对结构开裂分析结果有重要影响。
