ABAQUS单元选择资料.ppt

Element Selection Criteria;内容提要;Elements in ABAQUS;Elements in ABAQUS;单元类型（Family） A family of finite elements is the broadest category used to classify elements. 同类型单元有很多相同的基本特。Elements in the same family share many basic features. 同种类单元又有很多变化：There are many variations within a family. ;Elements in ABAQUS;Elements in ABAQUS;公式Formulation The mathematical formulation used to describe the behavior of an element is another broad category that is used to classify elements. Examples of different element formulations: Plane strain 平面应变 Plane stress 平面应力 Hybrid elements 杂交单元 Incompatible-mode elements 非协调元 Small-strain shells 小应变壳元 Finite-strain shells 有限应变壳元 Thick shells 后壳 Thin shells 薄壳;积分Integration 单元的刚度和质量在单元内的采样点进行数值计算，这些采样点叫做“积分点” The stiffness and mass of an element are calculated numerically at sampling points called “integration points” within the element. 数值积分的算法影响单元的行为The numerical algorithm used to integrate these variables influences how an element behaves. ABAQUS包括完全积分和减缩积分。ABAQUS includes elements with both “full” and “reduced” integration.;Full integration:完全积分 The minimum integration order required for exact integration of the strain energy for an undistorted element with linear material properties. Reduced integration:简缩积分 The integration rule that is one order less than the full integration rule.;Elements in ABAQUS;Elements in ABAQUS;Structural Elements (Shells and Beams) vs. Continuum Elements;Structural Elements (Shells and Beams) vs. Continuum Elements;Shell elements Shell elements approximate a three-dimensional continuum with a surface model. 高效率的模拟面内弯曲Model bending and in-plane deformations efficiently. If a detailed analysis of a region is needed, a local three-dimensional continuum model can be included using multi-point constraints or submodeling. 如果需要三维实体单元模拟细节可以使用子模型 ;Structural Elements (Shells and Beams) vs. Continuum Elements;Modeling Bending Using Continuum Elements;Modeling Bending Using Continuum Elements;Modeling Bending