应力函数

By means of plane elastic complex variable method and the theory of boundary value problems for analytic function, the stress distribution of elastic body is given in closed forms.

本文研究集中力作用下带任意孔洞的各向同性半平面焊接问题，利用复变函数方法和解析函数边值问题的理论，给出了弹性体应力分布封闭形式的解。

A modefied egg function has been proposed and used in a bounding surface model. This model has potential value of applicaton since it reflects better actual situation of soil mass under loading. That is: when a stress point is still within the yield surface, the unrccovered plastic deformation would occur as stresses change, and using closed smooth function makes stress modification in the FEM much easier.

文中提出了一个改进蛋形函数，并采用这个函数建立了边界面模型，该模型由于机理上更好地反映了土体受荷时的实际情况，即当应力点在屈服面内时，随着应力状态的改变，仍然可以产生不可恢复的塑性变形，而在计算功能上由于使用了封闭光滑的边界面，不存在角点问题使有限元程序计算显得很方便，从这两个方面看，该模型具有潜在的应用价值。

Based on the ICMmethod,the discrete topological optimization problem about spot-weld's existence or not is transformed into the continuous optimization problem on[0,1].The optimization model is founded with maximizing the structural stiffness as objective and structural strength as constraints.The problem of multi-objectives and multi-constraints is transformed into the problem of single-objective and single-constraint with the K-S function.The displacement and stress are transformed into the explicit function of design variables with the Response Surface Methodology.The optimization model is solved with Sequential Quadratic Program.

基于ICM（Independent Continuous Mapping，即独立、连续、映射）方法，将焊点有无的离散拓扑优化问题转化为[0，1]区间上的连续优化问题；建立了以结构刚度最大为目标、结构强度为约束的连续拓扑优化模型；采用K-S函数将多目标和多约束问题转化为单目标和单约束问题；运用响应面方法将位移和应力转化为设计变量的显式函数，采用序列二次规划方法求解优化模型。

Therefore, in this paper, a newempirical creep model is proposed, in which the power function is used for shear stress-strain behavior and hyperbolic function is used forstrain-time behavior.

鉴于此，本文试图建立新的蠕变本构模型进行理论分析，即应力-应变关系采用幂函数，应变-时间关系采用双曲线函数。

By using regression analysis method the reduced relaxation and creep functions were acquired.

用回归分析的方法处理实验数据，得出了归一化应力松驰函数、蠕变函数及曲线。

Firstly, the normal stress distribution over the 3D slip surface is initially assumed, which is modified by a function with five parameters involved for the rigorous solution, or by a function with four parameters involved for the quasi-rigorous solution.

假定空间滑面上正应力初始分布，对于严格解，用含5个参数的修正函数对其修正；对于准严格解，则采用含4个参数的修正函数。

Therefore, the application of the Ritz method is extremely restricted on this aspect.

对于平面应力问题，要求解的方程组如下 E 2u 1 2u 1+ 2v ∫∫1 2 x2 + 2 y2 + 2 xy + X umdxdy= 0 E 2v 1 2v 1+ 2u ∫∫1 2 y2 + 2 x2 + 2 xy +Yvmdxdy= 0 瑞次法的要点是要找到满足全部边界条件的位移函数，而这种函数一般仍然难以找到，尤其在边界不规整的情况下。

Draft gear is used to reduce the bump between the vehicles when the train runs or shunts, whose form of load is mainly impact load, and as for viscoelastic material such as the rubber, whose stress is not only relate to strain but also relate to the time, so under the action of impact load, the viscoelastic material's capabilities is very different from the common elastic material.

由于缓冲器是用于缓和列车运行及调车作业时车辆之间的冲撞，其所受载荷形式主要是冲击载荷，而对于橡胶这种粘弹性材料来说，由于其应力不仅是应变的函数，还是时间历程的函数，所以在受冲击载荷作用下的特性和普通的弹性材料的特性有很大的不同。

At last, the fundamental viscoelastic parameters are calculated according to the data of the electrostatic experiment and a three-element solid inversion model. Draft gear is used to reduce the bump between the vehicles when the train runs or shunts, whose form of load is mainly impact load, and as for viscoelastic material such as the rubber, whose stress is not only relate to strain but also relate to the time, so under the action of impact load, the viscoelastic material's capabilities is very different from the common elastic material.

由于缓冲器是用于缓和列车运行及调车作业时车辆之间的冲撞，其所受载荷形式主要是冲击载荷，而对于橡胶这种粘弹性材料来说，由于其应力不仅是应变的函数，还是时间历程的函数，所以在受冲击载荷作用下的特性和普通的弹性材料的特性有很大的不同。

Changing formula forms of single-shear, twin-shear and three-shear yield strength criteria, show that many of yield strength criteria of rock and soil materials can be expressed by the τ8 = gf function forms unter the ordinary condition, and that the main differ ences of yield strength value will mainly forcus on the different function forms of gθσ among single-shear, twin-shear and three-shear yield strength criteria.

对岩土体常用的单剪屈服强度准则、双剪屈服强度准则和三剪屈服强度准则进行了系统的论述，通过对单剪、双剪和三剪屈服强度准则进行转化，指出岩土的屈服强度准则一般可表达为τ8=gf的函数形式，阐明了单剪、双剪和三剪屈服强度准则的差异主要表现在g函数的不同，并进一步解释了中间主应力σ2对岩土类材料屈服强度的影响。

Objective: To study the effect of polycythemia on blood oxygen saturation.

裴蕾目的：观察RBC剧增而引起的高粘血症对血氧饱和度的影响。

Based on SIMPLER algorithm in the curvilinear body-fitted coordinates, the calculations were performed for Pr=0.7, Re=10~1000 on non-orthogonal non-staggered grids which are generated by elliptic equation systems.

采用曲线坐标系下压力与速度耦合的SIMPLER算法，数值研究了周期性渐扩渐缩波纹通道内脉动流动与换热情况，流动Re数的范围为10~1000，Pr数为0.7。