有限元法

To give the definition of the mass concrete and to concrete\'s cracks together with practical meanings of control ,and give a brief review on the research in the field at home and abroad, at last, methods to control temperature crack of the mass concrete from several aspects such as design measures,concrets material, construction schedules.etc are summed up; To explain the physical mechanics of the concrete and computing methods-Difference Method and Finite Element Method, and illustrate the application of their specific methods repectively;Several temperature factors that can influence the temperature stress of mass concrete baseplate are analyzed. The influence degree of temperature factor can be got through the ANSYS simulation computation the control of temperature can control the temperature stress, consequently control the temperature crack of mass concert baseplate; through the influence of the crack resistance ability of mass concrete baseplate which takes the reinforcement as a part is analyzed. By ANSYS simulation, the best suited volume ratio of reinforcement is found out, at same time the layout of reinforcement with the same volume ratio can also affect the resistance ability of mass concrete baseplate. Sum up of above analysis, anti-crack function of steel bar in early mass concrete baseplate is obvious, so it\'s necessary to consider beneficial effect of construction steel bar in research of temperature control on mass concrete baseplate.

本文先容了大体积混凝土及混凝土裂缝的基本概念，对国内外在这个领域里的研究现状作了扼要叙述，并从结构设计、混凝土材质、施工措施等方面总结了大体积混凝土温度裂缝控制的方法及防止措施；阐述了混凝土的基本物理力学性能，总结了大体积混凝土温度计算的方法——差分法和有限元法，并分别举例说明其具体应用的方法；分析了影响大体积混凝土底板温度应力的几种温度因素，利用ANSYS模拟计算，得出了每种因素的影响程度，通过分析提出了在这几种温度影响因素下如何通过控制温度以达到控制温度应力从而来控制裂缝的具体建议；针对大体积混凝土基础底板中配筋的不同对混凝土底板抗裂能力的影响不同，利用ANSYS进行模拟分析，得出底板中最合适的体积配筋率，同时分析了在相同体积配筋率下钢筋的具体布置对大体积混凝土基础底板抗裂能力的影响，分析表明，配置钢筋对混凝土结构的开裂阻止作用明显，在研究大体积混凝土温度裂缝题目时，要考虑钢筋在其中的有利作用。

The numerical methods in engineering such as FEM and BEM have been successfully used.

工程中的数值方法，如有限元法和边界元法等目前已取得了很大成功。

In this paper the magnetic distribution character of micro-electro-mechanical relay was analyzed by applying Biot-Savart law and integral equation method. The results of IEM and FEM show the method which used in analyzing three-dimensional stationary magnetic field for Micro-electro-mechanical relay is feasible.

文中应用毕奥-萨伐尔定律和积分方程法，分析了微机械电磁继电器磁场分布特性，计算结果与有限元法结果进行比较，表明所用方法对于微机械电磁继电器三维恒定磁场的分析是可行的。

Compared with Finite Element Method and Finite Difference Method, Boundary Integral Equation Method is computationally more efficient.

与有限元法和有限差分法相比，该方法具有更高的计算效率。

However,authors still do not find the relevant references on convergence and symmetric problems of the semi-analytical solution.Based on the semi-analytical solution for Hamilton canonical equation theory,the formulations of the clamp and simply supported and symmetric boundary conditions on the Hamiltonian element are derived by the variational principle.Several numerical examples show that with increase of meshes,the convergence rate of the semi-analytical solution is faster than the convergent rate of traditional finite element method based on displacement.

①在厚度上没有任何位移和应力模式的假设，由于传递矩阵方法的引入，从理论上讲，不受板壳厚度或层合板壳层数的限制；②采用弹性力学的Hamilton正则方程半解析法，可以克服边界的局部化效应[8]；③由于在平面内或圆柱壳的曲面内采用了有限元法，所以一般的板壳问题不受结构侧面边界条件的限制，在复杂工程板壳问题上具有广泛的应用领域。

The influence of free surface on tunnels is discussed.The influence of blasting vibration on fresh concrete lining is studied. The finite element method is employed to analyze the spatial distribution of temperature and thermal stress of fresh concrete lining, the wave function expansion method is used to study the interaction of blasting seismic wave and the circular tunnel with lining, thenthe safe PPV of fresh concrete lining with different age is decided by taking into account the thermal stress of concrete lining. Using the conformal mapping method, the influence of blasting vibration on the arch tunnel with lining is studied and the safe PPV of concrete lining is deduced under different incident angle.

研究了爆破振动对新浇混凝土衬砌的影响，采用有限元法求出了圆形洞室新浇混凝土衬砌内温度和温度应力在空间上的分布及其随时间的变化，采用波函数展开法求解了爆破地震波与有衬砌圆形洞室的相互作用，获得了考虑新浇混凝土衬砌内温度应力前提下不同龄期的新浇混凝土衬砌的安全振速；利用保角变换研究了爆破振动对直墙拱形有衬砌隧洞的影响，得到了爆破地震波以不同角度入射时混凝土衬砌的安全振速。

Slope; limit equilibrium method; the finite element method; clinometer; displacement; water level; efficiency rainfall; grey system; grey association

工程科技II，工业通用技术及设备，工程基础科学滑坡；极限平衡法；有限元法；测斜；位移；水位；有效降雨量；灰色系统；灰色关联度

Firstly establishing mechanical model of casing structure , and then processing casing forces analysis using space finite-element method and superposition method(put structure stress and outer force stress together), it computes the stress of casing in three dimensions, and gets the internal force and transmutation. The structure of casing-coadjutor is computed overlaply and the question of contact is solved. In the aspect of design, it provides the mixed integer-discrete variable optimization method of casing cross section size and coadjutor layout.

本文就上述两个问题的最优化设计展开研究，首先建立了套管结构的力学模型，进行套管的受力分析，用了空间有限元法和叠加法(结构应力和外载应力相叠加)，对套管进行三维计算，确定结构的内力和变形，对套管—扶正器结构进行整体的叠代计算，解决接触问题；在设计方面，提出了解决套管截面尺寸参数和扶正器布局的混合整数—离散变量优化方法。

Through comparison with finite element method, it has been demonstrated that boundary clement method is an effective method in the analysis of some complicatedly loaded parts and local stress concentration areas on loaders.

通过与有限元法比较表明，边界元法是分析装载机某些受力复杂零件和局部应力集中区域的有效分析工具。

The finite element method and indirect method were used to analyze the slot-teeth component of detent force in PMLSM at the outlet end.

采用有限元法及间接法对PMLSM的动子在出入端时的磁阻力的齿槽分量进行分析。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。