查询词典 numerical calculation

This paper analyze and study the influence of the superimposition in depth based on the previous achievements and combined with the theoretical qualitative analysis and project instances. The main contents as follow:Chapter 1: Indicate the significance and objective of this paper, review the previous achievements of the transient process and superimposition, and then present the study purpose of this paper.Chapter 2: combined with the physic knowledge of the fluctuation and the superimposition, Indicate the physical essences and the influence of the superimposition phenomena that exist in the diversion pipe system, and take one hydraulic turbine owning only one diversion tunnel and two hydraulic turbines sharing one tailrace conduit for instance to study out the numerical calculation superimpose operations.Chapter 3: From the calculation theory of the parameter of the guaranty calculation of regulation of the hydro-turbine, qualitative analyze the influence of the superimposition on them and the superpose time, combined with some project instances, get the numerical value of the influence of the superimposition and the superpose time.Chapter 4: Based on the previous achievements of the calculation and theoretical analysis of the surge-chamber ground swell, analyze the influence of the superimposition on it and the superpose time.

本文在前人研究成果的基础上，结合理论定性分析及工程实例，对波动叠加带来的影响进行深入分析研究，其主要内容如下：第1章，指出本文研究的意义和目的，回顾前人对水电站过渡过程及波动叠加方面的有关研究成果，在此基础上提出本文的研究内容；第2章，结合物理学中有关振动与波动叠加方面的有关知识，阐述水电站引水发电系统中存在的波动现象的实质及其影响，并以两机一洞和一机一洞具有上游调压室或下游调压室的水电站拟定其数值计算叠加工况；第3章，从机组调保参数的理论出发，定性的分析波动叠加对机组调保参数的不利影响及叠加时间，结合几个工程实例，得到波动叠加带来的影响大小及叠加时间；第4章，在前人对调压室涌浪进行计算和理论分析的基础上，分析波动叠加对调压室涌浪的影响及其叠加时间。

Numerical calculation of FEM and experimental investigations are used in the present research. The influence of loading condition and size of indenter on the tensile strength of rock has been investigated. The results obtained by numerical calculation and experiments show that tensile strength of rock will increase with the increase of indenter size.

通过有限元数值计算与理论分析相结合的方法，对不同载荷接触条件和接触面宽度角下的岩石抗拉强度进行了深入分析，结果表明，在圆弧形和平台加载条件下计算的岩石抗拉强度随载荷接触宽度角α的增大而增大。

The 3-dimension solid model of the 8th turbine rotor blade of some type aero engine is constructed in software UG, and the numerical calculation region of stream field in ECM is set up in special flow field calculation software FLUENT based on the principle of hydrodynamics. The distribution of 6-dimension forces is got after numerical calculation, and the equation between 6-dimision forces and interelectrode gap is set up.

基于流体力学原理，用UG造型出某型航空发动机8级涡轮转子叶片，用流场计算软件FLUENT构造电解加工中叶片的流场计算区域，经数值计算得到六维力的分布，并从理论上建立六维力与间隙之间的关系方程式，为后续试验研究提供了参考依据。

But in the numerical calculation process, such as numerical differentiation, if we use these numerical methods inadequately, then it may be induced non necessary numerical error, including round off and truncation error.

因而常必须以值方法替代解析解，但是在值计算的过程中，很容引入额外的计算误差，包括舍位误差与截断误差。

Numerical Calculation of Applied Mathematics important branch of linear equations numerical calculation is an important part.

数值计算是应用数学的重要分支，线性方程组求解是数值计算中的一个重要部分。

This paper uses unsaturated soil Alonso elasto-plastic model to analyze the influence of model parameter value on numerical calculation. And the result shows that Finite Element numerical calculation which adopts the specimen integral deformation model parameter will generate errors, and overestimates unsaturated soil strength.

应用非饱和土Alonso弹塑性模型研究探讨了模型参数取值对非饱和土数值计算结果的影响，使用包含端部约束影响的试样整体变形确定的模型参数进行有限元数值计算将产生误差，同时也高估了非饱和土体的强度。

Some concepts about the reliability are described, and the method for calculating the reliability of system is provided by making linear substitution. While taking Stochastic Finite Element Method into the reliability calculation, a Nonlinear SFEM model is founded, and methods to resolve some problems in SFEM calculation are given. So as to the calculation of the force boundary, a method in FEM is provided for sabot pressure calculation, base of this, the numerical calculation model is carried out.

给出了弹丸发射强度可靠性计算中的一些理论和概念；给出了串联系统可靠性的逐步线性等效计算方法；将随机有限元方法引入可靠性计算中，建立了弹丸发射时的非线性随机有限元计算模型，并给出了计算中的一些问题的处理方法；在随机有限元的载荷边界的计算中，提出了弹带压力的有限元计算方法和在有限元求解思想上的数值计算模型。

By the numerical analysis of the ultimate bearing capacity of two- and three-dimensional footing under combined loading mode, the results show that the effect of alteration of underground water lever on bearing capacity of three-dimensional foundation is more than on that of two-dimensional foundation, the effect of soil gravity on bearing capacity of three-dimensional foundation is more than that of two-dimensional foundation. At the same time, the numerical calculation process of ABAQUS indicates that whether the geostatic stress is balanced or not has great effect on the numerical convergence. In view of the effect extent of dilation angle of soil on the ultimate bearing capacity and the failure pattern of foundation, the condition of two-dimensional plane strain is higher than that of the three-dimensional foundation.

复合加载模式下，通过对三维矩形基础和二维条形基础进行数值分析，结果表明：黏性土地基中地下水位的变化，对三维矩形基础极限承载力的影响程度高于对二维条形基础的影响；在求解地基极限承载力的过程中，土体重度对三维矩形基础的影响明显高于对二维条形基础的影响，同时ABAQUS数值计算过程表明，地基土体地应力能否合理平衡，对数值求解过程中是否收敛有很大的影响；就土体剪胀角对地基极限承载力的影响程度而言，二维平面应变情况下土体剪胀角对极限承载力的影响比三维情况下的影响更明显，即土体剪胀角对条形基础极限承载力的影响高于三维矩形基础。

The results of numerical analysis show that the elastic modular and the poisson ratio have no effect on two-dimensional bearing capacity, but can affect the ultimate bearing capacity of three-dimensional foundations and control the convergence and precision of finite element calculation; the earth pressure coefficient controls the geostatic stress of foundation, sequentially affects the ultimate bearing capacity of foundations and the convergence of numerical calculation. When calculating the ultimate bearing capacity of undrained saturated foundation, the complete formulation exists shear locking, and reduce formulation exists hourglassing, so the hybrid formulation is suitable to imitate the geomaterial. When the soil obeys nonrelevent flow rule, the yielding function is different from potential function, and the elastic-plastic matrix of soil is asymmetric, so the unsymmetry numerical solver and appropriate finite element mesh is required.

研究结果表明，土体弹性模量和泊松比对二维基础极限承载力没有影响，但是影响着三维矩形基础的极限承载力，控制着ABAQUS数值算法的计算精度与收敛速度；地基土压力系数控制着地基土体中的地应力平衡，从而影响着二维条形基础和三维矩形基础的极限承载力和地基破坏包络面；对于不排水饱和软黏土地基，常规的完全积分单元会造成剪力自锁现象，而减缩积分单元则存在过于柔化的现象，故采用杂交单元来模拟较合适；当土体服从非关联流动法则时，屈服函数与塑性势函数之间存在差异，从而导致土体弹塑性矩阵呈现非对称性，在有限元计算中必须采用非对称数值解法，并且合理地划分单元才能对极限承载力进行准确求解。

For the particular structure of water-lubricated plastic alloy bearings,with cannelures and low elastic modulus of plastic alloy bushes,and for the complicated numerical calculation of elastohydrodynamic lubrication,the multilevel method was introduced into the EHL numerical calculation of water-lubricated plastic alloy bearings,and the numerical results were attained successfully.

由于水润滑塑料合金轴承的特殊性：带有纵向的沟槽和轴承衬弹性模量低，以及弹流润滑的计算比较复杂，将多重网格法引入到水润滑塑料合金轴承的弹流润滑计算之中，成功地实现了数值解，为其理论研究奠定了基础。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。