数值计算

The development and research progress of ground deformation induced by pipe jacking construction was reviewed in the paper.

对顶管施工引起的地面变形计算方法的发展概况及研究进展进行了分析，把地面变形计算方法归纳为现场监测方法、数值计算方法、理论方法和实例数据分析法，并进行了比较，以更好地指导工程施工。

Methods for calculating the optimal solution of the minimum time attitude slewing motion and the energy-optimal problems were obtained using Genetic Algorithm, which does not need initial guesses and increases the calculational efficiency.

同时，将遗传算法引入卫星姿态控制的数值计算中，求解最短时间控制问题和能量最优控制问题，发展了一种新的最优控制问题的计算方法，避免了对迭代初值进行猜测的困难，提高了计算效率。

In the fifth chapter, the further derivation and demonstration of the VCA technique are made, and a new simple method to calculate the proper optimal step size in this condition is presented, which can improve the computational efficiency.

在第五章中，我们对VCA技术进行了进一步的更具一般性的推导论证，并在此基础上，推导出一种适用于该情况下的计算优化步长的公式，提高了数值计算效率，节省了计算时间。

So a method that combining the model experiment and numerical computation are discussed in this paper. The flow-induced vibration response of the plane recumbent gate in ShangHai qingshui river is computed in this method, and the result is reasonable and credibility, this method can be extend to compute the other hydraulic structures like overfall dam, guide wall, gate pier and so on, which is under fluctuating pressure.

由此探讨了一种将水力模型试验跟数值计算相结合来计算闸门流激响应具体值的方法，并应用于上海清水河泵闸水下卧倒门的流激响应计算上，结果合理可靠，该方法可以推广应用于溢流坝面、导墙、闸墩等受水流脉动荷载作用的其它水工建筑物。

Based on the above results, the problems of the electromagnetic interaction between a perfect conducting plate and 1-D/2-D conducting slightly random rough surface and the problems of the electromagnetic interaction between a dielectric spherical particle and dielectric slightly random rough surface are investigated. By using the reciprocity theorem, Small Perturbation Method and Physical Optics approximation, the solution for the composite scattering field from the composite target is derived and evaluated, and the numerical results are discussed and analyzed.

在此基础上，用互易性原理分别研究了一维、二维导体微粗糙面与其上方金属导体平板目标的复合电磁散射及介质粗糙面与其上方球形粒子的复合电磁散射，结合互易性原理和粗糙面散射微扰法及物理光学近似导出了复合散射场的计算公式并进行了数值计算，对计算结果进行了讨论和分析。

In chapter 4,on the basis of chapter 3,a new formulation of hybrid/mixedsingular plate element based on Reissner's plate theory is set up,and 4-node arbitraryquadrilateral hybrid/mixed singular bending plate element formulas including theeffects of transverse shear deformation is derived,then by the use of this method,alarge quantity of numerical computations are carried out,at the same time,the resultsare compared with theoretical solutions and the results obtained by other singularfinite element methods.

第四章 在第三章的基础之上，建立基于Reissner型板理论之上的杂交/混合奇异板单元列式，推导出了考虑剪切效应的四节点任意四边形杂交/混合奇异弯曲板单元公式，并进行了大量的数值计算，同时与理论解析解和其它有限元解进行了比较，计算结果表明：本文提出的杂交/混合奇异板单元方法是可以用于计算含裂纹平板弯曲应力强度因子的一种高效、可靠、简便易行的方法。

Taking into the feature of computer computing method, using Stress solution of elasticity theory and according to different method of solving of system of second order ordinary differential equations , this article provides two numerical value computing method as for the stress and deformation of the turbine impeller which is within the scope of elasticity .

从计算机计算的特点出发，采用应力法，根据二阶常微分方程组的不同解法，给出了透平机叶轮在弹性范围内应力和变形计算的两种数值计算方法。

It will consume lots of CPU time and hard disk space of computer in calculating the ultimate torsional moment of a hull girder by using FEM, especially for the complex structure. The ultimate torsional moment of box thin-walled beam is analyzed by using finite element method. The influences of different characteristic parameters on the ultimate torsional strength are extensively studied.

在船体梁扭转极限承载能力的有限元计算中，对於比较大而且形状复杂的结构，需要采用足够多的单元数来模拟其真实的破坏模态，因而会耗费大量的CPU计算时间和硬盘空间，并且往往因为单元数太多而使数值计算变得不现实。

Based on the constrained variation principle, the penalty function suited to electromagnetic field calculation is proposed in this dissertation. Detailed research is conducted on some problems, such as the selection of penalisation parameters, the effect of penalisation parameters to the CPU time and the accuracy of solutions.

本文基于变分原理构造了适合电磁场数值计算的罚函数，得到了系统的控制方程，并对罚因子的选取原则及罚因子对计算精度和计算时间的影响进行了深入研究。

In theory, firstly, the numerical simulation methods, such as the boundary element method, the finite difference method and the finite element method, were utilized to calculate the distribution of electric field intensity and potential of the electron-gun system, the focusing system and the whole equipment, respectively. Then, the trajectories of the electron-beam were traced by using of the Runge-Kutta method and the Monte-Carlo method associatively. The point spread function was also calculated.

在理论分析中，先后采用边界元方法、差分方法、有限元方法等科学数值计算方法，编制程序，对X射线源的电子枪发射系统、聚焦系统以及发射系统与聚焦系统的组合系统等的电场分布进行了严格的计算，在准确求得各系统电场内各个剖分点的电场场强、偏导数等参量的基础上，采用蒙特-卡罗模拟方法和不等距龙格-库塔方法相结合，追踪由LaB_6单晶阴极表面发射出的大量电子束在电场内的运动轨迹，求出点扩展函数，并根据点扩展函数的优劣，反复调节、大量计算对比，挑选出X射线源最佳的电极结构及其组合。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。