松弛法

Four-node degenerated shell element and rigid shell element are used in our FEM model.Updated Lagrange formulation and rate form constitutive equation are adopted to solve the problem of large strain and large rotation in sheet forming process.Sheet metal material property is described by plastic anisotropy yielding model and isotropic hardening model.Master surface-slave surface contact model is used to define the contact between tools and blank.Contact constraints are enforced with a kinematic algorithm and friction stress is computed by Coulomb friction law.Dynamic relaxation method is used to treat springback after forming stroke.

四结点蜕化壳单元和刚体壳单元分别用来建立板和模具的有限元模型；更新Lagrange法和速率型本构关系被用来处理板料变形中的大应变和大转动；材料模型采用塑性各向异性屈服与等向强化模型；通过主从面模型定义板料和模具的接触，接触算法采用运动约束法，摩擦力用库仓定律计算；并利用动力松弛法对回弹过程进行了计算。

Parameters simplification of dynamic relaxation method is an improvement of the traditional method, and the increment of iteration is so small that this promoted method is worthy of further studying.

参数简化的动力松弛法是对传统动力松弛法的改进，而计算迭代次数比原来提高不多，因此，本方法值得尝试与进一步研究改进。

The comparision between adaptive multiple grid method and successive overrelaxation method［J］.

欧阳洁。自适应多重网格法与超松弛法的比较［J］。

This paper systematically reviewed dynamic relaxation method, force density method and nonlinear finite element method.

本文系统的回顾和研究了动力松弛法、力密度法和非线性有限元法。

Many methods are presented about form-finding of membrane structure, such as Force Density method, Dynamic Relaxation method.

找形分析目前国内外学者已经提出了不少方法，如力密度法、动力松弛法等。

In this paper, we have deduced an iterative algorithm with relaxation parameter from the successive over relaxation method, which not only deduce the necessary of computation time and memory space but also is propitious to overcome the sensitivity of reconstructed images to incomplete noisy data.

从解大型线性方程组出发，由逐次超松弛法(Successive Over Relaxation， SOR)推导出一种带有松弛因子的迭代法。与 SOR 法相比，该算法不仅大大降低了对计算时间和内存空间的需要，而且有利于克服重建图像对不完全噪声数据的敏感性。

This paper proposes a network parallel computing approach for hydromechanical problem on rectangle domain using line-relaxation method.A multigrid method with virtual nodes for the second kind boundary condition and a parallel scheme of zebra-line-relaxation multigrid technique are discussed.

提出了一个用线松弛法解决长矩形区域流场问题的网络并行方案，详细讨论了使用虚拟节点处理第2类边值条件的多重网格技术和斑马线松弛多重网格技术的并行化方法，给出了从计算方法到它的并行化的完整过程。

Take DMSO swollen treatment and DEA-SO2-DMSO decrystallization treatment for example, the X-ray diffraction and the Tobolsky's intermittent stress relaxation of treated woods were determined during soaking in water, analyzed the effects of water on crystal degree and inter-cohesion of treated woods. According to these continuous relaxation curves measured in water with different temperatures, various thermodynamic quantities were obtained by using Eyring absolute rate theory, and reviewed the chemical reactions in wood which occur in different relaxation process. For the first time quantify these crosslinkings formed in the process of tensional relaxation by using the SMCIR intermittent stress relaxation way, and defined the cross-linking reaction types. In order to find out the contribute of drying to the fixation of deformation of chemically treated wood, stress relaxation of oven-dry untreated and treated wood was measured during the process of temperature elevation and descend, then analyzed the effect of temperature change on relaxation mechanism of treated oven-dry wood. According to continuous relaxation curves of oven-dry treated wood under various constant temperature, calculated the thermodynamics of relaxation process and discussed the mechanism of molecule change in wood, at the same time, also quantified these cross-linkings produced in wood by intermittent method and on the basis of which the model of molecular change during relaxation process of chemically treated was constructed.

以DMSO膨胀处理及DEA- SO2-DMSO非晶化塑化处理为例，测定了两种处理木材在水浸渍过程中的X射线衍射及Tobolsky间歇应力松弛，分析了水对处理木材结晶度及内部凝聚力的影响；通过未处理和两种处理木材在不同温度水中的连续应力松弛测定，应用Eyring的绝对速度反应理论计算并获得了松弛过程中的各热力学量，分析了在水中松弛过程中不同阶段木材内部发生的化学反应；并首次采用SMCIR连续·不连续双曲线应力松弛法定量了轴向拉伸应力松弛过程中木材内部产生的架桥量，明确了交联反应的类型；为了了解干燥对处理木材塑性变形固定的影响，测定了未处理和两种处理绝干木材在温度下降过程和上升过程中的应力松弛，分析了温度变化对处理绝干木材应力松弛的影响；根据多个温度水平下的连续应力松弛测定曲线，计算松弛过程的热力学量，考察了绝干木材在松弛过程中内部发生的分子变化机理，同时也用间歇法定量了木材内部新形成的架桥量，并在此基础上构筑处理木材在松弛过程中内部分子构造的变化模型。

At last, natural frequencies of practical pre-stressed composite space truss are tested with pulsatory method on construction site and its damping ratio is calculated, which gives another important data for engineering design. In addition, through the model experiment of pre-stressed rectangular square pyramid composite space truss, the correctness of characteristics of internal force and the feasibility of tension recovery method are proved.

最后，在工程施工现场用脉动法测试自振频率，并借助于振动衰减曲线和半功率点法计算出预应力组合网架——钢与混凝土的混合结构体系——的阻尼比，此又为工程设计提供了一理论依据；另外，通过正放四角锥预应力组合网架的模型试验，验证了结构内力分布特点的正确性以及张力松弛法的可行性。

For form - finding of membrane structures , the common methods mainly indued three theory : nonliner fem , dynamic relaxation method and force density method

对于索膜找形分析，目前普遍常用的是非线形有限元法、动力松弛法和力密度法。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了