In this paper, the space model for train carriages is developed and introduced in dynamic analysis fo train-bridge interaction. The rail irregularities described by the power spectral deusity functions are generated by inverse Fourier transformation, The equations of motion of train-bridge systems are derived and reduced to simulate the dynamic responses of bridges under moving trains. The Newmark's + integration method is adopted to solve the non-linear coupling equations. Numerical examples show that the method of this paper has high accuracy in simulating trainbridge interactive dynamjes.

The use of geodesic lines is a practical and economical method in the cutting process of textile structures. In this paper, methods for finding geodesic between two points are described. A new method based on FEM theory is proposed and equations are derived for finding the geodesic on discrete surfaces composed of triangles. Numerical examples show that the method of this paper is suitable for both developable and undevelopable surfaces, and is with high efficiency and high accuracy

基于可靠度的钢结构体系稳定设计理论，提出了通过抗力分项系数验算结构稳定性的方法，在确定分项系数时，考虑了结构的材料和几何初始缺陷，使用基于响应面函数的蒙特卡罗模拟方法对结构进行二阶弹塑性分析。通过3个典型算例，比较了此方法与现有稳定设计方法所得结果，分析了现有稳定设计方法在不同情况下的误差及其原因，明确了计算长度方法和二阶弹性分析方法的适用范围，验证了此方法的正确性。

根据有限元平衡方程推导了索体系机构运动的有限元求解方法。采用广义逆矩阵理论求解体系的通解和特解，分别解释了通解和特解的物理意义，分析了展开机构的理想形状及其实现途径。数值算例表明：有限元求解方法可以非常有效地跟踪求解索杆体系机构运动问题的全过程路径，得到机构运动的静定状态。与基于几何理论的现有机构展开分析方法相比，索杆体系机构展开的有限元求解方法具有大增量、高效率、收敛稳定、适用性广等优点。

推导的门式钢刚架的楔形单元是一个静动力空间力学计算模型，采用这一模型在设计计算门式钢刚架时对变截面楔形梁柱仅需采用一个两节点的单元的质量矩阵就可精确描述其工作特性。分析比较表明：所推导的计算模型具有很高的计算效率的精度。

建立了大跨悬臂预应力钢结构施工过程跟踪的数值分析模型，提出了在施工过程数值跟踪中对新增杆件节点定位、索段伸缩等问题的处理方法，介绍了施工过程数值跟踪的图形化模似途径和技术。经与实际工程现场测试结果比较，证明该方法具有较好的计算精度和很强的实用性。

This first author of thes paper is one of four winners fo the 2005 Hangai Prize, awarded for outstanding papers that are submitted for proemtaton and publication at the 2005 Hangai Prize, awarded for outstanding papers that are submitted for proaentation and publication at the annuai IASS Symposium by younger members of the association (under 30 yesrs old). It is republished here with the permission of the editors of the proceedings of the proceedings of the IASS 2005 Symposium on Shell and Spatial Structures-Theory, Technique, Valuation, Maintenance, held in September 2005 in Bucharest, Romania. This paper presents the structural design of Samoa Aquatic Center. Some curves are built to form the doublecurved surface of the roof. Furthermore. roof structure is composed of runthrough circular or rectangular hollow section steel tubes truss. The structure is analyzed in three-dimensional finite-element model. Through this way, some important data, such as displacement and vibrating period of structure, are obtained The mutual effect of steel roof and the supporting concrete frames is considered in this paper. The data which obtained respectively from 3D3S7.0 and Ansys 7.1 are compared. It can draw a conclusion that the structure is safe enough to fulfill its function of practical employment. In addition, several important joints are designed in detail. Practical application proves these joints are advantageous.

Compared with the wide application of the membrane structures, the pretension measuring techniques for membrane structures have developed far more slowly. Further studies to search for a high-precision pretension measuring method which is reliable in theory and convenient for operation are not only necessary but also urgent. With the help of the finite element method, two important characteristics, the principles of "Stress Superposition" and "Stiffening Effect of Stress", are discovered and summarized in this article. The characteristics relate to the relationships between the pretensions of a stretched rectangular membrane with fixed boundaries around, the out-plane displacements at the central point of the membrane and the normal uniform loads applied on the membrane. Based on these two characteristics, a new method to measure the pretensions of membrane structures is proposed, which is celled "Numerical Measurement" in this paper. In the final part of the paper, a series of experiments are reported to validate the correctness of the method. The comparisons between the results of the method and those of the experiments are carefully made, which show that the two groups of results agree with each other very well. The results of mumerical simulations and experiments prove that our method is a reliable method, and the measuring results are of high precision.

In this paper the dynamic amplification factors and the equivalent uniform distribution load (EUDL) of bridges under random traffic flows are analyzed. The simply supported beam is selected as the bridge model. Two types of road roughness: road with step surfaces and stochastic surfaces, are included in simulation. The plane truck model can be with simple lorry or double lorries with various random parameters. Both free and congested traffics in individual slow or fast lanes and two lanes are considered. The dynamic amplification factors and EUDL of bridges with some given span from Monte Carlo simulations are listed.

基于有限单元平衡方程推导了索杆体系机构运动的通解、特解及其路径跟踪的迭代求解列式，以及机构运动与弹性变形混合问题的迭代解列式。从机构运动和弹性变形问题的比较角度出发，解释了机构运动中的若干基本定义，对索杆体系的机构运动和弹性变形混合问题作了分类。数值算例表明：采用本文方法可以非常有效地跟踪求解索杆体系机构运动、弹性变形及其混合问题的全过程路径，得到机构运动的静定状态的混合问题的平衡状态。