Combined shape and sizing optimization of truss structures

 In this paper, an evolutionary optimization method is presented for weight minimum problem of a 3-dimensional truss structure in terms of nodal coordinates and element cross-sectional areas. The structure is subject to stress, local buckling and displacement constraints. Two types of design variables with different natures are optimized separately: (1) a fully stressed design (FSD) and scaling techniques are applied to sizing variables and (2) the evolutionary node shift method is applied to shape variables. Alternating procedure is utilized to couple the two types of variables and to combine the results. The optimum solution is achieved gradually from the initial configuration design. Two typical truss structures are examined to illustrate the validity of the method. Received: 22 October 2001 / Accepted: 04 June 2002 This research work is supported by the National Natural Science Foundation of China under the guarantees no. 10072050 and 10172072, respectively.     

桁架结构计算方法探讨

笔者在深入研究了桁架结构的经典计算方法之后,提出了一种新的计算方法——“轴力系数趋势平衡法”.这一方法不用力的投影平衡方程而使用了轴力系数的“趋势平衡”方程进行计算,从而在许多情况下使繁锁的桁架计算变得异常简捷。文中推导了方程,叙述了基本原理与方法,并通过例题证明了该方法的正确性与优越性。     

系统失效的分支-界限分析法及其在桁架可靠性分析中的应用

本文首先介绍了系统失效的分支-界限分析法，然后以空间桁架系统为例用分支-界限分析法进行了可靠性分析。系统失效的分支-界限分析法直观、明了，适合对实际工程中的复杂系统进行可靠性分析。     

Topology optimization of structures with integral compliant mechanisms for mid-frequency response

The purpose of this paper is to present a method for developing new truss-like sandwich structures that exhibit desirable mid-frequency vibratory characteristics. Specifically, a genetic algorithm optimization routine is used to determine candidate small scale structural topologies, i.e. unit cells, that may be used in the design of larger scale periodic sandwich structures. This multi-scale procedure is demonstrated starting with several unit cell topology optimization examples. From these examples a specific optimal unit cell is selected for further investigation and integration into a periodic sandwich beam. Computational results indicate that the proposed optimization approach is effective when used to design new structures for reduced mid-frequency vibratory response.     

一种三维刚架—桁架静力分析有限元程序

介绍了三维刚架计算原理以及作者所编制的一种应用于ＰＣ微机的有限元程序．本程序用＂ＦＯＲＴＲＡＮ＂语言编写,采用半动态一维存储．引入了单元整体形函数矩阵,简化了单元非结点载荷与结点载荷的转换过程．可用于计算三维及二维刚架或桁架在多种载荷条件下的位移及杆端内力并可绘出结构的有限元模型、支承、受载及变形状况．通过一系列算例验证了程序的正确性．     

Chaotic swarming of particles: A new method for size optimization of truss structures

A new combination of swarm intelligence and chaos theory is presented for optimal design of truss structures. Here the tendency to form swarms appearing in many different organisms and chaos theory has been the source of inspiration, and the algorithm is called chaotic swarming of particles (CSP). This method is a kind of multi-phase optimization technique which employs chaos theory in two phases, in the first phase it controls the parameter values of the particle swarm optimization (CPVPSO) and the second phase is utilized for local search (CLSPSO). Some truss structures are optimized using the CSP algorithm, and the results are compared to those of the other meta-heuristic algorithms showing the effectiveness of the new method.     

基于改进型蚁群算法的结构优化设计

结构优化设计中通常含有离散设计变量,本文探讨了如何将改进型蚁群算法应用于含离散设计变量的结构优化问题。以十杆桁架结构离散设计变量优化问题为例进行仿真,仿真结果表明蚁群算法能比较有效地解决含离散设计变量的优化问题。     

延性交错桁架体系抗震设计方法探讨

钢交错桁架结构体系[1]采用平面桁架体系,抗侧刚度高、自重轻、施工快速、造价低廉、绿色环保。近年来,备受国内外工程界及学术界的关注。该体系用平面桁架体系取代剪力墙,虽然大大节省材料,但腹杆的破坏导致结构突然的坍塌使其延性受到很大限制。基于上述原因,参考国外相关规范,笔者给出了该体系的一种延性设计方法,按照新方法进行设计可明显提高结构延性。     

AutoCAD ActiveX在圆管带式输送机弯曲段桁架的设计应用

系统地总结分析了圆管带式输送机线路布置的弯曲形式,并着重讨论了利用AutoCAD ActiveX技术来完成转弯段六边形托辊组桁架的设计。