杆系结构形态创构方法研究

发布时间：2018-10-12 07:29

【摘要】：结构形态创构是建筑与结构交叉领域新兴研究方向之一，是从结构分析出发，寻求多种“良好”建筑形状的理论方法，对建筑与结构设计的进一步发展有较深的意义。杆系结构类型众多，在实际工程中应用广泛，杆系结构形态创构方法的研究具有较高的应用价值，有助于建筑形式的多样化。本文以结构优化理论为基础，考虑建筑空间制约条件，以结构刚度最大化为设计目标，，提出了兼顾形状、拓扑和截面的杆系结构形态创构方法。方法中考虑了程序通用性，使方法能够用于各种杆系结构的形态创构。本文主要开展以下几个方面工作： 1.建立了杆系结构的节点调整方法从应变能和节点坐标的关系出发，推导了节点移动应变能敏感度表达式，并考虑空间制约条件，得到了受约束节点移动应变能敏感度表达式。详细分析了节点移动应变能敏感度的特性，提出了根据应变能对节点坐标的敏感程度逐步调整节点来实现结构刚度最大化的杆系结构形状创构方法。为了提高进化效率，进一步研究了节点移动方向的修正方法，对杆系结构形状创构方法进行了改进。研究发现在应该能收敛阶段，节点移动敏感度趋于零，此阶段的结构具有对初始缺陷不敏感的特点。 2.提出了兼顾拓扑和形状的杆系结构拓扑形态创构方法为了评价每个单元在整个结构中抵抗荷载的贡献程度，定义了单元增减应变能敏感度，并将其作为衡量单元承载效率高低的指标。利用单元增减应变能敏感度的特性，研究了单元增减的策略，并结合节点调整，提出了兼顾结构拓扑与形状的创构方法。该方法通过直接地消除低效单元和在高效单元附近增加单元，实现了结构的拓扑变化，并通过节点调整修正拓扑变化过程中的节点位置和结构形状。由于单元可增可减，方法的初始结构既可以简单也可复杂，可灵活选择。在结构形态确定后，在方法中还引入了截面优化，使方法可以兼顾形状、拓扑和截面，完善了方法。方法适用广泛，能够用于平面及空间中的各类杆系结构的形态创构。 3.在杆系结构形态创构方法中考虑了建筑空间制约条件为增强本文方法的实用性，采用B样条曲线（曲面）等来表达建筑要求所提出的空间制约条件，并在应变能敏感度的推导过程中给予反应，使方法所产生的结构能够满足建筑要求。此外，还利用初始结构对最终结构的影响，在初始结构确定时以不同的杆件布置手段来体现空间制约条件。由于初始结构是结构演化的起点，同时也为新杆件生成提供基本的可能空间，对建筑空间制约条件的实现起重要作用。还通过对不同应用场合下的空间制约条件的处理，增强了方法的实用性，同时也丰富了结构形态创构方法的内容。 4.研究方法在平面及空间结构中的应用为了探讨方法的适用性，对平面及空间结构中的桁架型结构，树状型结构，桥梁型结构等进行了大量算例应用实践。算例展现了方法广泛的适用性和实用性。针对不同支座条件，不同初始结构条件、不同创构策略以及不同结构类型的杆系结构进行形态创构。考察了进化过程中结构形态变化和力学性能变化，总结了创构策略对结构形态变化的影响和方法的特点。方法所得结构形式具有以轴力传递荷载的几何特征，结构形式多呈现优美的弧状，这有利于建筑造型中美学意图的实现。同时，所得结构形式符合力学概念，可为结构力学教育和结构设计提供参考。 5.研究并总结了方法所得结构的力学性能从大量算例的力学量的变化可知，兼顾拓扑与形状的杆系结构形态创构方法可以使结构向刚度提高、弯矩降低的方向演化，最终结构将以轴力为主要传递荷载方式。方法中的节点调整对结构力学性能的改善贡献较多。对节点调整前后结构的稳定性进行验算，结果表明调整后结构不仅可提高结构刚度，且可提高极限承载力和改善初始节点偏差对结构的影响。虽然以应变能作为目标函数，但可同时改善多项力学性能指标：结构刚度，结构极限承载力，结构力学性能的稳定性等，这些力学性能在演化过程中具有同时改善的趋势。文中方法用Fortran语言编程实现，用ANSYS有限元软件考察了方法所得结构的一些力学性能。本文还获得了一套杆系结构形态创构程序。
[Abstract]:The structure form creation structure is one of the emerging research directions in the intersection of architecture and structure, which is from the structural analysis to seek a variety of "Good" The theoretical method of building shape has deep meaning for the further development of architecture and structural design. The structure type of the rod system is numerous, which is widely used in practical engineering, and the research on the shape-building method of the rod system structure has higher application value and contributes to the diversification of the form of the building. Based on the theory of structural optimization, this paper takes into consideration the constraint condition of building space and maximizes the structural rigidity as the design goal, and puts forward the method of constructing the rod system structure with the shape, topology and section. In the method, the generality of the program is taken into account so that the method can be used for the morphogenesis of various rod system structures. This paper mainly carries out the following aspects: 1. The nodal modulation of the structure of the rod system is established. Based on the relation of strain energy and nodal coordinate, the expression of strain energy sensitivity of node is derived, and it is taken into account. The constrained conditions are restricted, and the mobility strain energy of constrained nodes is obtained. In this paper, the characteristic of the sensitivity of the node moving strain energy is analyzed in detail, and the rod system structure with maximum structural rigidity is proposed according to the sensitivity of strain energy to the coordinate of the node. In order to improve the efficiency of evolution, the method for correcting the direction of movement of the node is further studied, and the method for constructing the shape of the rod system structure is further studied. An improvement was made. It was found that in the convergence stage, the node movement sensitivity tends to be zero, and the structure of this phase has no effect on the initial defect. a sensitive feature. A rod-tied knot with topology and shape is proposed. In order to evaluate the contribution of each unit to the resistance load in the whole structure, the structure topological form-forming method defines the sensitivity of the cell increase/ decrease strain energy and uses it as a measure By means of the characteristic of increasing the sensitivity of the unit to increase or decrease the strain energy sensitivity, the strategy of cell increase and decrease is studied, and the node adjustment is combined, and a balance is put forward. The invention realizes the topology change of the structure by directly eliminating the low-efficiency unit and increasing the unit in the vicinity of the high-efficiency unit, The initial structure of the method is simple, in that method, the cross-section optimization is also introduce in the method, so that the method can balance the shape, The method is widely used and can be used in plane and space. The shape of the structure of all kinds of rod systems is invasive. 3. In the form of the rod structure, In the construction method, the constraints of building space are taken into account to enhance the practicability of the method, and B-spline curve (curved surface) is adopted to express the space constraint conditions proposed by the building. the reaction is given during the derivation of the strain energy sensitivity, furthermore, the influence of the initial structure on the final structure is also utilized, because the initial structure is the starting point of the structural evolution, the basic possible space is also provided for the generation of the new rod, It plays an important role in the realization of the restriction condition of the building space. It also enhances the practicability of the method by processing the space constraint conditions in different applications. At the same time, it also enriches the content of structural form-building method. 4. The application of the method in plane and spatial structure in order to explore the applicability of the method, the structure in the plane and spatial structure, The tree-shaped structure, bridge type structure and so on have been calculated Example application practice. Example shows the applicability and practicability of the method. For different bearing conditions, different initial structural conditions, different conditions, In this paper, the structural changes and mechanical properties of the structures in the evolution process were investigated. This paper sums up the influence of the creation strategy on the structural changes and the characteristics of the method. The graceful arc shape, which is beneficial to the realization of aesthetic intention in architectural modeling. At the same time, the resulting structure form The Concept of Mechanical Mechanics can be a Structural Mechanics Education and Structural Design Reference is given. 5. The mechanical properties of the structure obtained by the method are studied and summarized. From the change of the mechanical quantity of a large number of examples, it can be seen that both the topology and the shape of the rod are considered. The structural shape-building method can make the structure provide rigidity to the structure. In the direction of high bending moment, the final structure will take axial force as the main axis. The node adjustment in the method contributes more to the structural mechanics performance. The stability of the structure before and after the adjustment of the node is checked, and the result shows that the post-adjustment structure can be improved not only The structural stiffness can improve the ultimate bearing capacity and improve the effect of the initial node deviation on the structure. Although the strain energy can be used as the objective function, several mechanical performance indexes can be improved at the same time: structural rigidity, structural limit bearing capacity, structural mechanics, The stability of properties, etc., these mechanical properties have a tendency to improve at the same time during the process of evolution. Programming realization, using ANSYS finite element software to study
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU32

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