平面墙体树状骨架结构形态创构研究

发布时间：2018-01-11 11:17

本文关键词：平面墙体树状骨架结构形态创构研究　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：墙体树状骨架结构是将树状结构作为墙体的骨架,不仅承受屋面或楼面传递来的荷载以及墙面自重荷载,而且同时装饰墙体达到视觉美观要求的创新结构。墙体作为表皮结构的一种,其形式往往比较单一,树状结构以其形态优美和受力合理的特点已经在建筑主体结构中应用较多,但将其应用到墙体的实例几乎没有,本文是将树状结构应用到墙体以追求力和美完美结合的一种探索,旨在为表皮结构的发展提供一种新的思路。本文主要开展了下列工作:建立了一种平面墙体树状骨架结构形态创构方法。首先根据分形理论的LS生成方法编制程序,实现可以通过改变任意输入参数生成不同的树状分形图;考虑到平面墙体树状骨架结构的杆件之间不可以出现双层交叉的现象,对树状分形图中重合部分和相交线进行适当处理;为了将树状分形图应用于墙体,根据建筑约束条件适当修改其外部形状,完成墙体树状骨架结构的拓扑关系的确定。其次为了在有限元分析的过程中将墙体所承受的荷载传递到墙体树状骨架结构,根据Delaunay三角剖分的Lawson算法编制程序,实现任意平面的三角网格划分;考虑到对墙面进行Delaunay三角剖分时,需要保持墙体树状骨架结构的形态,在程序中加入二维限定条件。再次从结构应变能和刚度的关系出发,将墙体应变能作为目标函数,推导出节点应变能敏感度的计算公式;根据节点应变能敏感度的特性对墙体树状骨架结构的节点进行逐步调整,使其在外形优美的同时受力更加合理,完成墙体树状骨架结构的形状优化。最后基于墙体树状骨架结构形状优化的结果,根据杆件强度、稳定性和长细比的条件对其进行截面优化,实现材料的高效利用。通过具体的算例分析所建立的墙体树状骨架结构形态创构方法的特点和适用性。在形状优化的过程中,随着整个墙体应变能的下降,墙体的位移变小,墙体树状骨架结构的弯矩和剪力也相应减小,但其轴力基本保持不变;墙体树状骨架结构经过形状优化后可以达到以轴力为主的受力状态,说明了通过分形理论确定的树状拓扑关系是合理的;截面优化使墙体骨架结构的应力均匀。通过改变分形文法中的任意参数可以得到不同的树状分形图,将其做适当处理后即可得到初始单层单主干墙体树状骨架结构,再经过复制平移也可得到多主干、单层和多层结构,本文通过多个算例验证了所建立方法的可行性、合理性、高效性、经济性和通用性。最后给出一些应用实例,说明了研究的意义和价值。
[Abstract]:The tree-like skeleton structure of the wall takes the tree structure as the skeleton of the wall, which not only bears the load from the roof or floor, but also the self-weight load of the wall. And at the same time decorative wall to achieve visual aesthetic requirements of the innovative structure. As a skin structure, its form is often relatively simple. The tree structure has been widely used in the main structure of the building because of its beautiful shape and reasonable force, but there are few examples of applying it to the wall. This paper is to apply the tree structure to the wall in order to pursue the perfect combination of force and beauty. In order to provide a new way of thinking for the development of epidermal structure, this paper mainly carried out the following work:. In this paper, a method of creating the shape of the tree-like skeleton structure of the planar wall is established. Firstly, the program is compiled according to the LS generation method of fractal theory. Different tree fractal images can be generated by changing any input parameters. Considering that there is no double layer crossing between the members of the tree skeleton structure of the plane wall, the overlapping part and the intersection line in the tree fractal image are properly treated. In order to apply the tree fractal graph to the wall, the external shape of the wall is modified according to the constraints of the building. The topological relationship of the tree skeleton structure of the wall is determined. Secondly, in order to transfer the load of the wall to the tree skeleton structure of the wall in the process of finite element analysis. According to the Lawson algorithm of Delaunay triangulation, the triangulation of any plane is realized. Considering the Delaunay triangulation of the wall surface, it is necessary to maintain the shape of the tree skeleton structure of the wall, and to add two dimensional conditions in the program. Again, the relationship between the strain energy and the stiffness of the structure is considered. The strain energy of the wall is taken as the objective function and the formula for calculating the sensitivity of the joint strain energy is derived. According to the sensitivity of the joint strain energy, the joint of the wall tree skeleton structure is adjusted step by step to make it more reasonable in the beautiful shape at the same time. Finally, based on the results of the shape optimization of the wall tree skeleton structure, the cross-section is optimized according to the strength, stability and aspect ratio of the members. Through a concrete example to analyze the characteristics and applicability of the shape creation method of the wall tree skeleton structure. In the process of shape optimization, the strain energy of the whole wall decreases. The displacement of the wall becomes smaller, and the bending moment and shear force of the tree frame structure of the wall also decrease correspondingly, but the axial force remains basically unchanged. After shape optimization, the tree skeleton structure of the wall can be subjected to axial force, which shows that the tree topological relationship determined by fractal theory is reasonable. Section optimization makes the stress of the wall skeleton uniform, and different tree fractal images can be obtained by changing any parameters in fractal grammar. After proper treatment, the tree skeleton structure of the initial monolayer single trunk wall can be obtained, and then the multi-trunk, single-layer and multi-layer structures can be obtained after replication and translation. In this paper, the feasibility, rationality, efficiency, economy and versatility of the proposed method are verified by several examples. Finally, some practical examples are given to illustrate the significance and value of the research.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU318

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