桁架结构再利用设计研究

Research on reuse design of truss structure

结构构件在其使用年限内的再利用可以有效减少新材料的采购,降低多余材料浪费,且其能耗较低,对环境影响较小。从此角度出发,提出一种结构优化技术重新设计桁架结构,使其能最大限度地利用已有库存结构构件。但从回收构件的库存中设计结构与传统的结构设计规范并不相同,故进一步提出了采用迭代方法从杆单元出发设计桁架系统的离散结构优化公式。具体方法为:首先进行库存分配和拓扑优化;随后进行几何优化,使系统几何与所分配的单元长度匹配。同时结合两个实际案例开展研究:1)简单布局的悬臂结构,用来解释设计方法的细节;2)复杂布局的火车站屋顶结构,由已拆卸的输电塔中可再利用的构件组成。最后对两个案例中结构进行结构生命周期评估,得出的结果表明,采用本文方法获得的再利用结构尽管有更大的质量和更低的材料利用率,但其可以极大限度减少资源的浪费,且对环境造成的不良影响更小。

The reuse of structural components in their service life can effectively reduce the procurement of new materials, reduce the waste of redundant materials, and its energy consumption is low, with little impact on the environment. From this point of view, a structural optimization technology to redesign the truss structure was proposed to maximize the use of the existing inventory of structural components. However, the design of the structure from the inventory of recycled components was not the same as that according to the traditional structural design code, so the discrete structural optimization formula of truss system design was proposed from the pole element design method. The specific methods are as follows: firstly, the inventory allocation and topology optimization were carried out;secondly, the geometry optimization was carried out to make the system geometry best match the element length allocated. And two practical cases were studied: the cantilever structure with simple layout was used to explain the details of the design method;the other was the roof structure of the railway station with complex layout, which was composed of reusable components in the transmission tower. At last, the structural life cycle assessment of two cases was carried out, and the results show that although the reuse structure obtained by this method has greater quality and lower material utilization, it can greatly reduce the waste of resources, and has less adverse impact on the environment.