大开口车辐式索承网格结构构建及其受力机制和找形研究

Mechanical behavior and form-finding research on large opening spoke-wheel-type cable supported grid structure

提出了大开口车辐式索承网格结构,其适用于体育场、足球场等大跨空间屋盖结构体系。介绍了该结构的型体构成和基本受力原理,并对结构的受力机制进行探讨。该结构由刚性网格、索杆体系、内环带桁架及内环悬挑网格组成,其中张拉索杆为刚性网格提供竖向支撑,刚性网格起到压环作用,结构在水平面内为一自平衡体系;内环带桁架将径向索承结构联系在一起,增加结构的空间整体性,提高了结构的刚度和承载力;内环悬挑网格增加刚性网格压环宽度,进一步提高了结构的承载力。分析了现有找形方法存在的问题,提出了适用于该结构体系,并可保持撑杆竖直、控制撑杆高度的找形方法,并编制计算程序,通过算例验证了该找形方法的有效性。

A large opening spoke-wheel-type cable supported grid structure is proposed, which is suitable for the roofs of stadiums. The basic configuration and the force transfer mechanism of such structure are described. The structure is composed of a rigid grid, a cable strut system, an inner ring truss and an inner cantilever grid. The cable strut system provides vertical support, and the rigid grid acts as a compressive ring. These make the structure a self-balancing system in the horizontal plane. The inner ring truss links to a series of radial cable-supporting stuctures, increasing the spatial integrity and greatly enhancing the stiffness and bearing capacity of the structure. The cantilever inner grid increases the width of the rigid grid and therefore to further increase the bearing capacity of the structure. Based on the basic load carrying mechanics, some problems in terms of form-finding methods are pointed out. An appropriate form-finding approach which is applicable to large opening spoke-wheel-type cable supported grid structures and concurrently ensures vertical rods with required length is proposed and programmed. The improved methods are proved to be effective by providing an illustrative example.