Research Of Tensioned Cable-membrane Greenhouse Structure Analysis And Design

With the development of the agriculture facilities, all types of greenhouse in China's agriculture facilities has been widely applied, and has developed rapidly since Twenty-first eighties. From the "Ninth Five-Year Plan", the state started the implementation of "factory high-efficiency agriculture demonstration project",it promoted the development of China's greenhouse a new stage, took Beijing, Shanghai, Tianjin, Shenyang, Hangzhou, Guangzhou and other regions as a leader in science and technology demonstration bases. Greenhouses (including plastic greenhouses) production area expanded rapidly, from less than 20,000 hm2 in early 50's to today's approximately 900,000 hm2, accounting for more than 50% of the total area of global greenhouses. so our country becomed the world's largest vegetable production areas (Bao-Ming Lee,2003). In recent years, the overall level of infrastructure projects have improved markedly. Facility types plastic greenhouses and solar greenhouses-based, step by step to the large-scale, diversified development.It should be noted that the widely used greenhouse currently is structurely simple and narrow. it is difficult to conduct mechanized operations; the capacity of bearing wind, snow, ice and other natural disasters is very poor. once the disaster Encountered it will collapse in lardge scale, It has seriously hindered the development of agriculture facilities. Time before and after the Spring Festival in 2008,the frozen and snow disasters caused serious damage to agriculture in southern China, almost all greenhouses collapsed in affected areas, crops in greenhouses destroyed, it resulted in enormous losses to China's economy.In this paper, the first time, cable-membrane structure system is applied to the area of greenhouse structural design, a new type of greenhouse structure-tensioned cable-membrane greenhouse structure is proposed. steel cables is used as a mainly component in the structure. through the imposition of pre-tension steel cables, it provide the structural the necessary rigidity, the bearing capacity is greatly enhanced than troditional greenhouse structures. Compared with the traditional greenhouses, tensioned cable-membrane greenhouse structure has such advantages as stronger ability to resist natural disasters, larger-span for mechanized operations, needs less materials and lower construction costs.It is more suitable for China's national conditions.In this paper, the theory of tensioned cable-membrane greenhouse structure analysis is systematic studied,and the structure is analized,by 3D3S--a non-linear structural analysis and design software. the laws of parameters affecting the mechanical properties of tensioned cable-membrane greenhouse structure is obtained, the basis and method to determine the structural parameters is summed up; in this article,I also designed sevral dedicated node for this special structure; at the end of the paper,I designed four structure of different span. Comparison with the traditional greenhouse structure, it provide further evidence of the advantages of the new type greenhouse structure.