Design On Point Loading Test Rig Of Large Space Structures

With the mushrooming of many exhibition centers, stadiums and airports nationwide, there is a increasing in social demand and engineering application of wide-span space structure. However, most of the nodal points loading test devices that are currently working belong to plane loading type, having poor versatility, unable to meet the loading requirement of large nodal points of the spatial structures. This article design an omni-bearing loading system for test of nodal points of the spatial structures. Its advantages are big loading capacity, high automaticity and synchronous loading of multiple nodal points. It applies to the extension and compression test of most nodal points in engineering practices.The first chapter presents a general view of spatial structure development, classification of structure test and methods of loading. It explains the design requirements and realizable functions of an omni-bearing loading system for test of nodal points of the spatial structures.The second chapter proposes a double guide rail loading design which provides 9 nodal points. The design includes schematic design of guide rail, design of carriage oil cylinder, connections, sample conveyance devices and automatic on-off devices of goal. The dead zones exist in loading system and corresponding measures for reduction are analyzed.The third chapter introduces the embedded guide rail loading design, an improvement made on the basis of double guide rail loading proposal. A different guide rail is adopted to reduce loading dead zone to almost zero in an attempt to satisfy the loading requirement of commonly used nodal points in engineering projects. A detailed introduction is made to the function of upper and lower positioning carriage of loading system, structure design and calculation and verifications according to actual components.The forth chapter is a FEM analysis of key part of the embedded guide rail loading system. It analyzes the stress in the radial guide rail and the front supportingof carriage and their deformation.The fifth chapter is a conclusion of the article, and an outlook is included.