Research On Lateral Resistance Performance And Modularization Of Plug-in Temporary Structure

Temporary structure refers to a new type of energy-saving and sustainable structure which can be quickly assembled and reused according to customized requirements.Facilities and platforms based on temporary structure technology h ave become an important device for human development and a strategic reserve for the country to deal with the uncertain future.The new design challenges are improved as the special performance of temporary structures.The challenges contain not only the different constraints for the spatial system,but also the joint assembly and disassembly efficiency,manufacturing error allocation,installation precision debugging,damage rate control,intelligent installation and control,joint rigidity parameters,loads and fields evaluation,which are all the key problems to be solved urgently.Early research on temporary structures mainly focused on scaffolding and formwork support and similar structures in the field of engineering.With the explosive growth of the application of temporary structures,loads,deformation mode and restraint conditions of traditional temporary structures have changed fundamentally.Due to the requirement of rapid assembly and disassembly,great difficulties on the design of temporary structures occur,resulting in the single form of temporary structures.Developing new temporary structures,especially exploring new joint structures,to meet and highlight their key qualities,is the core scientific problem to be solved urgently in the research of temporary structures.This thesis,supported by National Technology Supported Plan with the grant number of 2014BAK14B05,presents a comprehensive research on the lateral resistance performance of the plug-in structure and the joint construction.The new mechanical performance of the plug-in structure is discovered and the new joint connections are explored.Based on the theoretical research and engineering practice,the research contents and results are as follows:(1)The multi-group joint tests were carried out with the plug-in temporary structure as the research object,and the polyline models of the joint were obtained.A new binocular stereo vision measurement system is designed according to the characteristics of deformation and load effect of temporary structure.The improved matching algorithm for non-contact measurement of temporary structure is proposed,and three-dimensional measurement method for multi-point displacement of temporary structure is obtained.The numerical model of the joint of temporary structure is established,and the stress distribution of the joint under loads with different direction is found.(2)The initial geometric imperfections of the multi-group plug-in temporary structures are measured and statistically analyzed.The probability distribution models of the member out-of-straightness and story out-of-plumb are obtained.A series of bidirectional loading tests for the temporary structures unit are conducted.The ultimate lateral bearing capacity,failure mode and stress distribution of the member were obtained when both vertical load and horizontal load acted on the plug-in temporary structure.The nonlinear stochastic numerical models of the plug-in temporary structure with consideration of joint stiffness and initia l geometric imperfections are established,which can predict the quantitative results of internal forces and structural effects of temporary structures under vertical and horizontal loads.(3)The influences of the semi-rigid of the horizontal bar and the eccentricity of bracing joint on the lateral capacity of the structure are further analyzed.The comprehensive influences and quantitative evaluation method of span,layer and vertical load on the lateral capacity of the structure are put forward.Through the calculation of more than 40,000 random models,the theoretical calculation method of the lateral bearing capacity of the structure is obtained.The simplified design of temporary platform structure,temporary stand and temporary ski run based on ABAQUS matrix calculation is realized by Python programming.(4)Based on the study of plug-in temporary structure,a modular foldable and reusable assembly temporary structure is proposed.This support system can be used in temporary stands,temporary stages,temporary ski slopes and their subsidiary structures.Field tests show that this technique can significantly improve the customizability and controllable observability of the temporary structure.The stability of the aluminum alloy assembly column,as the core component,was studied.The failure modes and ultimate load-bearing capacity of the component are obtained by means of multi-group component tests and numerical modeling.The influence of the position of the variable rigidity control connection ring an d the pipe spacing on the axial bearing capacity of the temporary structure is further analyzed.The practical formula for the axial stability of the assembly column was given.Based on the above research,this assembly column has been successfully applied to the temporary stand for the 2017～2018 China Skateboard Club League,and has achieved good application results.