Analysis Of Frame Structure Temperature Effect And Suggestion On Expansion Joint Space

At present,there are several problems in the setting of expansion joints in the structural design process at home and abroad:（1）"Specifications for Design of Concrete Structures"GB 50010-2010 gives the maximum spacing of expansion joints for structures such as shelving,frames,shear wall structures,retaining walls,basement walls and other structures.GB50017-2017only gives the length limit of the temperature section of single-storey houses and open-air structures,and does not give the value of the temperature expansion joint spacing of multi-layer or high-rise frames and structures that take thermal insulation measures;（2）Regarding the value of the expansion joint spacing given in the"Specifications for the Design of Concrete Structures"GB50010-2010,the specific setting basis cannot be verified.Most of them are the results of experience and statistics.The research on the factors affecting the expansion joint spacing has no quantitative information;（3）There are no clear and unified provisions on the setting of expansion joints in multi-story steel frame structures in China’s current codes.Designers can only analyze each project individually according to the specific situation.The process is tedious,time-consuming and labor-intensive.The research materials are still lacking and need to be expanded and improved;（4）With the improvement of China’s overall national strength,in response to the government’s call,actively promote supply-side structural reforms and new urbanization development.Buildings made of steel are used in large-span spatial structures,light-portal structures,multi-storey and small high-rise residences.The field has been promoted and applied in many ways.Steel structures play unique advantages in terms of"high","large",and"light",but steel structures are highly sensitive to temperature.The temperature internal forces generated in the structure caused by extreme environmental temperature changes can cause building structures Negative Effects.Temperature stress is a factor that designers cannot ignore in structural design.Temperature expansion joints are a structural measure proposed to reduce temperature stresses.For structural designers,explore the impact of temperature changes on building structures and expand and contract The reasonable value of the joint gap has certain practical significance,and based on the high-speed and diversified development of the construction industry in China,the value of the joint gap of steel frame structures is an urgent problem.Based on the above problems,this article has done the following research work:（1）This article consults a large amount of data on temperature and climate,understands the classification and characteristics of temperature loads,and combines the characteristics of climatic temperature in various regions of the country to discuss the temperature load conditions that the building structure may encounter from construction to normal use.The analysis of the working conditions and working conditions that are relatively long and the most consistent with the actual situation,from the aspects of temperature characteristics of building materials,building insulation measures,specifications,conventional values of actual engineering,etc.Calculate the value of temperature difference applicable to most areas in China;（2）Based on collecting and consulting a large amount of relevant information,this paper sorts out and understands the literature on the temperature effect of buildings,selects the appropriate finite element analysis software Midas/Gen as a tool,and uses this software for different temperature load conditions and different The analysis of a single member under constraint conditions,the internal force and deformation of the member under different working conditions and constraints are obtained,and the feasibility of the software is verified by comparing with the theoretical calculation results;（3）The finite element software model is used to analyze the temperature internal force distribution of the concrete frame structure and the steel frame structure under two temperature load conditions,the temperature internal force of each component（beam,slab,column）,and the deformation characteristics of the overall structure;（4）Through the establishment of a large number of models,the structure length,frame column cross-section size,bottom column height,floor height,floor thickness and other factors were calculated and analyzed to obtain the degree of influence of various factors on the temperature effect of the structure under two loading conditions;（5）From the two temperature load conditions,choose the long-term,closest working condition of the building as the background to discuss the gap between expansion joints,and find out the unfavorable members in the concrete frame structure and steel frame structure under this load condition.,Choose the control member among the components that are not subjected to the force,and use the internal force of the control member as the basis for the expansion joint;（6）Through a large number of model calculations,give different factors（length of the structure,the underlying high columns,column cross-sectional dimension,the height,slab thickness）at varying,55m concrete frame structure to control the temperature of the internal force member delta Capacity ratio accounted M_T（y）/M_u,Proportion of temperature internal force increment of control members of steel frame structure under different influence factors(M_T（x）（10）M_T（y）)/M_u,reduced to stress ratio iss_T/f_y;（7）Conditions for controlling the temperature section length of steel frames:As the temperature section length increases,the temperature internal force ratio of steel members also increases.The temperature internal force ratio of steel members is(M_T（x）（10）M_T（y）)/M_u.When the temperature internal force ratio of the steel structure is consistent with the temperature internal force ratio of the concrete frame structure in the maximum temperature section,the space between the expansion joints of the steel frame is obtained.