Study On Plastic Bearing Capacity Of Large Span Portal Frame Oblique Beam

In recent years,the rapid development of economic construction has brought about the rapid development of China's construction industry.Light steel structure industry optimization is particularly evident.The portal frame steel structure is a very important structural system in the light steel structure.It has many advantages compared to other structures,such as light weight,quick manufacture,installation,short construction period,the flexible architectural style,suitable for large space design,good energy-saving effect,higher price advantage and so on.The span of portal frame is expanding.For the span of more than the "portal frame light steel structure of the technical regulations," the provisions of the rigid frame of the largest span of 36 m portal frame design related information is still lacking.Therefore,the research on the large span portal frame has an important influence on the development of the steel structure design in China.Through the collection of a large number of portal frame of the relevant information and literature,to further study the development of portal frame,performance characteristics and the development prospects of portal frame.A large number of materials related to plasticity theory and plastic design are collected.The characteristics,application conditions and research status of plasticity theory are analyzed.Through the simulation analysis using PKPM-STS software,research on bearing capacity of plastic span in practical engineering for 120 m continuous large span portal frame beam.The main contents of the research include:(1)According to the flexural bending stress analysis process,"code for design of steel structure"(GB50017-2003)and the "code for design of steel structure"(GB50017-201X)and other manuscript plastic theory related information,Comparative analysis of elastic-plastic theory and plastic theory.(2)For the large span gantry span engineering 120 m rigid frame beam,using STS in PKPM software,the elastic-plastic simulation and plastic simulation of different sections are compared.(3)Under the same conditions,compared with the same cross section beam elastic-plastic and plastic ultimate bearing capacity,stress ratio,shear stress ratio and stress ratio overall stability.(4)Under the same conditions,comparison of different section beam plastic limit bearing capacity,strength stress ratio,shear stress ratio and stress ratio overall stability.(5)Comparison on steel quantity of the continuous large span portal frame beam with different section steel.The span of large span portal frame 120 m beam were compared with plastic and plastic simulation,analyze the economic,practical and development space of this kind of structure.