Research On The Fire-Resistant Performance Of Double C Type Cold-Formed Thin-walled Steel Composite Wall System

In our country,the rural houses are generally built in the way of self construction,without normal design and construction,the quality is difficult to guarantee,which leads to the phenomenon of serious damage or collapse of rural houses in many domestic earthquakes.The development of prefabricated buildings is a measure to solve the problem of rural housing.The double-C cold-formed thin-walled steel composite wallboard construction system adopts double-C cold-formed thin-walled steel and light thermal insulation material composite wallboard,which is produced once in the factory and installed with fire-proof panel on site.This kind of housing system has the advantages of good heat preservation performance,convenient installation,superior stress performance and low cost,which is very suitable for the majority of rural residential buildings.At present,no one has studied the fire resistance performance of the double-C cold-formed thin-walled steel composite wall panel system,and there is no formula for determining the thickness of the fire-proof panel in the code for fire protection design of building steel structures(GB51249-2017)in China.In this paper,the fire-resistant performance of the doubleC cold-formed thin-walled steel composite wallboard system is studied(1)according to the standard temperature rise curve of indoor fire and the related theory of heat transfer,through the ANSYS thermal analysis module,the finite element model of the temperature field analysis of the wallboard system is established,the changes of the temperature field of the wallboard system at different times are analyzed,the distribution rules of the temperature field of the wallboard system and the factors affecting the temperature field of the wallboard system are obtained,and the temperature of the wallboard system is verified by the test data The analysis results of degree field.(2)according to the different fire panel thickness,different fire panel materials,different wall thickness,different wall fillers,different light steel joist spacing and different light steel joist thickness,the paper analyzes the heating law of light steel joist under fire.The results show that the thickness,type and wall fillers of the fire panel have a great influence on the temperature field of the light steel joist section on the fire side,while the Other factors have little influence.(3)according to the comparison of different specifications,the fire endurance requirements of the double C cold-formed thin-walled steel composite wall panel system are determined.The finite element model of the wall system under 81 indoor standard temperature rise curves is established by ANSYS,and the temperature values of the cold-formed thin-walled steel in different time under different fire protection conditions are obtained.The data obtained by the 1stopt method and the general global method are used The optimization algorithm of the optimization method is fitted and regressed,and the calculation formula of the temperature rise of the cold-formed thin-walled steel column and the calculation formula of the thickness of the fire-proof panel of the wall panel system are obtained.Through a calculation example,the calculation process of the thickness of the fire-proof panel of the wall panel system meeting the fire resistance limit is introduced.