Wind Load And Wind-resistant Analysis Of Large-span Light-weight Steel Industrial Building

Light-weight steel portal frame has the advantages of light weight,short construction period,with flexible layout,high economic benefit,is widely used in modern industrial buildings like the workshop.However,due to light weight,small stiffness,low damping characteristics,portal frame light-weight steel structures are prone to damage under strong wind.Especially in our country vulnerable to typhoon disaster in southeast coastal areas,the main wind-induced damage occurred more frequently.In order to study the wind resistance capacity and the failure mode,a portal frame structure factory in the southeast coastal area of China has been carried on the analysis of wind tunnel test and finite element as an example.Firstly,taking the existing light-weight steel portal frame factory as an example,the rigid model wind tunnel pressure test was carried out to measure the surface wind pressure distribution.According to the different area division method,the partition wind load shape coefficient was calculated and analyzed.The results were also compared with the current load criterion and the Chinese technical specification for light-weight steel buildings.At the same time,the measured wind load shape coefficient was also been used in the finite element analysis of subsequent chapters.Secondly,the three-dimensional finite element model of the portal frame structure was established,and the wind loads were calculated by the results of wind tunnel test.The frame deformation and stress change rule along with the wind angle and the causes of the adverse wind direction were discussed.Finally,the nonlinear ultimate limit load-capacity analysis was performed to the whole frame structure using the finite element method.The wind load was determined utilizing the most unfavorable shape coefficient proposed by the American Society of Civil Engineers standard ASCE 7-10,Chinese technical specification for light-weight steel buildings and the results of wind tunnel test.The corresponding wind-resistant capacity and its failure mode of the frame reaching the ultimate limit state were thus found and also compared.The obtained results indicated that that the negative pressure on the roof and leeward region of this type of structure was generally greater than the middle region under oblique winds.The wind-resistant capacity of this kind of structures under oblique wind was lower than those under the normal wind.The main reason for decrement of load capacity under oblique wind is that local buckling develops at multiple areas within the frame and furthermore occurs earlier than that under the normal wind.