Study Of The Wind-Uplift Resistance Capacity And Wind-Induced Fatigue Damege Of The Self-Trapping Screw-Fastaned Metal Roofing Plate

Compared with the traditional roof, metal roofing has many advantages, sunch as light weight, strong durability, strong appearance adaptability, high economic performance, energy conservation, environmental protection and so on, so its application in variety of large-span space structures becomes more and more common. But this structure is light weight, large flexibility and extremely sensitive to wind load, its main design load is wind load. However in recent years, metal roofing was uncovered, serious leaks and other phenomena due to wind loads occur frequently, these caused serious economic losses and affect people’s life. its wind resistance problems far has not been solved. Therefore, further study on the wind resistance of the metal roofing has important significance.The research object of this article is screw-fastened YX35-125-750 type sheet metal roofing, this paper uses finite element analysis program ANSYS to analyze its wind resistance bearing capacity to keep normal use and wind-induced fatigue properties. The main works of this paper are as follow:(1) First of all, build a reasonable finite element model of the metal roofing. On this basis, establish a failure criterion through a large number of analysis of this type metal roofing. And then, based on this criterion, study four parameters of the roof how to affect its wind resistance bearing capacity of keeping normal use. These four parameters are the diameter of Self-tapping screw head or washer, the thickness of plate,the span of plate and the material yield strength of plate. Finally, based on the analysis of more than 600 groups of different parameters roof plate, fitting a formula which can use to calculate the wind-uplift resistance capacity to keep normal use.of this type metal roofing. This formula can be used to guide the design of this type metal roofing.(2) Studied the fatigue crack initiation life curve the metal roofing under cyclic loading. Combining with the characteristics of damage of roof plate in real and finite element analysis results, chose three fatigue risk points in the finite element model of roof plate to analyze its fatigue life under different constant amplitude cyclic loading, and got the fatigue damage and life of the roof under different cyclic loading. In order to study how different parameters influent the fatigue life of the metal roof, the fatigue life of five different parameters roof plate was analyzed, and then the fatigue life curve of each roof.was fitted.(3) Combined with a specific project, the fatigue damage and life of metal roofing in practical use are carefully analyzed. Base on the wind load distribution and time history on the roof the engineering was got by wind tunnel test. and combined with the fatigue life curve of the roof plate, the fatigue damage of metal roofing in normal and extreme wind was detailed studied, the fatigue risk positions of this project and the fatigue damage of different paraments metal roofing in different use conditions was got.