| The standing seam aluminum-magnesium-manganese alloy roofing system is widely used due to its excellent waterproof performance and good resistance to temperature stress.However,the characteristics of light weight and weak connection lead to a large number of wind-exposure accidents under the design wind speed.This paper focuses on the standing seam metal roof system formed only by the mechanical locking of aluminum-magnesium-manganese alloy roof panels and fixed supports,establishes a refined finite element model,and investigates the simplified model and the classification method of wind resistance performance level in the performance-based design method.The main contents are as follows:(1)In view of the oversimplification and incomplete size of the previous finite element simulation of the node connection,a refined finite element model is established:using ABAQUS software,introduce contact pairs to reproduce the actual connections of the roof system,and solve the nonlinear problem of the T-shaped bearing in the roof system at the connection with the rib;restore the extended edge of the rib of the roof panel,simulate the interaction between the rib and the vertical edge of the adjacent plate at the actual connection,and reduce the simulation error;carry out the wind resistance test on the simulated size to restore the size 1:1 to eliminate the influence of boundary conditions.Compared with the wind resistance test results under the same conditions,the effectiveness of the simulation method is verified.(2)Through the simulation of 15 sets of commonly used plate type,the data of finite element simulation results confirm the limitations of existing specification calculation model and improvement: width calculation section of having support constraint,and the special connection results in uneven bending section width of contribution,equivalent principle based on elastic limit bearing capacity to modify the original calculation model for plate length direction;Plate relatively wide plate length factors on the ultimate bearing capacity is bigger,the influence of plate width across the small deformation,stiffness in the existing standard calculating methods,supplemented by beam width direction calculation model,with elastic deformation phase displacement as the equivalent principle,using the least squares fitting the equivalent coefficient,the calculated results with the test and simulation comparing the limit state of displacement,proved the reliability of the calculation model.(3)In order to improve the performance of the roof system against strong win at different return periods and realize the performance-based wind resistance design of the roof system,this paper studies the level division of the roof system’s wind resistance performance by analyzing the failure characteristics of the roof system in the whole process of failure:The influences of plate parameters on wind resistance performance under static loading are studied.With the plate width and thickness as the main research parameters,50 working conditions were determined.By analyzing the response results of a large number of samples,the threshold values of two damage indexes of the threestage performance level and corresponding repair methods are defined.In order to eliminate the sensitivity of plate parameters,the damage coefficient β was normalized and fitted according to the rule that the width and thickness of the plate were positively and negatively proportional to the mid-span displacement.The rationality of the index was verified by the results of all samples. |
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