金属屋面铝板抗风性能数值模拟研究

Numerical Simulation Investigation on Wind-Resistance Performance of the Metal Roof Aluminum Sheet

连续焊接不锈钢金属屋面系统是一种新型金属屋面围护体系,因其易于加工、轻质高强的特点,近年来被广泛应用于体育馆、航站楼、车站等各类大型公共建筑中。连续焊接不锈钢金属屋面系统涉及的问题具有综合性、复杂性,这也导致我国至今还未有金属屋面围护系统的相关施工和管理规范,不利于这类屋面的推广应用。基于上述问题,对连续焊接不锈钢金属屋面系统展开相关研究。首先介绍了金属屋面构造,通过分析连续焊接不锈钢金属屋面系统的构造,总结出其优点:整体性和密封性良好、耐久性优良、维护成本低。基于有限元分析软件MIDAS Fea建立金属屋面铝板数值模拟分析模型,模拟屋面系统在风载作用下的破坏过程,对连续焊接不锈钢金属屋面系统的抗风性能进行研究分析。对金属屋面铝板施加沿z轴正方向的均布荷载8.0 kN/m^2,分析铝板的变形及受力情况。分析结果表明:三角形板的中间位置位移最大,方向主要沿z轴正向;相较于中间位置的板,处在边缘的板由于约束差,位移较大;对于边缘位置板和中间位置板,当荷载达到6.4 kN/m^2时,增加相同的荷载,位移增量变大,即荷载-位移曲线呈非线性增长,铝板产生非线性变形;在8.0 kN/m^2的均布荷载作用下,相邻三角形铝板连接部位的凹槽处应力较大,将率先进入塑性阶段;在三角形铝板中,角点处应力最为集中,故应力增长较快,且应力最大;凹槽处的连接板通过螺栓与下部结构相连,在荷载传递的过程中,屋面三角形板所承受的竖向荷载均通过连接板传给螺栓,由于螺栓连接较弱,容易产生应力集中现象,进而导致结构破坏,必要时应采取相应加强措施。通过对结构的模态分析,得到其前5阶振型和周期。对屋面板进行风压时程分析,得到各测点对应的最大位移、应力响应。在此基础上,结合金属屋面铝板在风吸作用下的破坏模式,提出了提高屋面抗风极限承载力的若干建议。

Continuous welded stainless steel metal roofing system is a new type of metal roofing maintenance system.Because of its easy processing,light weight and high strength,it has been widely used in various large public buildings such as stadiums,terminal buildings,and railway stations in recent years.The problems involved in continuous welding of stainless steel metal roofing systems are comprehensive and complex.This has also led to our country’s lack of relevant construction and management specifications for metal roofing systems,which is not conducive to the promotion and application of this type of roofing.Based on the above problems,this article carried out related research on the continuous welding of stainless steel metal roof system.Firstly,the metal roof structure is introduced.Through the analysis of the structure of the continuous welding stainless steel metal roof system,its advantages are summarized:good integrity and sealing,excellent durability,and low maintenance cost.Based on the finite element analysis software MIDAS Fea,a numerical simulation analysis model of metal roof aluminum panels is established to simulate the failure process of the roof system under wind load,and the wind resistance performance of the continuous welded stainless steel metal roof system is studied and analyzed.A uniform load of 8.0 kN/m^2 along the positive direction of the z-axis is applied to the aluminum plate of the metal roof,and the deformation and force of the aluminum plate are analyzed.The analysis results show that the middle position of the triangular plate has the largest displacement,and the direction is mainly along the positive z-axis;compared with the middle position plate,the edge plate has a larger displacement due to poor restraint;for the edge position plate and the middle position plate,when the load reaches 6.4 kN/m^2,increase the same load,the displacement increment becomes larger,that is,the load-displacement curve shows a nonlinear growth,and the aluminum plate produces nonlinear deformation.Under the uniform load of 8.0 kN/m^2,the stress at the grooves of the adjacent triangular aluminum plates is relatively large,and it will enter the shaping stage first;in the triangular aluminum plates,the stress at the corner points is the most concentrated,so the stress increases faster,and the stress is the largest;the connecting plate at the groove is connected to the substructure by bolts.During the load transfer process,the vertical load on the roof triangular plate is transmitted to the bolts through the connecting plate.Because the bolt connection is weak,stress is likely to occur the phenomenon of concentration,which will lead to structural damage.Corresponding strengthening measures should be taken when necessary.Through the modal analysis of the structure,the first 5 modes and periods are obtained.The wind pressure time history analysis is performed on the roof panel,and the maximum displacement and stress response corresponding to each measuring point are obtained.On this basis,combined with the failure mode of the metal roof aluminum panel under the action of wind suction,several suggestions for improving the roof wind resistance ultimate bearing capacity are put forward.