轻钢厂房屋面钢檩条加固方法和承载力试验研究

EXPERIMENTAL RESEARCH ON REINFORCEMENT METHOD AND BEARING CAPACITY OF STEEL PURLINS ON ROOFS OF LIGHT-GAUGE STEEL PLANTS

随着光伏发电项目的不断增多,越来越多工业厂房屋面上需增设光伏发电板。屋面使用荷载的增加,导致檩条不能满足承载力要求,需对檩条进行加固设计。结合5 MW自发自用分布式光伏发电项目背景,基于增大截面加固法,提出一种适用于钢檩条加固的新方法,即在原C形截面檩条下翼缘处增设L形角钢构件来进行加固,两者之间通过抽芯铆钉连接。在此基础之上,对3根加固后钢檩条试件开展承载力试验,考察檩条的破坏模式与受力性能,获取了各试件的荷载-位移曲线、荷载-应变曲线、承载力与刚度等。通过有限元软件ABAQUS,对各试验试件建立了准确的有限元模型,并开展数值模拟分析,对比分析了有限元结果与试验结果,验证所提出的加固方法的有效性。研究结果表明:所提出的钢檩条加固方法是切实可行的,加固后钢檩条的承载力和刚度均满足相关技术标准的要求,且极限承载力约为原檩条承载力设计值的1.49倍。

With the increase of photovoltaic power generation projects, more and more industrial plants have been equipped with photovoltaic panels on the roofs. With the increase of service loads on roof, purlins can not meet the requirements of bearing capacity, so it is often necessary to be reinforced. Combined with the background of a 5 MW self-consumption distributed photovoltaic power generation project, a new method for purlin reinforcement was proposed based on the reinforcement method of enlargement sections, that was, L-shaped angle steel was added at the lower flange of the original C-section purlins for reinforcement, and the two were connected by core-pulling rivets. On that basis, the bearing capacity tests of three reinforced steel purlin specimens were conducted to study the mechanical properties and failure modes of purlins, and the load-displacement curve, load-strain curve, bearing capacity, and stiffness of specimens were obtained. Through the finite element software ABAQUS, the accurate finite element models of specimens were constructed, and the numerical simulation analysis was conducted. The finite element results and test results were compared and analyzed to verify the accuracy of test results and the effectiveness of the new reinforcement method. The results showed that: the new reinforcement method of C-section steel purlins proposed in the paper was feasible. The bearing capacity and stiffness of the reinforced steel purlins could satisfy the requirements of relevant specifications, and the ultimate bearing capacity was about 1.49 times of the design value of bearing capacity of original purlins.