考虑蒙皮效应的轻钢檩条极限承载力分析研究

Stability bearing capacity analysis and experimental study on purlins considered diaphragm effect

压型钢板在其自身平面内具有很大的抗剪能力,其参与结构整体受力,对主体结构有加强作用,提高了结构的空间整体性,此被称为压型钢板的蒙皮效应。为了使应力蒙皮效应在工程中尽快得到应用,对蒙皮支撑C型檩条在竖向荷载作用下的稳定承载力进行了理论分析和试验研究,应用有限元方法分析了有、无蒙皮支撑两种情况下檩条的极限承载力,探讨了蒙皮板对檩条的侧向支撑和扭转约束作用机理。结果表明:檩条在有蒙皮情况下,受力后侧移、扭转角和内部应力均比无蒙皮支撑时减小,稳定承载力提高约20%。

Profiled steel sheet has a large capacity of shear-resistance in its own plane and the sheet overall force on the structure strengthens the performance of structural entirety,which is called stress-skin effect.To apply stress-skin effect to engineering,the author carries out the stability capacity analysis and experimental study of the diaphragm-braced C purlin subjected to the vertical load and discusses the mechanisms of the lateral support and the reverse constraint to the purlins by the skin sheet.Through the finite element method,the author also analyses two situations of the ultimate bearing capacity of the purlins with or without the skin support.Compared with the existing national standards,the results show that,with the skin effect,the lateral displacement,torsion angle and the insert stress are reduced,and the bearing capacity is increased by about 20 percents.