基于三点转动约束单杆稳定理论的扣件式钢管满堂支撑架承载力研究

摘要

Using non-linear finite element models with different geometric parameters of the semi-rigid characteristics of the couplers, the critical loads and failure modes of many fastener steel tube full hall formwork supports with and without bridging were evaluated. Thirteen full hall formwork supports were tested to failure in order to examine the stability behavior and failure modes. The FEM results were well consistent with those of the test. On the basis of finite element analysis and experimental study, simplified models and corresponding formulas were established for the full hall formwork support under uniform load through choosing buckling modes so that the wavelength was two times the lift height. These models and formulas were verified by the experimental and analytical results and turned out to be accurate enough for predicting the strength.%在对直角扣件转动刚度试验研究的基础上，考虑直角扣件的半刚性性质，对大量不同搭设参数下的满堂支撑架进行考虑初始缺陷的非线性有限元分析，得到无、有剪刀撑设置的满堂支撑架的理论承载力及失稳模态。通过13个满堂支撑架的原型试验，对其实际受力性能进行研究。有限元结果与试验结果吻合较好，证明了有限元模型建逻的正确性。在有限元分析及试验研究的基础上，基于设置剪刀撑后发生失稳时波长为两倍步距的极限状态，提出计算满堂支撑架承载力的简化计算模型，此种模型考虑了直角扣件半刚性性质及水平杆对立杆稳定性的影响，更加符合实际。