双肢冷弯C型钢蒙古包刚架稳定性试验

Stability Test on Double-Limb Cold-Formed C-Shaped Steel Yurt Rigid Frames

基于草原地区冷弯型钢蒙古包研究的基础,以其一榀平面刚架为研究对象。对5榀刚架进行稳定性试验及有限元模拟研究,分析其破坏模态、承载力、柱顶侧移、屈服机制等,探究斜梁坡度及高跨比对刚架稳定性的影响。结果表明:刚架破坏主要是以梁上、下端C型钢局部屈曲导致整体平面内失稳;增大斜梁坡度和减小高跨比均能提高刚架承载力,提高刚架整体稳定性;刚架柱顶侧移随着斜梁坡度增加而增大,高跨比对柱顶侧移影响较小;刚架斜梁坡度和高跨比的增大均会使刚架柱顶部屈曲破坏提前,改变刚架整体破坏模态;设计时应综合考虑斜梁坡度对柱顶侧移和承载力的影响,合理增加刚架柱刚度,可防止柱顶侧移过大导致刚架失稳。最后采用有限元与试验进行对比并相互验证,为此类结构深入研究提供参考。

Based on the study of cold-formed steel yurts in grassland areas,a one-bay planar rigid frame was used as the research object.Stability tests and finite element simulations were carried out on a 5-bay rigid frame to analyze its damage modalities,bearing capacity,column top lateral displacement and yielding mechanism,etc.,and to investigate the effects of inclined beam slope and depth-span ratio on the stability of the rigid frame.The results showed that the damage of rigid frame was mainly caused by the local buckling of C-beam at the top and bottom of the beam,which led to the overall in-plane instability;increasing the slope of inclined beam and decreasing the depthspan ratio could advance the bearing capacity and the overall stability of rigid frame;the lateral shift of the top of rigid frame column increased with the raise of slope of slanted beam,but the depth-span ratio had less effect on the lateral shift of the top of column;the increase of slope of inclined beam and depth-span ratio would advance the buckling damage of the top of rigid frame column and change the overall damage modality of rigid frame;the design should consider the influence of slope of inclined beam on column top lateral shift and bearing capacity,and increase the rigidity of rigid hing column reasonably to prevent the column top lateral shift from causing the instability of rigid frame;comparison and cross-validation between finite elements and tests were used to provide a reference for further research into such structures.