风雪荷载下轻钢门式刚架极限承载力分析

以我国沿海一既有门式刚架轻钢厂房为例,按现行规范取用风荷载组合和雪荷载组合,采用精细有限元方法对厂房中的典型刚架进行了非线性的极限承载力分析,获得了刚架抗风与抗雪的承载力冗余系数以及达到极限状态时的破坏模式。结果表明,刚架在不同荷载组合下的承载力虽能满足规范要求,但当考虑初始缺陷时,其承载力冗余系数偏低,且失效模式由无缺陷时的材料屈服模式转变为局部屈曲模式。

ULTIMATE LOAD-CAPACITY ANALYSIS OF LIGHT-WEIGHT STEEL PORTAL FRAMES UNDER WIND AND SNOW LOADING

Nonlinear ultimate limit state analysis was performed to a typical frame of an existing light-weight steel portal frame industrial building located at the coastal region of China using the refined finite element method.The wind and snow load combinations were determined from the current load code of China,and the corresponding wind-resistant and snow-resistant load-capacity redundant factors of the frame were then found through the analysis.The obtained results indicate that although the load-capacities of the frame under the two load combinations meet the current code requirement,the load-capacity redundant factors are relatively low if initial imperfections of the frame are considered.Furthermore the failure mode of the frame would change from a material yielding format to a local buckling format under consideration of initial imperfections.