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目前,冷弯型钢抗压构件的LRFD抗力系数取值为0.85,该文旨在研究该系数能否增大。数据库中包含675组同中心荷载柱的试验数据,包含平口卷边C截面、平口卷边Z截面、帽形截面和角形截面以及开孔构件。采用美国钢铁协会标准和直接强度法计算每个试样的强度。直接强度法的计算结果更加精确,其在计算部分有效截面柱的强度时尤为精确。采用一阶二次矩法计算的LRFD抗力系数,与美国钢铁协会标准和直接强度法的规定相符。对于柱的两种破坏情况,达到畸变屈曲极限状态而破坏和由于整体失稳或局部-整体失稳相互作用而破坏,前者的计算结果更为精确。单角钢柱的试验强度与计算强度的比值有很大变化,随着整体长细比的增加,计算结果逐渐变得极为保守。
At present, the LRFD resistance coefficient of cold-formed steel compression member is 0.85, this paper aims to study whether the coefficient can be increased. The database contains 675 sets of concentric loaded columns of test data, including C flat crimping, flat crimping Z section, hat section and angular section and the opening member. The strength of each sample was calculated using the American Iron and Steel Institute standards and direct strength method. The result of the direct intensity method is more accurate, which is especially accurate when calculating the strength of some of the effective section columns. The LRFD resistance coefficient calculated by the first order second moment method is consistent with the regulations of the American Iron and Steel Institute standard and direct strength method. For the two kinds of damage of the column, reaching the state of distorted buckling limit and the damage and the failure due to the global instability or the local-global instability interaction, the former results are more accurate. The ratio of experimental strength and calculated strength of single angle column greatly changes. As the overall slenderness ratio increases, the calculation result becomes extremely conservative.