端部加强型双重钢管屈曲约束支撑影响因素研究

Influencing Factors on End-enhanced Double-steel Tube Buckling Restrained Braces

利用ANSYS软件对端部加强型双重钢管屈曲约束支撑进行单调加载,研究约束比、间厚比和径厚比等构造参数对支撑极限承载力的影响;通过APDL语言二次开发,分析临界约束比、临界间厚比和临界径厚比的取值范围。研究表明:约束比是影响屈曲约束支撑性能稳定发挥的重要因素,在不考虑初始缺陷情况下约束比不应小于1.5;当约束比满足要求时,随着内核钢管径厚比的增大,其临界间厚比上限值呈降低趋势,变化趋势接近于直线,临界间厚比应不大于0.18;约束比满足要求时,随着间厚比的增大,其临界径厚比上限值呈降低趋势,临界径厚比应不大于29。

The influence of factors such as constraint ratio,gap-thickness ratio,and diameterthickness ratio on the ultimate bearing capacity of end-enhanced double-steel tube buckling restrained brace(BRB)is studied using ANSYS software to simulate monotonic loading.Through the secondary development of APDL,the critical constraint ratio value range,critical gap-thickness ratio,and critical diameter-thickness ratio are analyzed.The results show that the constraint ratio is an important factor affecting the stability of BRBs and should not be less than 1.5 without considering initial imperfections.When the constraint ratio meets this requirement,the upper limit of the critical gap-thickness ratio decreases with an increase in the diameter-thickness ratio of the core tube,and the change trend is close to a straight line.The critical gap-thickness ratio should not be more than 0.18.When the constraint ratio meets this requirement,the critical diameter-thickness ratio decreases with an increase in the gap-thickness ratio,and the critical diameter-thickness ratio should not be more than 29.When the diameter-thickness ratio is too large(more than 29),it is prone to high order buckling and failure,resulting in full-section yielding.