G550高强冷弯薄壁Z形钢受弯构件承载力试验与直接强度法研究  

Tests and direct strength method for bearing capacity of G550 high-strength cold-formed thin-walled Z-section steel flexural members

作　　者：赵金友[1] 王钧[1] 王全邦[1] 

机构地区：[1]东北林业大学土木工程学院,黑龙江哈尔滨150040

出　　处：《建筑结构学报》2017年第7期42-50,共9页Journal of Building Structures

基　　金：中央高校基本科研业务费专项项目(2572017CB01);黑龙江省自然科学基金项目(E2015056)

摘　　要：为了研究高强冷弯薄壁型钢构件的受弯性能和完善直接强度法,对卷边形式为斜卷边、直卷边和复杂卷边的12个G550高强冷弯薄壁Z形钢受弯试件进行了静力试验。试验结果表明,卷边形式对试件屈曲模式和受弯承载力有显著影响,试件发生了局部与畸变相关屈曲或畸变屈曲,直卷边试件的承载力高于斜卷边试件的承载力,复杂Ⅱ型卷边试件的承载力高于复杂Ⅰ型卷边试件的承载力。根据试验结果并结合现有国外直接强度法公式,回归出G550高强冷弯薄壁Z形钢受弯构件发生局部与畸变相关屈曲变形时的承载力直接强度法修正公式,当此类构件发生畸变屈曲时,无需再修正现有直接强度法公式。建立有限元模型对试验进行了分析,分析结果与试验结果吻合良好。在此基础上,利用大量有限元分析结果验证了直接强度法修正公式比现有直接强度法公式对此类构件的承载力的预测更为安全可靠。In order to investigate the flexural behavior of high-strength cold-formed thin-walled steel members and develop the direct strength method （DSM）, static tests of twelve G550 high-strength cold-formed thin-walled Z-section steel flexural specimens with inclined, upright and complex edge stiffeners were conducted. It is shown that edge stiffener type has a significant effect on the buckling mode and bending strength of the specimens and the interaction between local and distortional buckling or distortional buckling occurs. The upright edge stiffener specimen exhibits a higher bearing capacity than the inclined one and the complex Ⅱ edge stiffener specimen exhibits a higher bearing capacity than the complex I one. According to the test results and existing abroad DSM formulas, the revised DSM formulas of the bearing capacity of G550 high-strength cold-formed thin-walled Z-section steel flexural members were established when the interaction between local and distortional buckling occurred. It is not necessary to modify the existing DSM formulas when the distortional buckling occurs. The tests were simulated by finite element analysis, and the simulation results agree well with the test results. It is verified that the revised DSM formulas could provide safer and more reliable prediction of bearing capacity of this kind of member than the existing DSM formulas through a large number of finite element analysis results.

关 键 词：高强冷弯薄壁Z形钢 卷边形式 静力试验 受弯承载力 直接强度法 

分 类 号：TU392.1[建筑科学—结构工程] TU317.1