冷弯薄壁型钢C形梁受剪性能分析

Shear Behavior Analysis of Cold-formed Thin-walled Steel C-shape Beam

为研究冷弯薄壁型钢C形梁的受剪性能,在已有试验基础上,采用ABAQUS有限元分析软件建立非线性数值模型,对比试验与有限元结果的受剪承载力、试件破坏特征、荷载-跨中挠度曲线等;进而探讨了C形梁剪跨比、腹板高厚比、腹板厚度以及钢材强度等因素对冷弯薄壁型钢C形梁受剪性能的影响。结果表明:剪跨比是影响冷弯薄壁型钢C形梁破坏特征的主要因素,当剪跨比在0.5~1.1之间时,C形梁处于纯剪切受力状态,此时破坏模式为剪切屈服;当剪跨比在1.1~2之间时,C形梁处于弯剪受力状态,此时破坏模式为弯剪破坏;随剪跨比的增加,冷弯薄壁型钢C形梁的受剪承载力及刚度均减小;当腹板高厚比在50~150之间时,冷弯薄壁型钢C形梁的受剪承载力及刚度随腹板高厚比增加而增大,跨中挠度减小;随着腹板厚度的增加,冷弯薄壁型钢C形梁受剪承载力及刚度明显提高;增加钢材强度可显著提高冷弯薄壁型钢C形梁受剪承载力,但对冷弯薄壁型钢C形梁的刚度影响较小。

In order to investigate the shear behavior of cold-formed thin-walled steel C-shape beam,a nonlinear numerical model was built up through the finite element analysis software ABAQUS based on previous experimental study.The correctness of the modeling method was verified by comparing the results of finite element model and that of experiment.The compared results included the shear bearing capacity,specimen failure characteristics and load-mid span deflection curves.Then the effects of shear span ratio,web height to depth ratio,web depth and steel strength on the shear behavior of cold-formed thin-walled steel C-shape beam were investigated.The results show that shear span ratio is the main factor determining the failure characteristics of cold-formed thin-walled steel C-shape beam;when the shear span ratio is at 0.5-1.1,the C-shape beam is in pure shear and the corresponding failure mode is yield stress;when the shear span ratio is at 1.1-2,the C-shape beam is subjected to combined action of bending-shear and the corresponding failure mode is bending-shear failure;the shear bearing capacity and the stiffness of C-shape beam decrease with the increase of shear span ratio;when the web height to thickness ratio is at 50-150,the shear bearing capacity and stiffness of the C-shape beam raise with the increase of web height to thickness ratio,and the mid-span deflection decreases;with the increase of web thickness,the shear bearing capacity and stiffness are obviously improved;the steel strength has significant influence on the shear bearing capacity of the beam,but has little effect on the stiffness of it.