(兰州理工大学土木工程学院，兰州 730050)
［摘要］对25个结构钢V形缺口板试件进行断裂试验。试验表明：裂纹起始于受三轴强约束的V形缺口厚度心部，随后沿厚度方向扩展，裂纹贯通后迅速沿宽度发展，宏观裂纹大致垂直于载荷方向，单缺口试件断裂延性略高于双缺口试件，薄板断裂延性明显高于厚板。断口呈暗灰色，断口大量韧窝显示出明显的剪切断裂痕迹，断裂类型为正断和剪断混合型断裂，显示了断裂的定性规律。从整体上看，试验数据离散性较小，为研究结构钢断裂机理及抗断理论提供了可靠的试验依据。
［关键词］结构钢；断裂机理；缺口板；初始裂纹
Fracture experiments of structural steel V-shaped notched plates
Wang Wanzhen, Su Renquan, Du Yongfeng, Li Song(School of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050,  China)
Abstract:In order to study rupture mechanism and fracture design of structural steel, fracture experiments were performed on 25 notched plates. The results indicate that the first crack initiated at the center of notched section which had strong stress triaxiality and expanded towards two sides along the thickness of the plates. The crack is vertical to the direction of load and fracture quickly, the ductility of single-notched plates is higher than those of double-notched ones, and the ductility of thin plates is also higher than those of thick ones. Fracture section is dark gray and has many holes at the center,where the trace of shearing fracture is obviously. Fracture mode is combination of shear and normal fracture and reveals fracture rules. Generally, the data of the experiments are stability and qualitatively reveal fracture rules. Experimental results supply objective evidence to investigate rupture mechanism and fracture design theory of structural steel.
Keywords:structural steel; rupture mechanism; notched plates; initial crack
*国家自然科学基金(50808098)和甘肃省教育厅科研基金(0603-09)。
作者简介：王万祯，博士，副教授，Email：wangwanzhen1975@sina.com。
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