金属薄板十字拉伸试验设计关键技术

对金属薄板十字拉伸试验机及其试样设计关键技术进行了总结,采用Abaqus软件对3种经典试样在相同和不同加载比下的应力分布及塑性变形区范围进行了比较分析.结果表明,十字拉伸试验机要满足试样中心区的偏移可控,减少附加弯矩及确保加载的协调控制;十字拉伸试样的设计要求增加试样中心区的塑性变形量及其均匀应力场的范围,降低应力集中.所分析的3个试样中,Kuwabara试样应力均匀性最差,Mankinde试样中心区应力均匀性最好,Müller试样具有应力集中最小、塑性变形区最小及其塑性区范围随加载比改变变化明显的特点.

Key Technologies for Sheet Metal Cruciform Tensile Experiments Design

The paper presents a summary of the key technologies for the design of a cruciform biaxial tensile machine and specimen. The Abaqus software is resorted to a comparative study of the stress distribution and plastic strain range of three classic specimens under the same loading ratio and different loading ratios. Study results show that the movement of the central region of specimen under control is a guarantee. A minimized extra bending momentum is a need, and a cooperation of loadings for different directions is a must. To increrase the plastic deformation in the central region and enlarge the uniform stress field range as well as to diminish the stress concentration are critical for the design of a specimen. Of the three specimens being analyzed, Kuwabara specimen is of the worst stress uniformity; the Mankinde specimen is of the best stress uniformity; Müller specimen is of the least stress concentration and the smallest plastic deformation region. And the plastic deformation in Müller specimen is more sensitive to the change of the load ratio.