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对螺栓力学性能做出规定的ISO 898-1中规定,为了测得拉伸强度Rm,用制品或者由制品切削加工出来的光滑试样进行拉伸试验,但在螺纹应力计算时用到的有效截面面积As的值往往成为问题。还有,对于正在修订审议中的ISO/CD 898-1:2005准备追加测定制品屈服强度以及断裂伸长率的试验方法,其关于试验条件和特性值的定义的妥当性尚未充分讨论。在本研究工作中,对两种尺寸(M10×1.25和M8)及两个强度级别(8.8和12.9)的螺栓,用制品和光滑试样进行拉伸试验,将得到的结果与弹塑性FEM分析的结果做比较,考察自由螺纹部分对拉伸性能的影响。
The provisions of the mechanical properties of the bolt ISO 898-1 provides that, in order to measure the tensile strength Rm, with products or products from the smooth processing of samples for tensile test, but the thread stress used in the calculation of effective The value of the cross-sectional area As often becomes a problem. Also, the validity of the definitions of test conditions and characteristic values for the test method for preparing the additional test for yield strength and elongation at break of ISO / CD 898-1: 2005 under revision is not fully discussed. In this study, tensile tests were performed on two types of bolts (M10 × 1.25 and M8) and two strength classes (8.8 and 12.9) using a product and a smooth specimen. The results obtained were compared with the elasto-plastic FEM analysis The results of the comparison to examine the freedom of the threaded part of the tensile properties.