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一前言材料的持久极限σ_R是构件疲劳设计中必须考虑的重要数据之一。但目前按常规方法测定材料的持久极限,需要化费大量的试件和时间。因此,研究σ_R的快速测定,已成为人们普遍关注的问题。近几年新兴的损伤力学,为疲劳研究提供了新的理论依据。本文从疲劳损伤演变方程导出的破断寿命公式出发,得到了计算材料持久极限的公式。只要在二个应力水平下做小量试件的疲劳试验,就可得出比较满意的结果。为了检验这一方法的精确性和优越性,作了A3钢旋转弯曲下的疲劳试验。结果表明:用常规法和本文方法得出的σ_(-1)相当吻合。
A Preamble Material endurance limit σ_R is one of the important data that must be considered in fatigue design of components. At present, however, the long-term limit of the material is determined according to a conventional method, which requires a large amount of specimen and time to be spent. Therefore, to study the rapid determination of σ_R has become a common concern. Emerging damage mechanics in recent years provide a new theoretical basis for fatigue research. In this paper, the formula for calculating the endurance limit of materials is derived from the formula of the rupture life derived from the evolution equation of fatigue damage. As long as two stress levels to do a small amount of fatigue test specimens, you can come to more satisfactory results. In order to test the accuracy and superiority of this method, a fatigue test of A3 steel under rotational bending was made. The results show that the σ _ (- 1) obtained by this method is in good agreement with the conventional method.