论文部分内容阅读
应变强化指数n值因同时体现金属板料胀形、压延等成形性能优劣,甚至与材料的宏观断裂和疲劳特性也存在一定关系,故已成为评价其冲压成形性能的主要材料参数而获得广泛关注。而幂指型硬化模型的另一重要参数——强化系数K值,前期研究虽表明其对板料的冲压成形性能也有重要影响,但目前对其在冲压成形性方面的研究甚少。文章以金属板料单向拉伸塑性失稳点特性为基础,结合硬化模型在该点附近较好地与板料真实应力-应变曲线相符合的基本假设,详细推导了K值与抗拉强度σb和n值之间解析关系,并基于该解析关系讨论了K值与n值在评价板料成形性能方面的一致性。结果表明,K值可作为衡量板料成形性能的综合指标,为研究金属板料成形能力评价方法打开了新的思路。通过实验证明了该解析结果的正确性及其工程适用性。
The value of strain-hardening index n has also been widely used as the main material parameter to evaluate its stamping formability because of its good formability, such as bulging and calendering of sheet metal, even with the macroscopic rupture and fatigue properties of the material. attention. However, the other important parameter of the power hardening model is the K value of the strengthening coefficient. Although the previous studies have shown that it has an important influence on the stamping formability of sheet metal, little research has been done on its formability. Based on the uniaxial tensile plastic instability point characteristics of sheet metal and the basic assumption that the hardening model is in good agreement with the true stress-strain curve of sheet metal at this point, the relationship between K value and tensile strength σb and n values of the relationship between the analytical, and based on the analytical relationship between the K value and n value in the evaluation of sheet forming performance consistency. The results show that the K value can be used as a comprehensive index to measure the formability of sheet metal, which opens up new ideas for the research on the forming ability evaluation of sheet metal. The correctness of this analytical result and its engineering applicability are proved through experiments.