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变形过程中滞弹性行为引起的弹性模量变化是影响高强钢回弹预测精度的一个重要因素,充分了解并掌握材料的滞弹性行为及弹性模量的变化规律对准确预测高强钢的回弹十分重要。以第三代超高强度钢QP980为研究对象,通过加载-卸载实验研究讨论了QP980滞弹性变形行为。实验结果表明,随真实应变增加,QP980钢板的弦模量不断降低,滞弹性应变的比例不断增加,弦模量和滞弹性应变呈线性关系,材料弦模量和滞弹性应变可以表示为真实应变的指数函数形式;使用抛物线函数对加载-卸载时的滞后环进行建模,进而可以预测在任一应变卸载时,应力应变之间的对应关系。
The change of elastic modulus caused by the anelastic behavior during deformation is an important factor that affects the prediction accuracy of rebound of high strength steel. It is necessary to fully understand and grasp the variation of material’s anelastic behavior and elastic modulus to accurately predict the rebound of high strength steel important. With the third generation of ultra-high strength steel QP980 as the research object, the ancillary elastic deformation behavior of QP980 was discussed by loading-unloading experiment. The experimental results show that with the increase of real strain, the chord modulus of QP980 steel decreases continuously, and the ratio of the anelastic strain increases continuously. The chord modulus and the elastic strain have a linear relationship. The chord modulus and the anelastic strain can be expressed as real strain The parabolic function is used to model the hysteresis loop during load-unload, and then the corresponding relationship between stress and strain at any strain unloading can be predicted.