TC11钛合金应变率相关力学行为的实验和本构模型

发布时间：2018-05-30 11:49

本文选题：钛合金 + 应变率　；参考：《中国有色金属学报》2017年07期

【摘要】：利用MTS、中应变材料试验机和分离式霍普金森拉杆获得TC11钛合金在应变率1×10~(-3)~1×10~3 s~(-1)范围内的应力-应变曲线,利用金相显微镜和扫描电子显微镜观察材料组织和断口形貌,基于修正的Johnson-Cook本构模型进行不同应变率下拉伸力学行为的有限元数值模拟。结果表明:TC11的初始屈服行为表现出明显的应变率强化特性,在中应变率范围内呈现出应变率不太敏感向应变率敏感的转折现象,材料的应变硬化率随着应变率的提高而逐渐降低。TC11的α晶和片层α+β束被拉长,呈现韧性断裂机制。修正Johnson-Cook模型计及应变率对初始屈服应力和应变硬化行为的不同影响,数值计算曲线与试验曲线吻合较好,能够较好地应用于TC11应变率相关力学行为的数值仿真。
[Abstract]:The stress-strain curves of TC11 titanium alloy were obtained by using MTS, medium strain material tester and split Hopkinson rod in the strain rate range of 1 脳 10 ~ (3) ~ (3) ~ (-1). The microstructure and fracture morphology of the alloy were observed by metallographic microscope and scanning electron microscope. Based on the modified Johnson-Cook constitutive model, the finite element numerical simulation of tensile mechanical behavior at different strain rates is carried out. The results show that the initial yield behavior of TC11 shows obvious strain-rate strengthening characteristics, and the strain rate is less sensitive to strain rate-sensitive in the range of mid-strain rate. The strain hardening rate of the material decreases with the increase of strain rate. The 伪 -crystal and lamellar 伪尾 beam of TC11 are elongated, showing a ductile fracture mechanism. The modified Johnson-Cook model takes into account the different effects of strain rate on the initial yield stress and strain hardening behavior. The numerical calculation curve is in good agreement with the experimental curve and can be applied to the numerical simulation of TC11 strain rate-related mechanical behavior.
【作者单位】：中国工程物理研究院总体工程研究所;中国科学院材料力学行为和设计重点实验室中国科学技术大学近代力学系;
【基金】：国家自然科学基金项目(11172288)~~
【分类号】：TG146.23

【相似文献】