国产6061-T6铝合金的修正塑性本构模型

铝合金材料已广泛地应用于各种工程结构中。能准确描述铝合金在复杂应力状态下的塑性本构关系,对铝合金结构在复杂工况下的分析和设计具有重要意义。传统的von Mises屈服准则忽略了应力状态对金属塑性的影响,并不适用于复杂应力状态下的铝合金材料。通过试验证明了应力三轴度和Lode角均会对6061-T6铝合金的塑性行为产生影响,并在此基础上提出了适用于国产6061-T6铝合金在复杂应力状态下的塑性本构模型,并校准了全过程硬化规律和新屈服准则。通过试验和数值结果对比可知,该塑性本构模型可以精确地模拟国产6061-T6铝合金在复杂应力状态下的弹塑性行为。

Modified Plasticity Constitutive Model of Chinese 6061-T6 Aluminum Alloy

Aluminum alloy has been widely used in engineering structures. A plasticity constitutive model, which can accurately describe the elastoplastic behavior of aluminum alloy under complicated stress states, is of great significance to the analysis and design of aluminum alloy structures under complicated working conditions. The conventional von Mises yield criterion ignores the effect of stress state on metal plasticity, which is not suitable for aluminum alloy materials in complicated stress states. This paper conducts a series of tests to demonstrate that stress triaxiality and Lode angle can influence the plastic behavior of the 6061-T6 aluminum alloy. Based on the test results, a plasticity constitutive model suitable for 6061-T6 aluminum alloy in complicated stress states is proposed, and the full-range hardening law and the new yield criterion are calibrated, which can accurately simulate the elastoplastic behavior of Chinese structural 6061-T6 aluminum alloy in complicated stress states by comparing the experimental and numerical results.