预测铝合金单轴力学性能的复合型双锥压入法

Composite Dual-conical Indentation Method for Predicting the Uniaxial Mechanical Properties of Aluminum Alloys

锥形压入作为一种发展较早的压入测试手段,可在一定范围内实现材料单轴力学性能的唯一获取,但目前仍存在稳定性和简便性等方面的缺陷。为避免传统锥形压入需要两个或以上压头分别压入不同位置且压点之间存在匹配性等问题,创新地设计和使用了复合型双锥压头。基于能量等效原理建立了锥形压入的弹塑性加载模型,并通过较大范围的数值计算验证了该模型的准确性。通过关联复合型双锥压入与单锥压入的响应曲线,发展了一种复合型双锥压入方法(Composite dual-conical indentation method,CDIM)。针对3种铝合金,利用复合型压入试验获得了稳定的载荷-深度曲线,并结合CDIM预测了材料的单轴应力-应变曲线。结果表明,复合型压入预测结果与单轴拉伸结果较为一致。

Conical indentation, as an early developed indentation test method, can uniquely acquire the uniaxial mechanical properties of materials within a certain range, but there are still defects in stability and simplicity. In order to avoid the problems that the traditional dual-conical indentation requires two indenters to penetrate different positions respectively and the compatibility between the indentation points, a composite dual-conical indenter is innovatively designed and used. Based on equivalent energy principle, an elastic-plastic loading model for conical indentation is established and its accuracy is verified via a large range of numerical simulations. By correlating response curves of composite dual-conical indentation and single-conical indentation, a composite dual-conical indentation method(CDIM) is developed. For three kinds of aluminum alloys, the stable load-depth curves are obtained by the composite indentation tests, and the uniaxial stress-strain curves are predicted by CDIM. The results show that the predictions of CDIM are consistent with those from uniaxial tension.