【摘要】 采用准连续介质力学的数值方法,模拟了单晶铜纳米压痕试验中的初始塑性变形过程,获得了压头在不同压深时的载荷-压深的加载和卸载曲线,然后根据Oliver-Pharr方法计算出压头在不同压深时单晶铜的接触刚度、纳米硬度,并将获得的计算结果与相关文献的试验结果相比较。研究发现:单晶铜的接触刚度-位移曲线呈线性关系,纳米硬度-位移曲线存在尺寸效应现象,计算获得的纳米硬度值为0.755±0.027Gpa,这些结果与文献中实验获得的结果非常吻合,表明使用该方法预测材料纳米硬度是非常有效、正确和可行的。更多还原

【Abstract】 Quasicontinuum simulations were performed to study the feature of plastic deformation in the initial stage of nanoindentation test of single crystal copper by using rigid cylindrical indenter.The corresponding load-depth loading and unloading curves at different depths were obtained.The contact stiffness and nanohardness of single crystal copper at different depths were calculated by Oliver-Pharr method.The calculated results of using quasicontinuum method were compared with nanoindentation experiments published.The results show that the contact stiffness-displacement relations of single crystal copper are linear.The simulated results indicate that the size effect phenomenon exist in nanohardness measurement of single crystal copper.The nanohardness of single crystal copper is 0.755±0.027Gpa.The results agree with the nanoindentation experiments,indicating that it is reliable and valid to measure the nanohardness by using the quasicontinuum method.更多还原