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采用分子静力学方法结合量子修正的Sutton-Chen多体势研究了含圆孔的纳米薄膜在单向加载过程中的力学行为,并采用共近邻分析方法研究了薄膜的微结构演化过程.模拟结果表明:孔洞的引入显著地降低了纳米薄膜的杨氏模量和屈服应力;在拉伸过程中,孔洞的形状随着应变的增加逐渐由圆形变为椭圆形,最终孔洞闭合;纳米薄膜在进入塑性变形阶段后,薄膜内部出现原子的堆跺层错,这种层错结构的出现是肖克莱不全位错在薄膜内部沿着{111}面的[112]方向运动的结果.
The mechanical behavior of nanofilms with circular pores during uniaxial loading was investigated by using molecular static mechanics and Sutton-Chen multi-body potential with quantum correction. The evolution of microstructure of the films was investigated by co-nearest neighbors method. It is shown that the introduction of voids significantly reduces the Young’s modulus and yield stress of the nanofilm. During the stretching process, the shape of the voids gradually changes from circular to elliptical with the increase of strain, After entering the phase of plastic deformation, the atomic stacking faults occur in the film. The appearance of the fault structure is the result of Shockley’s total dislocation movement in the film along the {111} plane [112].