中文摘要：

针对金属棒料低应力分离过程中裂纹萌生扩展速率低的问题,提出一种基于双频振动的加载方法,探究带V形槽7A09铝合金棒料的断裂行为。研究了双频振动对带V形槽金属棒料裂纹萌生扩展的作用机理,通过研发双频激振装置,对带V形槽7A09铝合金棒料进行了实验研究。实验结果表明,相对于单频振动加载方法,双频振动载荷能够大幅缩短带V形槽7A09铝合金棒料的分离时间,有效提高裂纹萌生扩展的速率与稳定性,棒料断面几何精度高。

英文摘要：

Aiming at problems of low crack initiations and propagation rates in low stress separation processes of metal bars,a new method was proposed based on double frequency vibrations.This method was used to explore the fracture behaviors of 7A09 aluminum alloy bars with V-shape notchs.The mechanism of double-frequency vibrations on the crack initiations and expansions of V-shaped metal bars was given.Experiments of the V-shaped groove 7A09 aluminum alloy bars were carried out by developed dual-frequency exciting device.Experimental results show that compared with the single frequency vibration loading method,double frequency vibration load may shorten separation time of 7A09 aluminum alloy bars with V-shape notchs significantly,improve the crack initiation rates and stability of the expansion effectively,also the bar section geometric accuracy is high.