基于液压鼓胀试验的材料冲击韧性评价方法的研究

Study on Evaluation Method for Material Impact Toughness Based on Hydraulic Bulging Test

提出了一种基于微试样的评价材料韧性的方法——裂纹法。利用液压鼓胀试验技术通过液压加压使试样发生变形直至试样破坏。试样的韧性取决于液压鼓胀试验的载荷-位移曲线和试样爆破后试样的几何形状。引入裂纹长度和裂纹最大扩展量以描述爆炸试样的几何形状,给出在不同裂纹情况下这两个参量的测量方法。根据载荷-位移曲线计算试样形变能,然后根据爆破试样的几何参数进行修正,并用经验关联式计算断裂能的冲击韧性。

In this paper, a method tot evaluating the toughness of materials based on micro-specimen was in- troduced, which has hydraulic bulging testing technique used to pressurize the specimen till it＇s deformed and destroyed. The toughness of the specimen depends on the pressure-displacement curve of the hydraulic bulging test and the geometry of the specimen after the burst. Two parameters of the total crack length and the maximum range of crack were introduced to describe the geometry of the burst specimen and the method to measure two parameters under various cracks presented. Through basing on the pressure-displacement curves and the parameters revised from the geometry of the burst specimen and the empirical correlation, the impact toughness of fracture energy was calculated. Testing and verifying this method in tour different steels demonstrates that, making use of the hydraulic bulging testing method to get the impact energy is possible.