基于近场动力学方法的多孔材料单轴拉伸断裂韧性研究

Investigation of Fracture Toughness of Porous Materials under Uniaxial Tension Based on Peridynamics Method

摘要:

基于近场动力学方法模拟了单刃缺口多孔材料的单轴拉伸试验，通过与文献数据对比验证了数值模拟方法的有效性，对孔隙率为3%~15%的多孔材料进行模拟，得到了其断裂韧性的变化规律，并分析了其增韧机理.结果表明：在单轴拉伸作用下，多孔材料的断裂韧性随着孔隙率的增加先增大后减小，在孔隙率为12%时达到峰值；在单轴拉伸过程中，局部孔隙吸引导致的主裂纹偏转和次裂纹萌生是多孔材料断裂韧性提升的主要原因.

Abstract:

The uniaxial tension of porous materials with single-edged notch was simulated based on peridynamics method. The validity of the numerical simulation was verified by comparing with the data in the literatures. Based on the simulation of the materials with porosity ranging from 3% to 15%， the variation rule of fracture toughness of porous materials was obtained， and the toughening mechanism of porous materials was proposed. The results show that under the uniaxial tension， the fracture toughness of porous materials increases firstly and then decreases with the increase of porosity， and with a peak value at the porosity of 12%. During uniaxial tensile process， the deflection of primary crack and initiation of secondary crack， which caused by the attraction of local pore system， are the main reasons for the improvement of the fracture toughness of porous materials.