基于GTN模型的含缺陷球墨铸铁力学行为分析

Analysis of Mechanical Behavior of Ductile Iron with Defects Based on GTN Model

利用有限元反向标定法得到Gurson-Tvergaard-Needleman(GTN)损伤模型的参数,并基于GTN模型模拟含缺陷QT500球墨铸铁的单轴拉伸变形过程,提出了描述材料内部缩松分散度的正态分布函数,以描述其对力学性能的影响。结果表明,GTN损伤模型可准确地反映球墨铸铁材料的损伤演化。随着孔隙率分布函数方差的增大,孔隙率的分布变广,使材料承载性能下降。

The parameters of the Gurson-Tvergaard-Needleman(GTN)damage model were obtained by using the finite element reverse calibration method.Based on the GTN model,the uniaxial tensile deformation process of QT500 ductile iron with defects was simulated,and the normal distribution function describing the internal shrinkage dispersion of the material was proposed to describe its effect on mechanical properties.The results show that GTN damage model can accurately reflect the damage evolution of ductile iron materials.As the variance of the porosity distribution function increases,the porosity distribution widens,and the bearing capacity of materials decreases.