This research experimentally determines the Gurson-Tvergaard-Needleman (GTN) model damage mechanics parameters for 6061 Al alloys. Five different heat treatment conditions including T4 (natural aging) and T6 (peak strength) conditions of 6061 Al alloy were investigated. The GTN parameters considering different heat treatment conditions of the alloy were obtained by tensile tests. Scanning electron microscope (SEM) micrographs were used as inputs to determine initial and nucleated volume fractions. SEM and energy dispersive X-ray spectrography (EDX) analyses also revealed that the second-phase precipitates are the origin of the incipient voids. SEM analyses enabled the fractographic investigations where the primary and secondary voids were exhibited and thus showing nucleation strain. Density measurements clarify the critical and final void volume fractions and the standard deviation of the nucleated void volume fraction distribution. The results show that the void volume fraction increases exponentially along with increasing effective tensile plastic strain. Hence, a total of six different GTN parameters have been identified experimentally. Finite element method simulations based on GTN damage model were performed to verify the GTN model parameters. The results show that the experimentally obtained GTN model parameters could be used when performing tensile deformation simulations of 6061 Al alloys fabricated with different heat treatment conditions.

这项研究通过实验确定了6061铝合金的Gurson-Tvergaard-Needleman（GTN）模型损伤力学参数。研究了5种不同的热处理条件，包括6061铝合金的T4（自然时效）和T6（峰值强度）条件。通过拉伸试验获得考虑了合金的不同热处理条件的GTN参数。扫描电子显微镜（SEM）显微照片用作确定初始和有核体积分数的输入。SEM和能量色散X射线光谱（EDX）分析还显示，第二相沉淀物是初期空隙的起源。SEM分析使得能够进行分形研究，其中主要和次要空隙均被显示，从而显示出形核应变。密度测量澄清了关键和最终空隙体积分数以及有核空隙体积分数分布的标准偏差。结果表明，空隙体积分数随着有效拉伸塑性应变的增加而呈指数增加。因此，实验上已经确定了总共六个不同的GTN参数。进行了基于GTN损伤模型的有限元方法仿真，以验证GTN模型参数。结果表明，在对采用不同热处理条件制造的6061铝合金进行拉伸变形模拟时，可以使用实验获得的GTN模型参数。结果表明，空隙体积分数随着有效拉伸塑性应变的增加而呈指数增加。因此，实验上已经确定了总共六个不同的GTN参数。进行了基于GTN损伤模型的有限元方法仿真，以验证GTN模型参数。结果表明，在对不同热处理条件下制造的6061铝合金进行拉伸变形模拟时，可以使用实验获得的GTN模型参数。结果表明，空隙体积分数随着有效拉伸塑性应变的增加而呈指数增加。因此，实验上已经确定了总共六个不同的GTN参数。进行了基于GTN损伤模型的有限元方法仿真，以验证GTN模型参数。结果表明，在对不同热处理条件下制造的6061铝合金进行拉伸变形模拟时，可以使用实验获得的GTN模型参数。