Application of genetic algorithms for optimizing the Johnson-Cook constitutive model parameters when simulating the titanium alloy Ti-6Al-4V machining process

作者：Chen Guang; Ren Chengzu^*; Yu Wei; Yang Xiaoyong; Zhang Lifeng

来源：Proceedings of the Institution of Mechanical Engineers - Part B: Journal of Engineering Manufacture , 2012, 226(B8): 1287-1297.

DOI：10.1177/0954405412447735

• Titanium alloy
• Johnson-Cook constitutive model
• optimization
• machining simulation

Finite element simulation of metal machining requires accurate constitutive models to characterize the material stress-strain response in plastic deformation processes. An optimization methodology using genetic algorithms was developed to determine the Johnson-Cook material model for Ti-6Al-4V alloy. The optimization of the parameters resulted in lower errors between the calculated flow stress and the experimental values obtained through the split Hopkinson pressure bar tests at different temperatures (ranging from 25 degrees C to 900 degrees C) and strain rates (2000 and 2500 s(-1)). Optimized Johnson-Cook constitutive parameters were used to calculate the flow stress under various conditions. The calculated results showed excellent agreement with the experimental values, with errors lower than 4%. In addition, Ti-6Al-4V alloy orthogonal cutting experiments were carried out to validate the finite element simulation results. The experimental chip morphology was compared with the simulation results obtained by the optimized Johnson-Cook model (M2) and the original Johnson-Cook model (M1). The simulated results (including chip morphology and cutting force) were affected by the flow stress model. Comparison of the experimental and simulated results revealed that the optimized Johnson-Cook model can provide relatively good prediction results for the titanium alloy machining process, especially for chip morphology prediction.

• 出版日期2012-8
• 单位天津大学