钛合金电致塑性本构方程及多物理场耦合分析
Analysis of Electroplastic Constitutive Equation and Multi-physical Field Coupling of Titanium Alloy
韩建超 1张孟非 2王斌 3国生辉 4贾燚 4王涛4
作者信息
- 1. 太原理工大学机械与运载工程学院 太原 030024;太原理工大学先进金属复合材料成形技术与装备教育部工程研究中心 太原 030024;海安太原理工先进制造与智能装备产业研究院 海安 226600
- 2. 太原理工大学机械与运载工程学院 太原 030024;太原理工大学先进金属复合材料成形技术与装备教育部工程研究中心 太原 030024;北京星航机电装备有限公司 北京 100074
- 3. 北京星航机电装备有限公司 北京 100074
- 4. 太原理工大学机械与运载工程学院 太原 030024;太原理工大学先进金属复合材料成形技术与装备教育部工程研究中心 太原 030024
- 折叠
摘要
脉冲电流激发的电致塑性效应能够显著提高钛合金的成形能力,而电塑性效应是融合"电-热-结构"多物理场综合作用的结果,构建电辅助有限元模型对于分析其塑性变形行为及优化成形工艺参数具有重要意义.以Ti-6Al-4V合金为研究对象进行不同电流密度、温度及应变速率下的电辅助拉伸试验;基于Johnson-Cook模型建立一个考虑热效应与非热效应的本构模型,其相关系数R2均高于0.95,平均相对误差低于2％;基于此模型对电脉冲辅助拉伸过程中物理场进行有限元分析,当电流密度为4.19 A/mm2时,随着试样拉伸至颈缩,电流密度相较于初始值升高21.96％,导致标距段内温度梯度明显增大,温差由68.69 ℃增至95.52 ℃,与同温度350 ℃高温试验相比,在应变场上表现为整体均匀程度降低,由于非热效应的作用峰值应力降低了 49 MPa,模型预测的应力-应变结果与试验数据相比呈现较高的拟合精度,为进一步研究电辅助成形工艺及电致塑性机理提供了理论方法.
Abstract
The electroplastic effect stimulated by pulse current can significantly improve the forming ability of titanium alloys.However,the electroplastic effect is the result of the comprehensive action of"electric-thermal-structural"multi-physical fields,and the construction of an electrically assisted finite element model is of great significance for analyzing the plastic deformation behavior and optimizing the forming process parameters.Conducting electric pulse-assisted stretching experiments on Ti-6Al-4V alloy under different current densities,temperatures,and strain rates.Based on the Johnson-Cook model,a constitutive model considering the thermal and athermal effects is established,with the correlation coefficient R2 higher than 0.95 and the average relative error lower than 2％.Based on this model,the finite element method analyzes the physical field in the process of electric pulse-assisted stretching.When the current density is 4.19 A/mm2,the current density increased by 21.96％compared with the initial value as the specimen stretched to necking,which led to an obvious increase in the temperature gradient in the gauge section,and the temperature difference increased from 68.69 ℃ to 95.52 ℃.Compared with the high-temperature test at the same temperature of 350 ℃,the overall uniformity in the strain field is reduced,and the peak stress is reduced by 49 MPa due to the athermal effect.The stress-strain results predicted by the model show a high fitting accuracy compared to the experimental data.It provides a theoretical method for further study of the electro-assisted forming process and electroplastic effect mechanism.
关键词
钛合金/电致塑性效应/电辅助本构方程/多物理场耦合建模Key words
titanium alloy/electroplastic effect/electrically assisted constitutive equation/multi-physical field coupling modeling引用本文复制引用
基金项目
国家自然科学基金(52275362)
国家自然科学基金(51904205)
山西省基础研究计划优秀青年培育(202203021224003)
中央引导地方科技发展资金(YDZJSX2021A020)
中央引导地方科技发展资金(YDZX20191400002149)
出版年
2024
NETL
NSTL
万方数据