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Development and verification of a constitutive approach for the determination of high-strain-rate flow curves by means of the cutting process

通过切削过程确定高应变率流动曲线的本构方法的开发和验证

基本信息

批准号：
365204822
负责人：
Professor Dr.-Ing. Thomas Bergs, since 7/2019
金额：
--
依托单位：
Werkzeugmaschinenlabor - WZL
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/365204822?language=en
关键词：
Development verification constitutive approach determination

项目摘要

The benefit of the FE-simulation for the analysis, design and optimization of metal cutting processes is undisputed, especially in the development of costly and time-intensive tool concepts. Furthermore, it is increasingly used not only in basic research works but also from medium-sized companies to improve the efficiency of product development. In order to simulate real machining processes with FE codes, a reliable constitutive material law is required. This must be capable to exactly describe the thermo-mechanical material flow behavior at extremely high strains (1-5), strain rates (10^-3 - 10^6 1/s) and temperatures (Thomologe = 0.16 to 0.90). For the determination of high-strain-rate flow curves, which are essential for the development of constitutive material laws, special material testing methods are generally used. This includes, for example, the use of the Split Hopkinson Bar Testing (SHBT). SHPT, specially developed for high-strain-rate deformations, is based on the elastic wave theory and can maximum strain rates up to 10^4 1/s. The achieved strain rates with the SHBT are by two orders of magnitude smaller than those in the cutting process. Therefore, the material law must be extrapolated to higher strain rates for the FE-cutting simulation, whereby the cutting material behaviour cannot be adequately reproduced. In addition, the SHBT technique is very complicated, cost-intensive and time consuming. The objective of this research work is, based on the Oxley shear zone theory, the FE cutting simulation and the inverse modeling the development, validation, and supply of a simple and economical constitutive approach to determine high-strain-rate flow curves (>10^4 1/s) directly from the cutting process. To verify the approach to be developed, different materials are to be considered.

有限元仿真在金属切削过程分析、设计和优化方面的优势是毋庸置疑的，尤其是在开发成本高、耗时长的刀具概念方面。此外，它不仅越来越多地用于基础研究工作，而且也越来越多地用于中型公司，以提高产品开发效率。为了用有限元程序模拟真实的加工过程，需要可靠的材料本构关系。这必须能够准确描述在极高应变（1-5）、应变速率（10^-3 - 10^6 1/s）和温度（ε = 0.16至0.90）下的热机械材料流动行为。为了确定高应变率流动曲线，这是必不可少的本构材料定律的发展，特殊的材料测试方法通常使用。例如，这包括使用分离式霍普金森杆测试（SHBT）。SHPT是专门为高应变率变形而开发的，基于弹性波理论，最大应变率可达10^4 1/s。与SHBT实现的应变速率是由两个数量级小于那些在切削过程中。因此，材料定律必须外推到更高的应变率FE切削模拟，从而不能充分再现切削材料的行为。此外，SHBT技术非常复杂，成本高且耗时。本研究工作的目的是，基于奥克斯利剪切带理论，有限元切削模拟和逆建模的发展，验证，并提供一个简单和经济的本构方法来确定高应变率流动曲线（>10^4 1/s）直接从切削过程。为了验证将要开发的方法，需要考虑不同的材料。