当前位置: X-MOL 学术J. Mater. Process. Tech. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
On the experimental characterization of sheet metal formability and the consistent calibration of the MK model for biaxial stretching in plane stress
Journal of Materials Processing Technology ( IF 6.3 ) Pub Date : 2021-01-01 , DOI: 10.1016/j.jmatprotec.2020.116887
C. Butcher , F. Khameneh , A. Abedini , D. Connolly , S. Kurukuri

Abstract Analytical formability models based upon in-plane proportional plane stress loading such as the Marciniak–Kuczynski (MK) model are commonly evaluated against forming limit curves (FLCs) obtained using Nakazima tests with out-of-plane deformation, non-linear strain paths and tool contact. The present study has conducted a comprehensive experimental characterization of a DP1180 advanced high strength steel with relatively low formability to demonstrate that the use of Nakazima FLC data can lead to a physically inconsistent MK model. Although good agreement can be obtained using the MK model with Nakazima data, it is attributed to calibration bias in the hardening model and selection of the imperfection factor. Marciniak tests should be performed to characterize the FLC or process-corrections be applied to the Nakazima FLC to then calibrate the MK imperfection factor. An analysis of the MK framework reveals a false dependence of the imperfection factor on the hardening model due to artefacts in the hardening model calibration. When the Considere constraint for the uniform elongation is imposed during the hardening model calibration, the MK imperfection factor becomes nearly independent of the choice of hardening model. The accuracy of the FLC predicted by the MK model, when appropriately constrained and calibrated in a deterministic manner, was in a reasonable agreement with the experimental data only after accounting for material anisotropy. In contrast, the deterministic Modified Maximum Force Criterion (MMFC) model provided a very close estimate of the experimental forming limit strains of the mildly anisotropic DP1180 using both isotropic and anisotropic yield functions.

中文翻译:

关于钣金成形性的实验表征和平面应力双轴拉伸 MK 模型的一致校准

摘要 基于平面内比例平面应力加载的解析成形性模型,例如 Marciniak-Kuczynski (MK) 模型,通常根据使用 Nakazima 测试获得的成形极限曲线 (FLC) 进行评估,该曲线具有平面外变形、非线性应变路径和工具接触。本研究对成形性相对较低的 DP1180 高级高强度钢进行了全面的实验表征,以证明使用 Nakazima FLC 数据会导致物理上不一致的 MK 模型。尽管使用 MK 模型与 Nakazima 数据可以获得良好的一致性,但这归因于硬化模型中的校准偏差和缺陷因子的选择。应该执行 Marciniak 测试来表征 FLC 或对 Nakazima FLC 应用过程校正,然后校准 MK 缺陷系数。对 MK 框架的分析揭示了由于硬化模型校准中的人工制品,缺陷因子对硬化模型的错误依赖。当在硬化模型校准期间对均匀伸长率施加考虑约束时,MK 缺陷因子变得几乎与硬化模型的选择无关。MK 模型预测的 FLC 的准确性,当以确定性方式进行适当约束和校准时,仅在考虑材料各向异性后才与实验数据合理一致。相比之下,
更新日期:2021-01-01
down
wechat
bug