Necking of anisotropic micro-films with strain-gradient effects

• 来源期刊: 力学学报(英文版)
• 年，卷（期）: 2008,（5）
• 页码范围: 557-567
• 页数: 11页
• 语种: 英文
• DOI: 10.1007/s10409-008-0186-6

摘要

Necking of stubby micro-films of aluminum is investigated numerically by considering tension of a speci-men with an initial imperfection used to onset localisation. Plastic anisotropy is represented by two different yield cri-teria and strain-gradient effects are accounted for using the visco-plastic finite strain model. Furthermore, the model is extended to isotropic anisotropic hardening (evolving aniso-tropy). For isotropic hardening plastic anisotropy affects the predicted overall nominal stress level, while the peak stress remains at an overall logarithmic strain corresponding to the hardening exponent. This holds true for both local and non-local materials. Anisotropic hardening delays the point of maximum overall nominal stress.