Shear-dominated deformation (SHDD) is pivotal in sheet metal forming; however, comprehensive modeling of plastic anisotropy in SHDD, specifically shear anisotropy considering both yield stress and plastic flow, has been inadequately addressed in existing literature. In this work, a generalized constitutive framework is introduced on the basis of stress triaxiality-dependent state variable to accurately emulate plastic anisotropy and the physics-based shear constraint in SHDD. The framework is capable to seamlessly integrate with existing yield criteria, preserving computational efficiency and versatility. Notably, the yield function, anisotropic parameters, and their optimization or analytical determination for the non-shear deformation state remain unaltered. When integrated with the Hill48 yield function, featuring either one or two anisotropic parameters within the generalized constitutive framework, precise characterization of yield strength and plastic flow in SHDD is achieved. The applicability of the framework extends to various anisotropic yield functions such as the widely employed Yld2k-2d and the sixth-order polynomial (Poly6) function as a class of associated flow rule-based yield functions, and one non-quadratic yield function for non-associated flow rule scenarios. Experimental validation with two engineering sheet metals, high-strength dual-phase steel DP980 and high-strength aluminum alloy AA7075-T6, was conducted. Comparative analyses with several recently proposed yield criteria, especially Poly6–18p, highlighted the efficiency of the proposed constitutive framework. Furthermore, this study explores intrinsic shear constraints, particularly the absence of through-thickness strains under in-plane shear stress. Additionally, it offers an enhanced description of plastic anisotropy in shear yield stress within the general framework, providing valuable insights into the complexities of SHDD.

中文翻译：

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通用的、计算通用的塑性模型框架 - 第二部分：以剪切各向异性为重点的理论和验证


剪切主导变形 （SHDD） 在钣金成型中至关重要;然而，SHDD 中塑性各向异性的综合建模，特别是考虑屈服应力和塑性流动的剪切各向异性，在现有文献中没有得到充分解决。在这项工作中，在应力三轴相关状态变量的基础上引入了广义本构框架，以准确模拟 SHDD 中的塑性各向异性和基于物理的剪切约束。该框架能够与现有的良率标准无缝集成，从而保持计算效率和多功能性。值得注意的是，屈服函数、各向异性参数及其对非剪切变形状态的优化或解析确定保持不变。当与 Hill48 屈服函数集成时，在广义本构框架内具有一个或两个各向异性参数，可实现 SHDD 中屈服强度和塑性流动的精确表征。该框架的适用性扩展到各种各向异性屈服函数，例如广泛使用的 Yld2k-2d 和六阶多项式 （Poly6） 函数作为一类基于关联流规则的屈服函数，以及一个用于非关联流规则场景的非二次屈服函数。用高强度双相钢 DP980 和高强度铝合金 AA7075-T6 两种工程钣金进行了实验验证。与最近提出的几个产量标准，特别是 Poly6-18p 的比较分析，突出了所提出的本构框架的效率。此外，本研究还探讨了内禀剪切约束，特别是在面内剪切应力下不存在全厚度应变。 此外，它还在一般框架内提供了对剪切屈服应力中塑性各向异性的增强描述，为了解 SHDD 的复杂性提供了有价值的见解。