Anisotropic-Asymmetric Yield Criterion and Anisotropic Hardening Law for Composite Materials: Theory and Formulations

• Published in: Fibers and polymers Vol. 7; no. 1; pp. 42 - 50
• Main Authors: Ji Hoon Kim, Myoung Gyu Lee, Kwan Soo Chung, Jae Ryoun Youn, Tae Jin Kang
• Format: Journal Article
• Language: Korean
• Published: 한국섬유공학회 30.03.2006
• Subjects: Anisotropy; Asymmetry; Constitutive equations; Drucker-Prager yield criterion; Fiber reinforced composites; Fiber reinforced composites; Drucker-Prager yield criterion; Asymmetry; Anisotropy; Constitutive equations
• ISSN: 1229-9197; 1875-0052

In this paper, elasto-plastic constitutive equations for highly anisotropic and asymmetric materials are developed and their numerical implementation is presented. Some engineering materials such as fiber reinforced composites show different material behavior in the different material directions (anisotropy) as well as in tension and compression (asymmetry). Although these materials have mostly been analyzed using the anisotropic elastic constitutive equations, the necessity of consideration of plastic properties has been frequently reported in the previous works. In order to include both the anisotropic and asymmetric properties of composite materials, the Drucker-Prager yield criterion is modified by adding anisotropic parameters and initial components of translation. The implementation procedure for the developed theory and algorithms is presented based on the implicit finite element scheme. The measured data from the previous work are used to validate the present constitutive equations.