ON ISOTROPIC AND ANISOTROPIC UNILATERAL DAMAGE MODEL FOR CONCRETE
In this contribution a unified isotropic and anisotropic damage model is proposed and then applied to concrete modeling. The increases of the intrinsic secant compliance under the purely positive and purely negative stresses are adopted as the internal damage variables, and the hypothesis of strain equivalence or strain energy equivalence is no longer required. To consider the unilateral effects, new consistent positive and negative projection operators are employed, and the secant constitutive relation is then established within the framework of irreversible thermodynamics. The rate formulations and the corresponding tangent stiffness are also de-rived, which can be employed to develop the multisurface return mapping algorithm. As examples, the isotropic, orthotropic and fully anisotropic evolution laws for the increased secant compliances are presented to exemplify the presented unified damage model. The proposed model and the fully anisotropic damage evolution laws are finally verified with numerical applications to concrete modeling, demonstrating the capability of describing most of the nonlinear performances of concrete, such as strength softening, stiffness degradation, decays of strength due to the lateral tensile stress, strength and ductility enhancement under lateral compressive confinement, unilateral effects and damage induced anisotropy.
Concrete constitutive modelling damage mechanics unilateral effects
J. Y. Wu
Department of Civil Engineering State Key Laboratory of Subtropical Architecture Science, South China University of Technology, Guangzhou, China
国际会议
上海
英文
360-371
2007-11-28（万方平台首次上网日期，不代表论文的发表时间）