Localizing gradient damage model coupled to extended microprestress-solidification theory for long-term nonlinear time-dependent behaviors of concrete structures

• Published in: Mechanics of materials Vol. 154; p. 103713
• Main Authors: Tong, Teng, Hua, Gang, Liu, Zhao, Liu, Xiaofan, Xu, Tengfei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2021
• Subjects: Gradient-enhanced; Microprestress; Nonlocal damage; Solidification; Microprestress; Gradient-enhanced; Nonlocal damage; Solidification
• ISSN: 0167-6636; 1872-7743
• DOI: 10.1016/j.mechmat.2020.103713

A nonlocal damage-based model is proposed to predict the nonlinear long-term deformation of concrete structures, which couples the localizing gradient-enhanced damage (LGED) model for crack nucleation and propagation to the extended microprestress-solidification (XMPS) theory for creep and shrinkage deformations. The proposed LGED-XMPS model circumvents damage localization by incorporating higher-order deformation gradients, and connects creep and shrinkage to inherent moisture transport and heat transfer processes. For creep part, a solidifying Kelvin chain is adopted for the rate-type formulation, which greatly reduces computational burdens of the conventional integral-type formulation. The LGED-XMPS model regularizes mesh-sensitivity of creep deformation intertwined with damage and cracking, which is rarely reported elsewhere. Furthermore, the model are validated with several tests reported in literatures. Specifically, the time-to-failure of concrete specimens subject to high level stresses is well predicted, along with the long-term deflections of simply-supported beams affected by crack growths. It is highlighted that the model is competitive for predicting nonlinear long-term deformation of creep- and crack-sensitive structures. •A nonlocal damage-based model is proposed for modeling long-term time-dependent deformation and crack growths.•The model is implemented in Abaqus with subroutines UEL and UMAT.•The model is suitable for creep- and cracking-sensitive concrete structures.