Mesomechanical modeling of debonding failures in FRP-strengthened structures

Debonding mechanisms in FRP-strengthened structures have been the subject of numerous investigations. Most of the modeling studies conducted thus far are based on the assumption of macroscopic relationships between local interfacial stresses and local relative displacements between FRP and substrate. Such laws are calibrated experimentally and incorporated in structural models with the purpose of determining macroscopic quantities of design interest. This approach presents a number of limitations, as macroscopic interfacial laws spatially homogenize complex damage and failure processes taking place at the lower scales. This paper proposes an alternative approach to the problem of FRP debonding, based on a mesomechanical analysis including explicit description of the interfacial geometry, and illustrates the first steps taken by the authors in this direction. The final goal is to be able to design and optimize the macroscopic interfacial behavior by tailoring the features at the lower scale. Also, a deeper understanding of mixed-mode interfacial failures is aimed at. The paper illustrates the basic idea, the main details about the current implementation, and preliminary numerical results.

[1]  M. Tabbara,et al.  RANDOM PARTICLE MODEL FOR FRACTURE OF AGGREGATE OR FIBER COMPOSITES , 1990 .

[2]  A. Hillerborg,et al.  Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements , 1976 .

[3]  Carsten Könke,et al.  Mesoscale modeling of concrete: Geometry and numerics , 2006 .

[4]  C. A. Tang,et al.  Mesomechanical model for concrete. Part II : applications , 2004 .

[5]  C. A. Tang,et al.  MESOMECHANICAL MODEL FOR CONCRETE. PART I: MODEL DEVELOPMENT , 2004 .

[6]  Hamid Sadouki,et al.  Simulation and analysis of composite structures , 1985 .

[7]  Z. M. Wang,et al.  Mesoscopic study of concrete I: generation of random aggregate structure and finite element mesh , 1999 .

[8]  P. Wriggers,et al.  Mesoscale models for concrete: homogenisation and damage behaviour , 2006 .

[9]  Luc Taerwe,et al.  Random particle model for concrete based on Delaunay triangulation , 1993 .

[10]  J. Molinari,et al.  Influence of the meso-structure in dynamic fracture simulation of concrete under tensile loading , 2011 .

[11]  Philippe H. Geubelle,et al.  Multiscale cohesive failure modeling of heterogeneous adhesives , 2008 .

[12]  H. Schorn,et al.  Numerical simulation of crack propagation from microcracking to fracture , 1991 .

[13]  Gilles Pijaudier-Cabot,et al.  Damage Models for Concrete , 2001 .

[14]  J. Mier,et al.  Simple lattice model for numerical simulation of fracture of concrete materials and structures , 1992 .