(to be submitted for journal publication)
K.M. Mosalam,
Department of Civil and Environmental Engineering, University of California, Berkeley,
CA 94720, U.S.A.
G.H. Paulino,
Department of Civil and Environmental Engineering, University of Illinois
at Urbana-Champaign,Newmark
Laboratory, 205 North Mathews Avenue,
IL 61801, U.S.A.
Abstract
The fixed smeared crack concept with strain decomposition is employed to carry non-linear
finite element simulations of either unreinforced or reinforced concrete structures.
In general, such solutions show spurious mesh dependence, and a remedy to alleviate this
problem consists of adapting the finite element mesh to the present level of damage
(cracking) in space and (pseudo-)time. Thus, the element size is determined in a
manner consistent with the nature of the deformation process. Upon such automated
adjustment of the finite element size, a simple rule for the crack bandwidth (e.g.
proportional to the square root of the area of the element) suffices for capturing damage
evolution. A simple and adaptive technique is presented, which relies on the
"apparent fracture energy density" concept. This analysis framework leads
naturally to a physically-based a posteriori error estimation method using the
super-convergent patch recovery concept and a practical h-refinement procedure. Examples are presented, strengths and limitations of the approach are pointed out, and
potential extensions of this work are discussed.
Key words: nonlinear finite element analysis, smeared cracking, crack band width, fracture energy, error estimation, adaptivity, h-refinement, super-convergent patch recovery (SPR).