文档介绍：Finite Elements in Analysis and Design 35 (2000) 79}96
Nonlinear "nite element modeling of concrete con"ned
by "posites
Amir Mirmiran! *, h Zagers", Wenqing Yuan!
!Department of Civil and Environmental Engineering, University of Cincinnati, . Box 210071, Cincinnati,
OH 45221-0071, USA
"Walter P. Moore and Associates, 200 South Orange Ave, Suite 1400, Orlando, FL 32801, USA
Abstract
Since use of "posites for con"ning concrete columns is relatively new, analytical models are limited
to those of steel ties and hoops, which tend to overestimate the strength of cross section. A nonlinear "nite
element model with a non-associative Drucker}Prager plasticity is developed to account for restraint
pressure sensitivity of concrete. The predicted stress}strain pare favorably with test results.
Volumetric expansion tendency of con"ned concrete, however, is not preserved. The model shows stress
concentrations around corners of square sections, as previously observed by the experiments. The stress
concentration depends on corner radius. The model, however, does not allow for sti!ness degradation under
cyclic loading. ( 2000 Elsevier Science . All rights reserved.
Keywords: Composites; Concrete; Con"nement; Plasticity; Finite element modeling
1. Introduction
In recent years, use of "ber reinforced polymer (FRP) composites for concrete columns has been
on the rise. The FRP can be used for either retro"t or new construction. Use of "ber-wrapping
technology was "rst practiced on concrete chimneys in Japan [1]. The technique was then extended
to the retro"t of concrete columns. An alternative to "ber-wrapping is the use of pre-formed FRP
half cylinders, which are joined together by applying adhesives on site. The same concept can be
used in new construction of concrete-"lled FRP tube, which works on the same principle of
con"nement. It has been well established that by inhibiting lateral expansion of concrete, .,
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