Publication Details

Yu, T., Teng, J. G., Wong, Y. L. & Dong, S. L. (2007). Assessment of drucker-prager type plasticity models for predicting the behaviour of FRP-confined concrete. In S. T. Smith (Eds.), Proceedings of the First Asia-Pacific Conference on FRP in Structures: APFIS 2007 (pp. 161-166). Hong Kong: Department of Civil Engineering, University of Hong Kong.


This paper presents a critical assessment of the ability of existing Drucker-Prager (D-P) type plasticity models to predict the behaviour of confined concrete using both experimental observations and a recent analytical model. This assessment shows that for a D-P plasticity model to succeed in predicting the behaviour of FRP-confined and other passively-confined concrete, it needs to possess the following three features: (a) a yield criterion which includes the third deviatoric stress invariant, (b) a hardening/softening rule which is dependent on the confining pressure; and (c) a flow rule which is dependent on both the confining pressure and the rate of confinement increment. None of the existing D-P type models possesses all three features, so they cannot be expected to lead to accurate predictions for both actively-confined and passively-confined (e.g. FRP-confined) concrete.