Plasticity model for partially prestressed concrete

Abstract

Recently, the partially prestressed concrete (PPC) has been widely used as an effective construction technique for structures to reduce yielding and damages. However, there is no proper analytical model for PPC frame elements (beam-column members) to perform the finite element analysis. Besides, an extensive review of the literature uncovered little available information about the possibility of identifying damage to PPC members during applied vibration loads such as earthquake excitation. Hence, this paper presents the development of a new 3D analytical model for PPC beam-column element subjected to static and dynamic loads. In addition, a theory of plasticity and yielding surfaces for PPC frame elements are formulated in order to detect damage and determine the location of plastic hinges in the structural components under dynamic load. The developed analytical and plasticity models were codified and implemented in a finite element program in order to perform inelastic static and dynamic analysis for PPC structures. Then, sample PPC beam and frame members were cast and tested experimentally for flexural and incremental loading, respectively, to verify the developed analytical and plasticity model for PPC. The results show a good agreement between the analytical model and numerical analysis and the experimental test results. In addition, a comparison of the seismic response of reinforced concrete (RC) and PPC structures indicated that the stiffness and energy dissipation capacity of the structure with PPC members improved noticeably and the total number of plastic hinge formations in the structural members decreased.