%0 Journal Article %T Achievements of Truss Models for Reinforced Concrete Structures %A P. G. Papadopoulos %A H. Xenidis %A P. Lazaridis %A A. Diamantopoulos %A P. Lambrou %A Y. Arethas %J Open Journal of Civil Engineering %P 125-131 %@ 2164-3172 %D 2012 %I Scientific Research Publishing %R 10.4236/ojce.2012.23018 %X Achievements are presented for truss models of RC structures developed in previous years: 1. Two constitutive models, biaxial and triaxial, are based on regular trusses, with bars obeying nonlinear uniaxial ¦Ò-¦Å laws of material under simulation; both models have been compared with test results and show a dependence of Poisson ratio on curvature of ¦Ò-¦Å law. 2. A truss finite element has been used in the nonlinear static and dynamic analysis of plane RC frames; it has been compared with test results and describes, in a simple way, the formation of plastic hinges. 3. Thanks to the very simple geometry of a truss, the equilibrium equations can be easily written and the stiffness matrix can be easily updated, both with respect to the deformed truss, within each step of a static incremental loading or within each time step of a dynamic analysis, so that to take into account geometric nonlinearities. So the confinement of a RC column is interpreted as a structural stability effect of concrete. And a significant role of the transverse reinforcement is revealed, that of preventing, by its close spacing and sufficient amount, the buckling of inner longitudinal concrete struts, which would lead to a global instability of the RC column. 4. The proposed truss model is statically indeterminate, so it exhibits some features, which are not met by the ¡°strut-and-tie¡± model. %K Reinforced Concrete Structure %K Truss Model %K Constitutive Law %K Material and Geometric Nonlinearities %K Concrete Cracking %K Reinforcement Yield %K Concrete Ultimate Compressive Strength %K Plastic Hinge %K RC Column Confinement %K Buckling of Inner Concrete Struts %K Global Instability %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=22985