This paper evaluates the applicability of several concrete models to simulate the behavior of concrete elements under monotonic and cyclic loadings. Several robust constitutive models based on the combination of plasticity and continuum damage or plasticity and smeared crack approach are selected. The behavior of one concrete element is evaluated under different uniaxial compression, uniaxial tension, biaxial compression, biaxial tension, biaxial compression-tension, and triaxial compression loads. Then, the applicability of the concrete models is investigated for two flexural beams under cyclic loading. Five concrete models available in the versatile finite element-based software LS-DYNA are selected, including Winfrith, CSCM, RHT, KCC, and CDPM. The prepeak, peak, and postpeak behaviors of all selected models are presented, including initial stiffness, peak strength, strain at peak strength, postpeak stiffness, and failure strain.concrete constitutive models, finite element analysis, LS-DYNA, monotonic and cyclic loading
| INTRODUCTION AND BACKGROUNDMost finite element models identify the concrete with its elastoplastic behavior in compression and with a brittle elastic behavior in tension. A large variety of elasticity-and plasticity-based constitutive models have been proposed in recent years for the prediction of the uncracked concrete behavior, including empirical models, linear elastic, nonlinear elastic, plasticity-based models, models based on endochronic theory of inelasticity, fracturing models, and continuum damage mechanics models. [1] Various plasticity models have been developed for a better description of concrete compression strength under multidirectional stress states. The approach of plasticity models can be path-independent deformational theory or incremental theory, in which the total strain or total strain increment can be obtained by summation of elastic and plastic strain or strain increment, respectively. Assuming a linear elastic behavior for concrete can be quite accurate until it reaches to its peak tensile strength. [2] Under the compression loading, the behavior of concrete is highly nonlinear and inelastic. This model predicts the results with high error in cyclic loading. Under multiaxial compression loading, the use of nonlinear elastic models increases accuracy compared to linear elastic models. [3] These nonlinear elastic models can be categorized as secant formulations (hyperelastic models), which are path-independent and applicable to the monotonic or proportional loading, or tangential formulations (hypoelastic models), which better describe the concrete behavior under cyclic and nonproportional loading.For a better representation of concrete behavior in compression, different plasticity-based constitutive models have been developed over the last few decades. [4][5][6][7][8] All plasticity models are composed of three main components: yield criteria, flow rule, and hardening rule. The yield surface of concrete could be achieved by applying some corrections on the failure sur...