Abstract: The hysteretic curves of RC piers simulated using fiber beam models exhibit abrupt stiffness changes during the reverse loading phase and insufficient pinching behavior under large displacements. This study conducts a parametric analysis of the mechanisms underlying these discrepancies in hysteretic responses. It is demonstrated that the constant initial strain for inter-crack force transfer adopted by the SITC concrete constitutive model in OpenSees can only eliminate stiffness abruptness within a limited range of loading amplitudes. Moreover, the force-transfer path directed toward the unloading point prevents the concrete from returning to a compressive strain state. Based on the influence of constitutive path parameters on hysteretic behavior, the initial inter-crack force-transfer strain is optimized as the maximum tensile strain, and the reloading path is set to target 1/4 of the unloading stress. This approach effectively eliminates the stiffness abruptness in hysteretic curves across different loading amplitudes. Furthermore, by introducing a softening coefficient and a softening stress correction factor—both correlated with the maximum tensile strain—into the Steel02 reinforcement constitutive model, the hysteretic pinching behavior of piers under large displacements is enhanced. Validation against multiple test piers demonstrates that the proposed modified concrete and steel constitutive models significantly improve the simulation of the full-range hysteretic behavior of reinforced concrete piers.