Abstract In this paper, new models were proposed for calculating the axial strain and the stress-strain curves of actively and passively confined (such as fiber-reinforced polymers confined) concrete columns. A new energy absorption method was introduced to establish a relationship between the energy absorbed by the concrete column and the lateral confinement. Based on energy-balance approach analysis, the characteristics of actively and passively confined concrete columns were thoroughly analyzed, and the transfer factor was presented. For actively confined concrete columns, the peak strain estimation model and the stress-strain relationship of the softening branch were proposed. For passively confined concrete columns, the models of passive strain, the demarcation point and the confined coefficient were proposed. Finally, the constitutive models of two types of confined concrete were established. The proposed models were established by strong theoretical foundation and clear mathematical derivation and could provide accurate prediction results.

中文翻译：

---

主动和被动约束混凝土的分析本构模型

摘要 本文提出了计算主动和被动约束（如纤维增强聚合物约束）混凝土柱的轴向应变和应力应变曲线的新模型。引入了一种新的能量吸收方法来建立混凝土柱吸收的能量与侧向约束之间的关系。基于能量平衡法分析，深入分析了主动约束和被动约束混凝土柱的特性，并给出了传递系数。针对主动约束混凝土柱，提出了峰值应变估计模型和软化支路的应力应变关系。针对被动约束混凝土柱，提出了被动应变模型、分界点模型和约束系数模型。最后，建立了两类约束混凝土的本构模型。所提出的模型具有较强的理论基础和清晰的数学推导能力，能够提供准确的预测结果。