屈曲约束支撑核心单元的受力形态是影响其低周疲劳特性和滞回特性的重要因素。基于屈曲约束支撑核心单元的受力特点,建立了基本假定,并依据承受轴向荷载和侧向荷载杆件的平衡方程,推导了核心单元与约束单元点接触和线接触状态下的挠曲线方程,揭示了其在持续增大的轴向力作用下点接触、线接触和新波生成交替出现的多波屈曲过程。算例分析表明:该文提出的计算公式与数值分析计算结果相一致,可用以描述核心单元在约束单元内的受力特性。 The force form of buckling restrained core element is an important factor that affects the low cycle fatigue and hysteretic characteristics. The basic assumption is established based on the force characteristics of the core element supported by buckling restraint. According to the balance equation of the axial load and lateral load member, the deflection curve of the core element and the restraining element at the point contact and the line contact is derived , Reveals the multi-wave buckling process of point contact, line contact and new wave alternation under the action of increasing axial force. The case study shows that the calculation formula proposed in this paper is consistent with the numerical analysis and can be used to describe the force characteristics of the core unit in the constrained unit.