提出了基于应变能的索穹顶结构索杆破断敏感性分析方法及其指标，给出了敏感性系数的定义，即索杆破断后振动过程中结构总应变能变化幅值与索杆破断前平衡态结构总应变能的比值． 以此系数作为评价结构对索杆破断敏感性的整体指标，将其应用于Levy 型索穹顶结构索杆破断的敏感性分析，并与其他方法及指标进行了对比． 结果表明:Levy 型索穹顶对环索和中心撑杆的破断最为敏感，其中最外圈环索破断对应的敏感性系数最大，因此应着重提高环索和中心撑杆的安全储备; 文中提出的评价指标对柔性索穹顶结构较为适用，能够从宏观上表征结构对索杆破断的敏感程度．

Proposed are a strain energy-based sensitivity analysis method and the corresponding evaluation index of cable-strut rupture for cable domes.Firstly,a sensitivity coefficient is defined as the ratio of the change amplitude of structural total strain energy in the vibration process after cable-strut rupture to that under the equilibrium before cable-strut rupture.Then,the defined coefficient is used as an overall index to evaluate the sensitivity of cablestrut rupture and is applied to the sensitivity analysis of cable-strut rupture for Levy cable dome.Finally,a comparison is made between the proposed method /index and the existing ones.The results show that Levy cable dome is most sensitive to the rupture of hoop cable and middle strut,and that the corresponding sensitivity coefficient reaches the maximum when the outer hoop cable is ruptured.Thus,the safety margin of hoop cable and middle strut should be both improved.The presented evaluation index is more applicable to flexible cable domes and is effective in representing the sensitive degree of structure to cable-strut rupture macroscopically.