In order to study the law of dynamic parameter change of power cable sheath in the case of structural damage

a mathematical model for vibration damage of the power cable sheath structure was established and solved. Frequency response analyses were performed on the intact sheath structure of the power cable and the damaged sheath structure of the power cable

and a structural vibration test was conducted on the power cable sheath using the hammer method. According to the vibration test data

the structural damage of the power cable sheath was discriminated. The research findings reflect the damage characteristics of the power cable sheath structure. The damage of the power cable sheath structure leads to the dynamic parameter change. The peak frequency response function（FRF） curvatures range between 0.082 and 0.55 in the case of the intact power cable sheath and power cable sheath depressed by 0.8 mm. The FRF curvatures can be used to locate the damage to the power cable sheath.