Due to the complexity of the damping mechanism of composite cylindrical shell

there is no practical and effective method to identify such structural damping.A modal damping test method based on sliding-envelop method was proposed.First

damping test principle and overall plan of sliding-envelop method for modal damping of composite cylindrical shell were clarified in details.Then

its test procedures in the actual test of modal damping of composite cylindrical shell were summarized.At last

a composite cylindrical shell coated with constrained layer damping materials was used as a study object

and its modal damping were well identified and the relation between external excitation level and modal damping was discussed.Test results showed that the maximum variance obtained by the proposed method corresponding to the first five orders damping result was less than 0.02%

and the damping results had good repeatability

thus ensuring high testing precision.