Research on the Vibration Characteristics of a Compounded Periodic Strut Used for Helicopter Cabin Noise Reduction

Table 1

Material characteristics.

Material	Elastic modulus; (GPa)	Density; (kg/m^3)	Poisson’s  ratio	Loss factor	Allowable stress; (MPa)
Nitrile rubber	0.005	1000	0.49	0.3	3
45# steel	210	7860	0.3	∖	355