On the Critical Velocity of the Sandwich Cylindrical Shell to Moving Internal Pressure

The critical velocity of the infinite long sandwich shell to moving internal pressure is studied using sandwich shell theory and elastodynamics theory.Firstly the propagation of axisymmetric free harmonic waves in the sandwich shell was studied using sandwich shell theory considering the compressibility of core and the transverse shear deformation of core and face sheets.Secondly on the basis of elastodynamics theory,the displacement components expanded by Legendre polynomials,as well as position-dependent elastic constants and densities were introduced into the equations of motion.The critical velocity is the minimum phase velocity on the desperation relation curve obtained using the two methods.Finally the numerical ex amples and FE simulations were executed.Results show that the tow critical velocities agree well with each other,and two desperation relation curves agree well with each other when wave number k is relatively small;however two limit phase velocities approach the shear wave velocities of the face sheet and the core respectively when k limits to infinite.The two methods are efficient to investigate wave propagation in the sandwich cylindrical shell,when k is relatively small.The critical velocity predicted by FE simulations agrees well with that predicted by theoretical analysis.