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研究了内、外壳体敷设粘弹性阻尼材料的有限长加肋双层圆柱壳的振动和声辐射性能,采用经典Flugge微分算子描述壳体的运动,运用Helmholtz波动方程和壳体表面的边界条件来求解位于内、外层壳之间的环形流场,并利用傅氏变换, 可以求出声压的表达式,粘弹性阻尼层的运动用三维Navier方程描述,将阻尼沿厚度方向的位移用泰勒展开表示,利用不同的位移和应力的连续性边界条件分别建立了无阻尼以及三种阻尼材料敷设方式的振动方程,并用数值计算讨论了光壳和三种阻尼材料敷设方式对三种壳间连接形的双层壳体振动和声辐射的影响,结果表明敷设阻尼材料能降低壳体的辐射噪声,并且内壳敷设阻尼比外壳敷设阻尼的减振降噪效果好,内外壳均敷设阻尼材料的减振降噪效果最好。
The vibration and sound radiation of a finite length ribbed double cylindrical shell with viscoelastic damping material applied to the inner and outer shells are studied. The classical Flugge differential operator is used to describe the shell motion. The Helmholtz wave equation and the boundary conditions of the shell surface To solve the annular flow field between the inner and outer shells, the expression of the sound pressure can be obtained by Fourier transform. The motion of the viscoelastic damping layer is described by the three-dimensional Navier equation. The damping displacement along the thickness direction is represented by Taylor expanded to show that the vibration equations of undamped and three damping materials are established respectively by using different boundary conditions of displacement and stress. Numerical examples are given to discuss the effect of light shell and three kinds of damping materials on the vibration modes of the three shells The results show that the damping material can reduce the radiation noise of the shell, and the damping effect of the inner shell laying damping is better than that of the outer shell laying damping. The inner shell and the outer shell are all provided with damping materials The best vibration and noise reduction.