考虑流体静压时充液圆柱壳的输入能量流特性

Input Vibration Power Flow in Fluid-filled Cylindrical Shells Considering Hydrostatic Pressure

研究了内部流体静压力对充液圆柱壳的受迫振动能量流的影响。静压力作为预应力计入壳体振动方程当中,壳体和流体分别采用Flügge方程和Helmholtz波动方程。分析了耦合系统在周向线分布余弦载荷下的动态响应,用傅立叶变换和反变换实现空间域与波数域之间的相互转换,采用留数定理求取系统的响应并得到耦合系统的输入能量流。结果表明,周向模态数n=0时,静压力对耦合系统的输入能量流影响很小;n较大时,在中低频下静压力使输入能量流曲线沿频率轴右移,由于输入能量流的峰值点处的频率对应于频散曲线中各支传播波的截止频率,对应传播波的截止频率升高,高频时则基本无影响。随着静压力以及周向模态数的增大,输入能量流受到的影响程度也增大。

The effects of internal hydrostatic pressure on input vibration power flow in cylindrical shells filled with fluid were investigated. The hydrostatic pressure was modeled using static pre-stress terms in the shell equations of motion. The structural and fluid equations of motion were taken from Fltigge thin shell theory and Helmhohz wave equation respectively. By using the Fourier transform and its inverse transform and applying residues theorem, the input power flow into the coupled system under a line cir- cumferential cosine harmonic driving force was studied. The results showed that the hydrostatic pressure had practically no effect on input power flow for circumferential mode order n=0. For high circumferential modes, the input power flow curves translated to right along frequency axis when considering hydrostatic pressure at mid and low frequencies. Since the frequencies of the peaks in the input power curve corre- sponded to the cut-on frequencies of the propagating waves in the dispersion curves, the cut-on fre- quencies of the corresponding propagating waves increased. For higher pressure and larger circumferential mode order, the effects input power flow was more significant.