Vibration coupling analysis of tube sheet and tube bundle

The vibration coupling analysis of the tube sheet and tube bundle requires attention to the transmission characteristics of the fluid excitation source. When the shell-side fluid flows transversely, periodic vortex shedding (Karman vortex street) or turbulent pressure pulsations are transmitted to the tube bundle through the tube sheet support structure, creating a risk of resonance. This risk is particularly significant when the excitation frequency approaches the natural frequency of the tube bundle, leading to a substantial increase in amplitude.

The tube sheet, acting as a fixed interface, has its structural stiffness and support method directly influencing the coupling effect. Using high-rigidity materials (such as titanium alloy) or adding anti-vibration support plates can increase the natural frequency of the tube sheet, disrupting the matching conditions between fluid excitation and structural resonance, thereby suppressing vibration transmission.

The coupling analysis requires a comprehensive consideration of fluid-structure interaction. By optimizing the tube sheet-tube bundle connection method (such as elastic expansion joint) and controlling the flow velocity, the vibration energy input caused by fluid elastic instability can be reduced, preventing tube sheet seal failure or tube bundle fatigue cracking due to long-term alternating stress.