How can you choose the right vibration control method?

1 What is vibration control?

Vibration control is the process of designing, installing, or modifying structural elements or devices to alter the dynamic response of a structure to vibration. There are two main types of vibration control methods: passive and active. Passive methods use physical properties or geometries of materials or structures to dissipate or isolate vibration energy. Active methods use sensors, actuators, and controllers to apply counteracting forces or displacements to cancel or minimize vibration. Both methods have their advantages and disadvantages, depending on the vibration source, frequency, amplitude, and structure characteristics.

2 How to identify the vibration source and frequency?

Before choosing a vibration control method, you need to identify the vibration source and frequency. The vibration source can be external or internal, depending on whether it originates from outside or inside the structure. External sources include wind, traffic, earthquakes, and nearby construction activities. Internal sources include machinery, elevators, pumps, fans, and human activities. The vibration frequency is the number of cycles of vibration per second, measured in hertz (Hz). The vibration frequency can be determined by using instruments, such as accelerometers, strain gauges, or microphones, or by using analytical methods, such as finite element analysis or modal analysis.

3 How to select a passive vibration control method?

Passive vibration control methods are usually simpler, cheaper, and more reliable than active methods. However, they are also less flexible and adaptable to changing vibration conditions. Passive methods can be classified into three categories: damping, isolation, and absorption. Damping is the process of converting vibration energy into heat or other forms of energy that are dissipated by the structure or material. Isolation is the process of separating the structure or component from the vibration source or path by using springs, rubber pads, or other elastic elements. Absorption is the process of reducing the vibration amplitude by using mass-spring-damper systems that resonate at the same frequency as the vibration source.

4 How to select an active vibration control method?

Active vibration control methods are usually more complex, expensive, and sophisticated than passive methods. However, they are also more effective and versatile in dealing with variable or unpredictable vibration sources and frequencies. Active methods can be classified into two categories: feedback and feedforward. Feedback is the process of measuring the vibration response of the structure or component and applying a counteracting force or displacement based on a control algorithm. Feedforward is the process of measuring the vibration source or disturbance and applying a counteracting force or displacement based on a predictive model.

5 How to evaluate the effectiveness of a vibration control method?

The effectiveness of a vibration control method depends on several factors, such as the vibration criteria, the performance indicators, the cost-benefit analysis, and the environmental impact. The vibration criteria are the standards or specifications that define the acceptable levels of vibration for a given structure or component. The performance indicators are the metrics or parameters that measure the vibration response or quality, such as acceleration, displacement, strain, stress, noise, or comfort. The cost-benefit analysis is the comparison of the costs and benefits of implementing a vibration control method, such as the initial investment, the maintenance, the energy consumption, the durability, and the savings. The environmental impact is the assessment of the potential effects of a vibration control method on the surrounding environment, such as the emissions, the waste, the noise, or the aesthetics.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?