Vibration analysis

What is vibration analysis?

Vibration analysis is part of the acoustic analysis family. It is a commonly used method of examining the condition of equipment and machinery. It can detect and differentiate between regular machine use or wear-and-tear to faulty components or even a malfunctioning motor. Conducting vibration analysis tests will help you identify these vibrations and determine their source so that you can correct them before they lead to more severe problems with your machine or equipment.

What are the steps to conduct vibration analysis?

Vibration analysis involves steps that help you determine the source of vibration, frequency, amplitude, and direction. The process for vibration analysis is as follows:

1. Planning and preparation: Before the analysis begins, it's essential to understand what machines will be examined, their specifications, and standard operating conditions. Research the machine and gather as much information as possible about its normal operations, including the type of vibration to expect, common problems, etc. Also, determine the points on the machine where measurements will be taken.
2. Setting up equipment: Vibration analysis usually requires specialized equipment such as accelerometers, vibration analyzers, or data collectors. Ensure these are correctly calibrated and set up to measure the specific types of vibration you're interested in.
3. Data collection: Next, measure the vibration levels at various points on the machine. You'll want to measure the vibration frequency, amplitude, and phase angle. The data collector should be securely mounted on the machine at each measurement point, usually at the bearings or shafts. Operating the machine under normal conditions during data collection is also essential to get accurate readings.
4. Data analysis: After collecting the data, it must be analyzed. This often involves using specialized software to process the data and produce a vibration spectrum, frequency, and amplitude graph. This step is crucial to identify any abnormalities or significant changes in the vibration patterns that may indicate a problem.
5. Interpretation of results: Look for any unusual peaks in the spectrum or changes in the vibration pattern over time. These could indicate problems such as misalignment, imbalance, wear, or other mechanical faults. The interpretation requires an understanding of machinery dynamics and vibration theory. The goal is to translate these patterns into actionable insights about the machine's condition.
6. Reporting and action plan: Once you've interpreted the results, they should be compiled into a report. The report should include an action plan detailing any necessary maintenance or repairs. The report can then be presented to the relevant stakeholders or maintenance team for action.
7. Monitoring and trending: After repairs have been made, observe the machine regularly to see if the repairs were successful and to catch any new problems as early as possible. This is where predictive maintenance programs come into play.

What are the vibration analysis parameters?

The most common parameters for vibrational analysis are:

• Frequency: The number of complete cycles in a given period.
• Amplitude: The maximum displacement from the zero position (typically measured in mm).
• Duration: The time required for one complete cycle to occur (typically measured in seconds).
• Location: The location where vibration has been measured is essential because different equipment or processes may have various sensitivities to vibrations at different locations within an assembly or machine.
• Direction: The direction of vibration can be important when identifying its cause because some sources will produce more directional vibrations than others. For example, some sources may produce more axial vibrations while others produce more radial ones; this distinction can help determine whether a particular source is causing problems for your system.

What is an example of vibration analysis?

In our example of vibrational analysis, let's consider an example of a pump in an industrial setting. We use a vibration analyzer and accelerometer for our measurements of the pump. The vibration analyzer records the vibration levels over a set period. The data includes the vibration frequency, amplitude, and phase angle.

The collected data is downloaded into the vibration analysis software. In our example, we discover a high amplitude at a frequency that matches the pump's rotational speed. This could indicate an imbalance problem. You then compile a report with our findings, highlighting the irregular vibrations and their likely causes. In this case, we recommend checking for an imbalance problem and possibly misalignment. The report is sent to the maintenance team, who can then take the necessary actions to repair the problem.

After the maintenance team rectifies the problems, the pump's vibrations are measured regularly to ensure that the imbalance and misalignment issues have been resolved and to catch any new problems early. The vibration analysis thus becomes part of the routine predictive maintenance of the pump, helping to prevent unexpected failures and downtime.

What are the benefits of conducting vibrational analysis?

Vibration analysis is a technique that can be used to identify problems with your products or machinery. It can also help you determine the root cause of those problems, allowing you to make the necessary improvements to achieve better product quality and reliability. In addition, vibration analysis can improve product performance and speed by reducing maintenance costs as well as improving safety.

Discover more benefits of acoustic analysis for maintenance teams