Exploring Frequency Dynamics Techniques: Vibrational Analysis and Predictive Maintenance

Simply because your machines can’t verbally tell you about an impending breakdown or failure doesn’t mean they don’t have anything to say.

Your equipment, structures, and machinery can tell you a lot about their health and condition; you just can’t hear them. Vibrational analysis tools give your assets a voice and lend you an ear to their operating status.

As potentially one of the most popular predictive maintenance tools, vibrational analysis is a vast topic, but we’ll give you the general vibe. 

Keep reading to learn about the key aspects of vibrational analysis and how it may astronomically advance your maintenance operations. 

What Is Vibrational Analysis? 

Vibration analysis (VA) is a process in which vibrations are used to detect levels and vibration patterns within a component, machinery, or structure and identify potential failure points. 

The diagnostic procedure involves analyzing the frequencies, modes, amplitudes, and other characteristics of vibrational frequencies to understand a system's behavior and performance. 

Essentially, VA attempts to predict potential failures and breakdowns in an effort to intercept them before they happen. 

What Is the Principle of Vibration Analysis?

As previously mentioned, vibrational analysis is an extensive science with many components. 

Vibration Characteristics

To provide basic insight into the principles of VA, we will address the primary characteristics of vibrations considered in vibrational analysis, which include:

• Amplitude: The magnitude of the vibration, generally measured in units like displacement (mils or micrometers), velocity (inches or millimeters per second), or acceleration (G’s), which tracks how much an object is vibrating
• Frequency: The measurement for the number of oscillations per unit of time, typically expressed in Hertz (Hz), which tracks how many times an object vibrates in a given period of time
• Phase: The relative timing of the vibration waveform, usually measured in degrees, tracks how the object is vibrating

Vibration Parameters

The three main parameters are used to measure and analyze vibration patterns in comparison to the typical vibrational characteristics of a machine. These parameters are:

• Acceleration: A change in vibration velocity concerning time, a key indicator of force
• Displacement: The distance an object moves from its original position due to vibration
• Velocity: The speed at which an object moves during oscillations, which measures energy dissipation and machine fatigue

Vibration Type

Two major types of vibrations are also used to track readings, which are:

1. Forced vibration: A kind of vibration that occurs when a machine is subjected to periodic, rhythmic force
2. Natural vibration: Aka resonance, this type of vibration tracks the rate at which an object vibrates without being disturbed by an external or damping force

Why Is Vibrational Analysis Important?

Vibration analysis’ ability to predict potential failures makes it a valuable tool for: 

• Planning proactive maintenance 
• Boosting asset performance 
• Preventing unscheduled downtime 

VA tools are highly effective at monitoring machine health, making them one of the main tools in the predictive and preventive maintenance toolbox. 

VA’s condition monitoring abilities help avoid unnecessary overhead and operational losses by:

• Reducing unplanned downtime and scheduling work that fits an organization’s plans.
• Eliminating wasted production costs while unplanned repairs are conducted.
• Delivering products on time with reliable equipment.
• Saving money by boosting product quality through equipment operating at designed performance levels.

According to the Department of Energy, predictive maintenance, coupled with powerful, prevenient tools like VA, may save 8% to 12% in costs over preventive maintenance and 40% over reactive maintenance. 

These potential savings fundamentally negate VA's implementation costs. Yielding a tenfold return on investment (ROI), experts suggest that predictive maintenance strategies like VA may save up to 30% to 40% in costs related to loss and waste. 

How Does Vibrational Analysis Work?

All machines emit a vibrational signature. 

Vibrational analysis tools pick up these vibrational signatures and compare them to measurements associated with known problems and past equipment history.

Most VA tools operate similarly. The difference is the process used to collect the data. 

Data can be collected by:

1. Placing a strong magnet or other connection with a vibration sensor on an established asset location each time a measurement is made.
2. Installing a vibration sensor at a fixed location. The sensor can be connected to a data collector via a wire or through a wireless (IoT) connection.

Having a device that predicts your maintenance needs is revolutionary, but what if you had software that would autonomously generate work orders whenever VA parameters were off? 

UpKeep is a CMMS software with powerful integration abilities. 

By integrating our CMMS with various vibrational analysis tools and software, you can add another layer of predictivity to your predictive maintenance operations. Also, recorded data from predictive maintenance sensors like SensrTrx or Ubidot will give you even more insight into maintenance trends and machine conditions. 

2 Types of Vibrational Analysis Sensors 

VA tools have grown from large, bulky machines to lightweight handheld devices and continuous monitoring instruments. Continuous monitoring instruments have even joined the Internet of Things (IoT) galaxy, which means VA software allows users to view data remotely. 

#1: Portable Devices

A strong magnet or wired connection is frequently used for portable collection devices. 

It allows the person collecting the data to measure many points with one machine and sensor. The portable device is a lower-cost solution that has the added benefit of a technician making visual observations of an asset’s condition during collection.

It also allows technicians to use the device on multiple machines and supplement preventive maintenance routines with regular testing. 

#2: Fixed Devices

Fixed devices have two significant uses:

1. VA sensors can be installed where it may be difficult or dangerous for a human to routinely reach the measurement points.
2. Fixed vibration sensors allow a continuous stream of data to provide immediate alerts and quick responses to critical equipment.

For example, fixed devices are frequently found on high-speed equipment like compressors or turbines. If a potential failure is not detected quickly, this equipment can rapidly damage itself or the humans around it. 

Fixed devices help avoid catastrophic failures using vibrational analysis without endangering technicians in the process. 

What Can Be Detected Through Vibrational Analysis?

Vibrational readings can detect a multitude of potential fail points on a piece of equipment, including:

• Imbalance
• Bent shafts
• Structural deficiencies
• Misalignment
• Poor lubrication
• Electrical motor faults
• And more

These potential breakdown and damage causes may lead to significant costs in repairs and downtime if not detected early with VA tools and software. 

4 Vibrational Measurement Techniques: What Steps Are Involved in Vibrational Analysis?

Implementing vibration analysis is only the first step in actually using and benefiting from this technique. The complete processes of vibration measurement techniques are described as follows:

Calculate the Visible Spectrum 

For most systems, you can measure various points on their vibration spectrum. 

It works on the principle that a vibrational signature may be divided into a series of sine and cosine waves, each with separate amplitudes, frequencies, and phases. 

Generally, an algorithm may isolate data from time into individual components by conveying it to the recorded sine and cosine waveforms. 

Using this data, you can produce a model that illustrates expected vibration behavior.

Establish a Baseline

Establishing baseline data from the information you gathered by calculating the visible spectrum is essential to fully utilizing vibration data in your predictive maintenance program. 

There are normal levels of vibration and acceptable variations that do not indicate failure. Baseline data will set parameters for acceptable performance to make abnormalities clear.

Documenting changes to baselines may also be a significant indicator of recurrent maintenance problems. This means that recording vibration parameters within work orders and maintenance history might provide crucial insights to quickly remedying common issues. 

UpKeep’s CMMS has extensive documenting capabilities. By consolidating vital information regarding your assets in the same place you generate and submit work orders, you can track trends in VA readings and leave notes for your technicians within work orders. 

Maintenance workers will also have access to maintenance history, which may allow them to use readings from previous work orders to swiftly implement solutions and reduce downtime. 

Generate Signal Models

Vibration data must be translated from the format in which it is collected (typically frequency, amplitude, etc.) and digitally reconstructed into a model that can be analyzed. The result is normally a waveform diagram measuring oscillation amplitude over time.

UpKeep’s customizable dashboard allows you to view analytic insights in easily understandable ways. Our CMMS makes it easy to create legible graphs and charts, so even your least technical administrator or manager can remain up to date with current readings. 

Analyze Your Data

This process begins by looking at the harmonics of your vibration data. At this stage, you should notice repeating synchronous peaks or high points in your vibration data. 

The synchronous peaks correlate the frequency peak with the system's physical characteristics, typically indicating a motor rotation or pumping cycle. Spikes in frequencies are entirely normal, but unexpected or unusually high peaks are points to watch out for.

How To Use Vibrational Analysis for Predictive Maintenance

Data collection has to follow a specific pattern to be effective. 

The system measures known failure vibration frequencies and compares data taken at one time with another. Increasing vibration or its impact (how hard it vibrates) identifies a potential issue, which is why measuring at the same time is critical.

VA data systems usually recognize a machine's rotations per minute (RPM). So, it is not critical that a motor that was operating at 1,100 RPM during one collection is now operating at 1,600 RPM. It is only important that the data is collected within the equipment's average operating speed.

The data collection process is usually called a route when using a portable device.

A route establishes:

• The equipment to be measured
• The location of the equipment where the measurement is needed
• The types of tests required at each location

The data collected during the route is loaded into the VA database. The VA software helps to identify irregularities in previous data or deviations from a set parameter. 

The VA technician can take additional measurements and report the findings on a follow-up work order in the computerized maintenance management system (CMMS). If the technician is confident of the necessary next steps, the specific component requiring replacement or service can be included in the follow-up work.

Example of Vibrational Analysis for Predictive Maintenance

Vibration analysis on rotating equipment is more accurate when performed with a 3-axis control test, which is a vibrational test run along three long axes using identical or individualized test profiles.

It provides a more realistic response because a device's faulty vibrations may pass under a single, sequential vibration analysis, but be detected under a multi-axis test. Essentially, a 3-axis test ensures that you are covering x, y, and z when performing vibrational analyses. 

For example, engineers at Inter Pipeline Ltd. of Alberta, Canada, were able to find the root cause of broken weldments by using the power of VA when comparing their readings along a pump's three axes. 

VA has multiple uses beyond traditional applications. It is often used to determine fan balances, drive belt conditions, and even pump cavitation.

Advantages and Disadvantages of Vibrational Analysis

Pros

Vibration analysis is one of the most versatile tools in predictive maintenance programs. Some of the benefits of using vibration analysis to help you with data collection are:

• VA has a long history and a proven track record for reliability.
• The potential for failure can be readily identified.
• Continuous collection allows you to monitor equipment status at all times.
• Anyone can collect data.
• A portable collection route can be rapidly established.
• There are multiple uses of VA beyond the most prevalent bearing failure search.

Cons

There are many strong use cases for and benefits of using vibration analysis as a data collection method. 

Before getting started right away, it’s important to take into consideration any drawbacks that vibration analysis might bring, including:

• A VA system requires an initial setup, which entails additional costs. The effort can be reduced with a solid CMMS like UpKeep.
• A VA “champion” must be certified, trained, and allowed to operate.
• “Failed bearings” are not easily recognized by many. The old test of spinning it in your hand cannot duplicate the pressures and speeds when most bearing failures are detected.

How UpKeep’s CMMS Integrates With Vibrational Analysis Tools for Successful Predictive Maintenance Practices

Predictive maintenance strategies are essential to keeping downtime, loss-related costs, and breakdown frequency low. 

Your assets can’t effectively communicate potential issues to you without a bit of help — even your vibrational analysis reading could get lost in translation without the proper predictive maintenance tool. 

UpKeep allows you to keep up with the health and condition of your equipment and the efficacy of your maintenance schedules with a comprehensive CMMS solution. 

We also have a growing ecosystem of integrations that are continuously added as vibrational analysis tools and IoT sensors advance with CMMS capabilities. 

Are you interested in integrating your current asset monitoring tools with UpKeep? Inquire about our available integrations or see if we can integrate your VA tool and software with our CMMS.

Let our powerful maintenance management software speak for itself. Schedule a free demo today.