Vibration test from the perspective of a test engineer: Problems that a wide range of vibrations can cause are often underestimated. Most people probably consider structural damage the root of the main problem, but the damage to components and subassemblies is small. It may not be visible, but it can have dramatic consequences.
This effect can be long-term or temporary functional. Or it can cause weaknesses that don’t immediately affect the product, but later stress can prevent you from completing your work.
Vibration can also cause unwanted noise or resonance products that make the product unusable. During development, these issues can often be fixed with minor vibration fixture design changes.
Know Before testing
Before submitting your product to an accredited laboratory, there are a few things to consider to avoid costly delays. Some of the common problems faced by testing labs are working on vibration test projects:
Inappropriate fixture
- Too heavy
- Too weak/flexible
- Difficult to use (attached files cannot be accessed)
What is your goal?
- Need to demonstrate that the product works during vibration?
- Do you need to demonstrate that the product works after vibration?
Is it a lifetime fatigue test?
- Is it a resonance search test that finds weaknesses?
- Is it a resonant search test to assess whether the product is ergonomically usable or comfortable?
Identify product weaknesses and save time and money
Defects and issues identified early in the product development process are always quick to fix or improve.
Almost all types of products are exposed to some vibration or impact at some stage of their life, whether designed or just in transit. With the right vibration fixture design, testing becomes an excellent tool for finding these weaknesses, whether they affect structure, function, performance, or even product comfort.
Vibration test from the designer/manufacturer’s point of view
One of the reasons why vibration testing is essential for designers is to help identify mechanical failure modes that may have been overlooked at the level, duration, orientation.
A Resonant Peak, for example, a search can help you understand the mechanical vibration frequencies that can be problematic for your application and their sensitivities. Motors or fans in the device should be chosen not to create forced functions at those frequencies. If the design has resonant solid peaks, the designer may change the structural design.
It helps test specific problem areas of the design in a more targeted way than retention testing. The parts of the DUT that are most vulnerable to vibration are tested at problematic frequencies.
The vibration test imposes high acceleration on the DUT while varying the accelerated lifetime temperature. This is a great way to age many mechanical parts artificially.
Impact testing
It can help if you need to simulate an impact or if you need to reveal the failure mode that is most exposed by applying times of intensive force. Run it with an accelerometer before the sign sweep to see what you can expect from the sweep.
Finally, vibration testing can be the key to certain types of sensor designs, especially sensors for vehicles and aircraft, to verify the equipment meets the requirements of applicable defence, aerospace, transportation, and other standards to prevent the sensor from reading erroneous data before it’s too late. It also helps identify performance issues and failures.
