Vibration Response of Products

vibration response

Tacoma Narrows Bridge collapse, caused by improperly designed structure

Vibration of a mechanical system can be descried as an oscillatory motion about an equilibrium point. Certain vibrations of mechanical systems can be considered desirable, such as in musical instruments like a tuning fork or guitar.

However, often times vibrations of mechanical systems are undesirable, producing wasted energy, unwanted noise and catastrophic failures. Therefore it is critical during the product design phase that engineers are able to accurately characterize the vibration response of the system in order to ensure a safe and reliable product for their customers. We accomplish this through comprehensive vibration testing services.

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DES Performs Testing for Orion Rocket Program

delta4hvy-bkgrdDelserro Engineering Solutions (DES) was proud to be a part of the recent Orion rocket that launched on December 5th 2014. DES was contracted by a local manufacturer to help qualify their product designs for use on Lockheed Martin’s Orion rocket. DES’s role was to perform specialized shock testing on their products.

Some of the shock levels were over 3200 G’s to simulate the rugged launch environment. Both the local manufacturer and Lockheed Martin Corporation were pleased with the testing. Their products successfully passed the shock tests at DES. They acknowledged DES’s role and informed DES that their products operated successfully during the launch!

What sets DES apart from other labs is our in depth experience and technical capability to understand and reproduce the most complicated vibration and shock profiles. DES continues to perform the most complex vibration and shock tests on products that are used in outer space, rockets, missiles, automotive & truck environments, military environments, hospitals, etc.

Temperature Cycling Testing: Coffin-Manson Equation

Temperature cycling testing is another method of accelerated life testing for products that are exposed to temperature variations during use in normal operation. The temperature variations can be a result of self heating for products that are repeatedly turned on and off, or can be the result of cyclic environmental changes — such as temperature variations from day to night — or other causes.

thermal cyclingThese repeated temperature changes can result in thermal fatigue and lead to eventual failure after many thermal cycles. Accelerated life testing can be performed by cycling the product to high and low temperatures that exceed its normal use temperatures.

It should be noted that temperature cycling may also be referred to as thermal cycling or thermal shock testing.  However, some test standards, such as MIL-STD-883, make the distinction between temperature cycling being performed as air to air testing and thermal shock being performed with the samples transferred between liquids. This article deals with testing performed using an air to air thermal cycle chamber.

Typical temperature cycling equipment consists of at least one hot chamber and one cold chamber. The test samples are automatically transferred between the two chambers by an elevator-type mechanism. It is also possible to perform temperature cycling in a single compartment chamber where the temperature is ramped between hot and cold. This generally produces a slower rate of temperature change compared to the two chamber method.

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Sinusoidal Vibration Basics

F22 Raptor Plane - Sinusoidal Vibration BasicsThe brilliant scholars at CalPolyTech have diligently evaluated and assessed the Fundamentals of Vibration Measurement and Analysis in a way that even lay persons can get a grip on the fundamentality of measuring vibrations for differing purposes and projects.  This reference for comprehending the physics behind the elemental vibration measurement and analysis will prove invaluable to the product managerial departments, industrial engineers, developers, and all with decision making power in the testing or product development field.

See Sinusoidal and Random Vibration Testing Primer for a more technical explanation of sinusoidal vibration testing.

See Sinusoidal Vibration Testing to learn more about the different types of sinusoidal vibration testing.

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DES Adds New Unholtz-Dickie Vibration Test System

Vibration Testing Bed

Our new Unholtz-Dickie vibration and shock testing platform.

To keep up with increasing vibration and shock testing demand, DES added a brand new Unholtz-Dickie Electro Dynamic (ED) Shaker Test System. The shaker is a model SAI30F-S452/ST system with slip table to perform vibration and shock testing along 3 axes. This gives DES additional vibration and shock testing capability and also will help us turn your projects around faster. Continue Reading DES Adds New Unholtz-Dickie Vibration Test System

Case Study: Combined Temperature & Vibration Testing of Automotive Mass Air Flow Sensors

Mass Air Flow Sensors (MAFS) are used to measure the mass flowrate of air entering engines in newer model cars. The mass air flow information is transmitted to the engine control unit (ECU) to balance and deliver the correct amount of fuel mass to the engine.  These sensors operate in a very harsh environment, a car engine compartment! Testing their reliability and proving their durability is a very difficult task.

Mass Air Flow Sensors (MAFS) Combined Temperature Vibration Testing
Mass Air Flow Sensors (MAFS) Combined Temperature Vibration Testing

DES was awarded multiple contracts to perform combined temperature and vibration reliability testing of Mass Air Flow Sensors from various automotive part manufacturers and from a major auto parts supplier. Continue Reading Case Study: Combined Temperature & Vibration Testing of Automotive Mass Air Flow Sensors

Vibration Testing: A Questionnaire for Clients

Figure 3.  Vibration Testing using a Cube Fixture

Vibration testing can be a complicated process. We have created this questionnaire to help make communication between the vibration test lab and customer more efficient. The questionnaire allows us to capture all the pertinent facts about your test requirements. Providing the information below will help us provide an accurate quotation and to perform a successful vibration test. We can help you with answering the questions if needed. Many engineers, not familiar with vibration and shock testing, a subject not taught by universities, may wish to further their education.  May we respectfully suggest that you visit http://equipment-reliability.com/training-calendar/vibration-and-shock-testing/  for vibration and shock training courses. Continue Reading Vibration Testing: A Questionnaire for Clients

Random Vibration Testing

Random Vibration Testing is one of the more common types of vibration testing services performed by vibration test labs. A primer containing a technical explanation on random vibration testing can be found in our blog article Sinusoidal and Random Vibration Testing Primer.

Real world vibrations are usually of the random type. Vibrations from automobiles, aircraft, rockets are all random. A random vibration test can be correlated to a service life if the field vibrations are known. Since random vibration contains all frequencies simultaneously, all product resonances will be excited together which could be worse than exciting them individually as in sine testing. Sometimes random vibrations are mixed with sine vibrations in Sine-on-Random Vibration Testing. Also, a low level of broad band random vibration can be mixed with additional high levels of narrow band random vibrations in Random-on-Random Vibration Testing.

Some common test standards that have specifications for Random Vibration Testing are: Continue Reading Random Vibration Testing

DES Increases Combined Temperature & Vibration Testing Capabilities

Vibration Testing - Delserro Engineering SolutionsVibration Testing - Delserro Engineering SolutionsDES added another larger AGREE Chamber to perform Combined Temperature and Vibration Testing. This gives DES additional capability to perform combined environmental testing on larger products. DES has performed Combined Temperature and Vibration Testing on car engine sensors, helicopter sensors and outdoor heavy industrial products. Some of the test specifications include MIL-STD-810 and General Motors GMW 3172.

The Equipment Capabilities Are:

  • Combined shock or sinusoidal, random, mixed mode vibration and temperature
  • Temperature range from -80°C to +180°C (-112°F to +356°F)
  • Temperature rate of change up to 20°C/minute
  • 9 cubic feet interior work space, cvo

To learn more about our combined temperature and vibration testing services, visit our website, and be sure to contact us if you would like to find out how our services can work for your products.

Sinusoidal Vibration Testing

Sinusoidal or Sine Vibration Testing is one of the more common types of vibration testing services performed by vibration test labs. See Sinusoidal Vibration Basics to learn more about vibration fundamentals. A primer containing a more technical explanation on sinusoidal vibration testing can be found in our blog article Sinusoidal and Random Vibration Testing Primer. The types of Sinusoidal Vibration Testing are Sine Sweep Vibration Testing, Sine Dwell Vibration Testing, and Sine-on-Random Vibration Testing.

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