Mixed Mode: Sine on Random Vibration Testing, RoR, SoRoR
Mixed Mode Vibration Testing is less common than Sinusoidal and Random Vibration Testing. However, it does have a special purpose for simulating specialized helicopter vibration or vibration from tracked vehicles such as tanks. The three mixed modes of vibration testing are: Sine-on-Random (SoR) Random-on-Random (RoR) Sine-on-Random-on-Random (SoRoR) Some common test standards that have specifications for Mixed Mode Vibration Testing are: MIL-STD-810 Department of Defense Test Method Standard for Environmental Engineering Considerations and Laboratory Tests RTCA DO-160 Environmental Conditions and Test Procedures for Airborne Equipment
What is a Vibration Resonance?
A vibration resonance occurs when equipment or a product is exposed to an external forced vibration occurring at one or more of its natural frequencies. The resulting product response vibration is amplified and can be huge! Vibration resonances can cause severe damage to products and significantly shorten their life. Examples of vibration resonances can be seen below and in our video page. A natural frequency is the frequency at which a system will oscillate after an external force is applied and then removed. All objects have a natural frequency at which they vibrate. Most products have many natural frequencies.
Vibration Response of Products
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.
DES Performs Testing for Orion Rocket Program
Delserro 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…
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. These 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….
Sinusoidal Vibration Basics
The 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…
DES Adds New Unholtz-Dickie Vibration Test System
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.
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 DES was awarded multiple contracts to perform combined temperature and vibration reliability testing of Mass Air Flow Sensors from various automotive…
Vibration Testing: A Questionnaire for Clients
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…
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…