Vibration tests (random and sine wave)
Vibrations will always occur during the transport of a (packaged) product. They can occur due to the surroundings (equipment on board of a plane, ship, or train, by wind or alike) or by the device itself, such as the vibration of engines. The actual level of vibration may be low at times, but because of oscillations as a result of resonance inside the device, the level of vibration may increase significantly. The oscillation may increase to ten or twenty times the original level of vibration. The packaged product or device can be vibrated using multiple frequencies, possibly conditioned for temperature or humidity, to check for compliance with the issued requirements (such as ASTM, ISTA, ISO, IEC MIL STD) or standards of classification companies (such as Lloyds, DNV, GL and such).
There are many types of vibration tests: sinus, random, sinus-on-random and more. Vibration levels and corresponding frequencies differ for each requirement.
A sinus sweep test is a sinus test using a specific frequency range, with a given amplitude and speed. Think about playing all the notes on a piano from left (low tones = low frequency) to right (high tones = high frequency). This sweep test is used to determine the resonance frequencies of a product and/or its packaging. Following the sweep test, the product will be submitted to a long-term test (dwell test) using these frequencies. In practice, resonance leads to damage, as it will cause scuffing damage and material fatigue.
A sinus dwell test tests using a fixed frequency and amplitude. It is used for testing the packaging of, including others, hazardous goods (DOT-test). It is also a typical test for products used in the maritime sector. In the IEC 60945, a shipping industry test is described for two hours at 30 Hz with 0,7 g, functionally testing the product.
Random vibration tests are commonly used for transportation simulations using ASTM, ISTA, IEC, NEN, IEC, ISO or field measurements. These tests simulate the vibration behavior of a truck, train, aircraft or other vehicles. A broad frequency spectrum is struck, using an alternating, simultaneous level of vibration. Products in trains also need to comply with random vibration tests described in the IEC 61373. Similarly, products attached to vehicles, as described in the SAE J1455 and MIL STD 810, must also comply. These are only a few examples, as random vibration tests can be used for any vibration simulation.
Hydraulic vibration table
Using our two Lansmont hydraulic vibration tables, we are capable of performing several types of vibration tests conforming to a standard. The vibration tables are also capable of playing back a real-time vibration profile, combined with an extreme climate and/or low (negative?) pressure. For example:
- Vibration simulation test for trucks combined with +40 degrees Celsius and 90% humidity.
- Vibration simulation test for aircrafts combined with a low (negative?) pressure of 250 mbar and a temperature of -40 degrees Celsius.
- Testing weight max.: 2.700 kg
- Maximum acceleration: 10 g
- Test direction: vertical
- Dimensions tabletop: 1.500 x 1.500 mm
- Frequency range: 0,1 Hz - 300 Hz
- Displacement: 60 mm (peak-peak)
- Temperature range: -40 to 70 degrees Celcius
- Climate range: 5 to 40 degrees Celsius and 98% humidity
- Negative pressure:
- Vibration profiles: Sinus dwell, Sinus sweep and Random
Electric vibration table
Our two Tira electric vibration tables can generate extreme accelerations up to 112 g continuously, both in vertical as well as in horizontal directions. It is possible to perform a vibration test optu 3.000 Hz. Because an electric vibration table is much more accurate than a hydraulic vibration table, it is possible to apply very specific forms of vibration, such as random-on-sine-on-random, as described in AECTP 400 and MIL STD 810.
- Testing weight max.: 1.300 kg
- Maximum acceleration: 112 g continuously
- Test direction: vertical and horizontal
- Dimensions tabletop: 1.200 x 1.200 mm
- Frequency range: 1 Hz – 3.000 Hz
- Displacement: 60 mm (peak-peak)
- Vibration profiles: Sinus dwell, Sinus sweep, Random, Random-on-Sine, Sine-on-Random en Random-on-Sine-on-Random
Do you have questions about our testing methods? Or are you interested in having a vibration test performed? Please contact us. The Sebert Trillingstechniek team will be happy to be of assistance.