MIL-STD-810 Vibration Testing Overview [Method 514.8]
by Brett Daniel, on May 15, 2020 10:35:07 AM
Graphic: A Trenton Systems 2U rugged blade server in motion. MIL-STD-810 vibration testing may be worth looking into if your rugged computer is expected to experience general vibration or transport vibration during its life cycle.
We know that rugged servers and workstations can experience quite a bit of vibration during transport and operation, and unfortunately, suffer damage or impairment as a result.
Test Method 514.8 of MIL-STD-810, which covers both general and transport vibration, can help with that.
What is MIL-STD-810 vibration testing?
According to MIL-STD-810H, the purpose of vibration testing, also known as Test Method 514.8, is to assess the functionality and durability of a system after it has been exposed to intense shaking and juddering.
The goal, of course, is for the system to pass certain MIL-STD-810 vibrational procedures to ensure continued operation in the event of an exposure. Testing is typically performed using vibration testing equipment, such as a vibration exciter or vibration testing table.
Exposure to a harsh vibrational environment can severely damage or altogether destroy uncertified rugged computers and their components.
How does MIL-STD-810 vibration testing protect your rugged server?
Certifying your server to the procedures in Method 514.8 ensures protection in the field by assessing how resistant a system is to varying levels of vibration in application-specific environments.
This translates directly to dollars saved on repairs or replacements resulting from extensive physical damage and a short life cycle.
MIL-STD-810H provides the following examples of problems that can result from general or transport vibration:
- Chafed wiring
- Loose fasteners, components
- Intermittent electrical contacts
- Electrical shorts
- Deformed seals
- Failed components
- Optical or mechanical misalignment
- Cracked or broken structures
- Migration of particles and failed components
- Particles and failed components lodged in circuitry or mechanisms
- Excessive electrical noise
- Fretting corrosion in bearings
As you can see, there’s no shortage of damage that can occur when a system endures an exposure.
What are the MIL-STD-810 vibration testing procedures?
There are four procedures in Method 514.8, each of which are unique to the eventual use and application of a particular system:
- Procedure I – general vibration – for systems that are tied down or secured during transportation or that are intended to be deployed on a vehicle at some point during their life cycle.
- This test covers both transportation and operational conditions and involves securing a system to vibration testing equipment for assessment
- Procedure II – loose cargo transportation –for systems that will be transported in trucks or trailers and that won't be secured or tied down
- This test involves placing the unsecured system onto vibration testing equipment for assessment. Fencing is often installed around the system to prevent it from falling off the vibration table during testing.
- Procedure III – large assembly transportation – for big collections of systems forming a higher proportion of vehicle mass that are installed on or being transported by wheeled or tracked vehicles
- This test involves placing the system onto or inside of the type of vehicle that will be used for transportation. The vehicle is driven over surfaces that will be encountered during the system’s life cycle, resulting in an application-specific simulation demonstrative of real-world vibrations
- Procedure IV – assembled aircraft store captive carriage and free flight – for systems fixed or mounted on aircraft
- This test involves the use of vibration exciters that drive the test item directly or through a fixture.
MIL-STD-810H also provides a vibration environment categories table to help test engineers determine which procedures to perform based on the product’s life cycle phase and application.
Environment Categories for Vibration Testing
Screenshot: Vibration environment categories table courtesy of MIL-STD-810H
Scenario: The MIL-STD-810 servers are alright
Judders and shudders and jouncing, oh my!
A cargo truck is delivering four 2U rugged servers to a military installation, where they’ll provide much-needed data and file storage to the many soldiers stationed there.
The truck is traversing through the desert across rocky, bumpy, rugged terrain. It’s a lot coarser than the driver expected, and unfortunately, he's unaware that the servers, along with the other cargo in the trailer, have become unsecured as a result.
Shaking violently in place, the servers are now enduring a constant torrent of vibrations, forceful enough to detach fasteners and components and even crack the chassis.
And when the truck driver travels over a particularly steep bump or a cavernous dip in the path, the servers either collide with the other cargo or crash against the side of the trailer.
The driver arrives at the installation and realizes what has happened.
He meets with one of the information technology specialists there and expresses his concerns.
“It was a pretty bumpy drive, and the servers, unbeknownst to me, became unsecured about 10 miles from here,” he says. “To be honest, sir, I wouldn’t be surprised if they’re severely damaged or completely toast.”
At the gesture of the IT specialist, the driver opens the door to the trailer, and there the servers lie.
The look on the IT specialist’s face says it all.
Gazing into the military cargo truck’s trailer, his eyes lit up.
“There’s nothing to worry about,” he told the worried driver. “We knew the computers would experience a bit of vibration during transport, so we prepared for that by having them MIL-STD-810-certified.”
“Yep, and from the looks of the other broken items in the trailer, I’d say it’s a good thing we did.”
Collage: A 1U Trenton Systems rugged server being tested on our in-house vibration testing table, used to test the vibrational resilience of our MIL-STD-810 servers and workstations
How does Trenton Systems vibe-test its systems?
At Trenton Systems, we conduct our very own vibration table testing using our in-house shock and vibration testing table, which allows us to certify your system to the shock and vibration standards in MIL-STD-810.
Vibration testing services are typically requested directly by customers or listed as a requirement during the bidding process.
We can perform shock and vibration testing in-house at Trenton Systems up to certain limits and thresholds. Beyond that, we have testing labs we work with locally that can accommodate testing requirements beyond our capabilities. We can also provide customers with our shock and vibration test reports, which demonstrate just how resilient their customized rugged server or workstation is.
-Gary Ziadeh, compliance coordinator at Trenton Systems
Visit our Compliance Page to learn more about testing standards and how we ensure your program or application is equipped with a durable, reliable server that meets your needs.