Jim Shaw, EVP of Engineering at Crystal Group, discusses MIL-STD-810 Method 514.6 Testing
Read Video Transcript: Episode 81 – “MIL-STD-810 Test Method 514.6 Vibration”
Hi, Jim Shaw here from Crystal Group. We’re talking today a little bit more about MIL-STD-810. Today we are talking about vibration. Probably one of the more complicated aspects of the testing described in MIL-STD-810. It’s also one of the more interesting ones. MIL-STD-810 Method 514 has four different procedures in it that talk about different modes of vibration that a unit might withstand. And we’re generally interested in procedures 1 and 2 that talks about either shipping or operational vibration.
What are you looking for in this test? This test is looking for wires that might chafe, circuit boards that might crack solder joints or have damage. It’s looking for fatigue failures in metals or materials. It’s looking for breakage and loose parts rattling through the box. It’s essentially supposed to represent the entire lifetime of damage that a unit might actually endure. There’s a lot of different categories in this particular method but in essence its job, its test job is to go out and look for will this thing live its life without damage or problems.
Keeping in mind that were pretty focused on Procedure 1 and Procedure 2 for 514 what we do is we have, there are over 25 categories of different kinds of profiles that you can test to and each category is a book upon itself. You can go down this rabbit hole pretty fast but for the most part we as a company are concerned about categories 4 through 21. Four is cargo, 21 is marine vehicles. Each different category has a different vibration profile in terms of the spectrum, the frequency and the amplitude of energy that the units are subjected to. What you end up doing is establishing the procedure, the timeline and then you start going into the category and trying to figure out oh is this ground mobile so it’s bouncing around? Is this in a cargo application? Is this in an aircraft? Is it shipborne?
So what is it that you’re trying to test? At Crystal Group we took a little bit different approach to this. What we did was combine several different categories. For instance we might take the power spectro density associated with C-17, which is a very broad spectrum, general turbine engine noise and we might overlay the propeller blades of a C-130 on top of that. And then we might throw in the ground mobile types of vibration that you see in some of the lower frequencies. And then on top of that we might put in something like the Blackhawk. And combine all those profiles together.
What that allows up to do is we get qualified for all those different platforms using one test. So while it’s a little bit of the worst case it really does provide us with the opportunity to build a more robust product, a product that doesn’t crack solder joints, a product that has a longer life and a product that can withstand field service and be there for the warfighter when they need it. That’s our approach it’s a little bit conservative but what it does do it provides a better product in the end. So we are pretty hard on ourselves in terms of making sure that’s the standard that we hold ourselves to. And it bares fruit in terms of the reliability and the uptime or the availability of the product in the field.
The other thing that I would mention about MIL-STD-810, in procedure 514 is there a lot of information in there. You have an entire tailoring section, which is Annex A and then there’s an also an engineering resource in Annex B. This is definitely a rabbit hole that you can get down into. For those of us that are mechanical engineers or aerospace engineers is very interesting. So it’s one of those things where you’ve got a lot of information but we tend to take a look at it from the standpoint of how do we maintain our robust product, how do we make sure that it’s going to last out in the field. That’s our focus when we look at vibration here at Crystal Group. Thanks a lot.