This is part one of a series of blog posts discussing MIL-STD 810 Vibration Testing. This blog was written with reference to MIL-STD-810G w/Change 1 dated 15 April 2014. DES has the experience and expertise to help you determine what profiles are appropriate for your product and to run your MIL-STD-810 vibration test. Check out our vibration testing capabilities here.
MIL-STD-810 is a public military test standard that is designed to assist in the environmental engineering considerations for product design and testing. For the purposes of this blog series we will focus on Method 514.7, titled Vibration. This section defines the environmental vibration conditions a material or product may experience during the product life cycle and translates these conditions into replicable test procedures. Unfortunately, unless you’re familiar with this document, this section or any section for that matter may seem a little daunting. This blog will hopefully provide some guidance into navigating your way through it.
The best place to start is Table 514.7-I which can be found shortly after the table of contents of Method 514.7. This table basically acts as a summary for the section and directs you to the specific annex to look for the applicable environmental vibration category for your product. Before you jump to the test profiles, there are some definitions and details worth pointing out. The different types of test procedures, called out in the last column of the table, are defined further on in this section. This is important because some of the test procedures require different or unusual test setups which may be more suitable to your product’s environmental vibration exposure.
Test I: General Vibration
This condition applies to material/products “to be transported as secured cargo or deployed for use on a vehicle. This procedure applies to ground vehicles as well as fixed and rotary wing aircraft. For this procedure, the test item is secured to a fixture or a vibration exciter, and vibration is applied to the test item as an input.
Test II: Loose Cargo Transportation
This condition applies to material/products “to be carried in/on trucks, trailers, or tracked vehicles and not secured to (tied down in) the carrying vehicle. The test severity is not tailorable, and represents loose cargo transport in military vehicles traversing rough terrain.” Essentially, worst case scenario. For this procedure, the test item is not secured to the vibration exciter, and is free to move during the test. Typically a fence is built around the vibration table to prevent the product from falling off of the table.
Test III: Large Assembly Transportation
This condition applies to “large assemblies of material installed or transported by wheeled or tracked vehicles. It is applicable to large assemblies or groupings forming a high proportion of vehicle mass, and to materiel forming an integral part of the vehicle.”
Test IV: Assembled Aircraft Store Captive Carriage and Free Flight
This condition applies to “fixed wing aircraft carriage and free flight portions of the environmental life cycles of all aircraft stores, and to the free flight phases of ground or sea-launched missiles.”
Test procedures I and IV use standard laboratory vibration shakers while test procedures II and III require more specialized equipment. For the most part, most of the categories in Table 514.7-I call for test procedures I and IV which most test laboratories should have and therefore can be configured to those test profiles.
Once you have determined the application type and test procedure your product/material falls under, you can move on to determining your test profile. There are a variety of types of vibration profiles that are defined in Annexes B through E of MIL-STD-810 depending on the expected environmental vibration exposures of your product. General definitions of the different types of vibration profiles can be found in Annex A of MIL-STD-810G Change 1, Method 514.7, however, more detailed understanding of sinusoidal, random and mixed vibration profiles can be found in the associated links as well as below.