MIL-STD-810 Vibro-Acoustic Temperature test

As a MIL-STD-810G certified lab, we realize the importance of vibro-acoustic shock testing. Meeting the MIL-STD-810 standard requirements can be difficult. We understand the challenges and guide companies through the process.

Keystone Compliance creates an accurate test plan to eliminate expensive over-testing. We have a reputation of helping customers achieve their MIL-STD product certifications. Our accurate test reports are delivered quickly. We are in constant communication throughout the entire test process. Keystone provides comprehensive reports shortly after completion of the MIL-810 standard testing.

Request a quote to learn why we are one of the fastest growing compliance test labs in the country. Have a question about environmental condition testing? Contact us or call (724) 657-9940 and we will determine the best course of action.

The Importance of Vibro-Acoustic/Temperature Testing

There are five main determinations of the vibro-acoustic/temperature method 523 procedure. Its main purpose is to discover the synergistic effects on externally carried aircraft stores during captive carry flights. This is useful to:

  • Reveal and correct design weaknesses
  • Determine whether a design meets specified reliability criteria
  • Reveal workmanship or component defects before a production unit leaves the assembly facility
  • Estimate the Mean Time Between Failure (MTBF) of a lot of units based upon the test item’s time to failure of a small sample of units
  • Determine the relative reliability among units based upon the test item’s failure of a small sample of the units.

This MIL-STD 810 compliance method is primarily intended to test electronics within the store for functionality in a vibro-acoustic/temperature environment. Typical applications also include the development of a more reliable design prior to production. Lastly, it determines the acceptance of a lot prior to delivery.

How Vibro-Acoustic/Temperature Compliance Testing Affects Products

After examining the requirements, the following will help determine where vibro-acoustic/temperature environments are foreseen in the life cycle of the material. Possible effects include all effects that these factors can cause separately (810-test method 514, 515 and 520).

Increased stress as a result of moisture from thermal change may produce possible effects. The combined vibration, acoustic noise, and temperature environments may interact to produce effects that would not occur in any single environment.

Not all environmental stresses contribute equally to decline or failure. The loading of stores through captive carriage, temperature, vibration, and moisture are four of the most important causes of failure within a material. 

Information on the Vibro-Acoustic/Temperature Lab Testing Standard

This method only includes one procedure that may be tailored to many test reports.  Variables that may be adjusted within the tailoring process include temperature, moisture, shock, vibration, altitude and other environments.

Temperature – The most severe temperature shock may come from powering material when it is cold, thus, variations of this variable include ambient temperature, aerodynamic heating, power dissipation and temperature gradients.

The greatest variations in ambient temperature occur near the surface of the earth. It is important to consider on-the-ground temperature in determining the initial captive flight temperature. Aerodynamic heating can be described as the high convective heat transfer rate that will cause surface temperatures of an external store to be near that of the boundary layer. Lastly, the strongest temperature gradients will usually be those associated with powering the material when it is cold.

Vibration – Vibration can cause failure of parts, abrasion due to relative motion, dislodging of loose particles, and etc. The two types of vibration that will arise in this method are low and high frequency vibration.

The low frequency vibration primarily stresses the structure of the material and is driven by transmission from the aircraft. High frequency vibration is driven by the boundary layer turbulence. This vibration does not contribute to failure of basic structure but often failure in electronics.

Moisture – Moisture, in conjunction with soluble contaminants can cause corrosion. Freezing water in confined spaces may produce mechanical stress. Thus, the test cycle should provide for diffusion of water vapor and condensation. This MIL-810 test is not suitable for corrosion tests such as the humidity or salt fog test (method 507 and 509).

Shock – Shock can cause failure through mechanical stress similar to that induced by vibrations. Shocks that are more transient may be included in this test. Account for events that are potentially destructive to electronics in other analyses and tests.

Altitude – Barometric pressures are generally not a stress for external stores. However, the change in pressure may enhance the penetration by moisture. Reduced pressure may also increase the temperature due to reduced power dissipation, which may also lead to increased electrical arcing. 

Limitations of Test Method 523, Vibro-acoustic/Temperature Test

This MIL-STD-810 test method is not intended for a number of reasons. Tailoring is essential. Select the procedures and parameters based on the process described above. Some military standard test limits include, but are not limited to:

  • An environmental design qualification test of a store or any of its individual components for functionality
  • An environmental design qualification test of a store airframe or other structural components for structural integrity.
  • Any MIL-STD 810 test to satisfy the requirements of the Life Cycle Profile except that for combined vibration, acoustic, and temperature environments related to reliability testing.

Keystone Compliance Provides Professional Vibro-Acoustic/Temperature Testing

Keystone Compliance is one of the best MIL-810 Standard and Vibro-Acoustic Temperature labs in the country. We employ expert test engineers and properly equip our military testing lab in order to provide MIL-STD-810 certifications.

Keystone has a full lab of test equipment which permits us to provide short lead times on scheduling. In addition to MIL-STD-810 vibro-acoustic temperature testing, our team strives to give our customers more time and energy on product development instead of testing.

Request a quote and learn why so many manufacturers rely on Keystone Compliance to meet their MIL-810 Vibro-Acoustic/Temperature test and MIL-STD 810 lab compliance testing needs.