Rugged by Design - Validated Rugged from the Ground Up

ADLINK VPX blade hardware designs are validated to meet MIL-STD-810G shock and vibration requirements during the development process, including:

MIL-STD-810G, Method 516.6, Procedure I - Functional Shock (40g shock)
MIL-STD-810G, Method 516.6, Procedure V - Crash Hazard Shock Test (75g shock)
MIL-STD-810G, Method 514.6, Annex C, Category 7 - Vibration: Jet Aircraft
MIL-STD-810G, Method 500.5, Procedure II - Low Pressure Altitude
MIL-STD-810G, Method 501.5, Procedure II - High Temperature
MIL-STD-810G, Method 502.5, Procedure I and II - Low Temperature
MIL-STD-810G, Method 503.5, Procedure I - Thermal Shock

The following descriptions are extracts from the "MIL-STD-810G, Department of Defense Test Method Standard: Environmental Engineering Considerations and Laboratory Tests", available from the Defense Technical Information Center (DTIC) at www.dtic.mil.

1. MIL-STD-810G, Method 516.6, Procedure I - Functional Shock (40g shock)
2. MIL-STD-810G, Method 516.6, Procedure V - Crash Hazard Shock Test (75g shock)

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Shock tests are performed to:

provide a degree of confidence that materiel can physically and functionally withstand the relatively infrequent, non-repetitive shocks encountered in handling, transportation, and service environments. This may include an assessment of the overall materiel system integrity for safety purposes in any one or all of the handling, transportation, and service environments;
determine the materiel's fragility level, in order that packaging may be designed to protect the materiel's physical and functional integrity; and
test the strength of devices that attach materiel to platforms that can crash.

Procedure I - Functional Shock

Procedure I is intended to test materiel (including mechanical, electrical, hydraulic, and electronic) in its functional mode and to assess the physical integrity, continuity and functionality of the materiel to shock. In general, the materiel is required to function during the shock and to survive without damage to shocks representative of those that may be encountered during operational service.

Procedure V - Crash Hazard Shock Test

Procedure V is for materiel mounted in air or ground vehicles that could break loose from its mounts, tiedowns or containment configuration during a crash and present a hazard to vehicle occupants and bystanders. This procedure is intended to verify the structural integrity of materiel mounts, tiedowns or containment configuration during simulated crash conditions. Use the test to verify the overall structural integrity of the materiel, i.e., parts of the materiel are not ejected under the shock. This procedure is not intended for materiel transported as cargo for which Method 513.6, Acceleration, or Method 514.6, Vibration, could be applied. The crash hazard can be evaluated by a static acceleration test (Method 513 Procedure III) and/or a transient shock (Method 516 Procedure V). The requirement for one or both procedures must be evaluated based on the test item.

3. MIL-STD-810G, Method 514.6, Annex C, Category 7 - Vibration: Jet Aircraft

Cargo vibration environments on jet aircraft are broadband random in nature. The maximum vibrations are usually engine exhaust noise generated and occur during takeoff. Levels drop off rapidly after takeoff to lower level cruise levels that are boundary layer noise generated.

Low frequency vibration. Vibration criteria typically begins at 15 Hz. At frequencies below 15 Hz, it is assumed that the cargo does not respond dynamically. Airframe low frequency vibration (gust response, landing impact, maneuvers, etc.) is experienced as steady inertial loads (acceleration).
Large cargo items. Cargo items that are large relative to the airframe in dimensions and/or mass may interact with aircraft structural dynamics. This is particularly true if the materiel has natural frequencies below 20 Hz. This interaction may have serious consequences with regard to aircraft loads and flutter. Evaluate materiel that fits this description by the aircraft structural engineers prior to carriage. Contact the Aircraft Product Center Wings responsible for the aircraft type for this evaluation.
Exposure levels.
- Vibration qualification criteria for most jet cargo airplanes are available through the Aircraft Product Center Wings responsible for the aircraft type. These criteria are intended to qualify materiel for permanent installation on the airplanes and are conservative for cargo. However, function criteria for materiel located in the cargo deck zones can be used for cargo if necessary.
- Based on the worst case zone requirements of the most common military jet transports, so that even though it does not envelope all peaks in the various spectra, it should still be mildly conservative for cargo. Also, since it does not allow the valleys in the individual spectra, it should cover other jet transports with different frequency characteristics. The envelope represents take-off, the worst case for cargo. Vibration during other flight conditions is substantially less.
Exposure durations. Select a duration of one minute per takeoff. Determine the number of takeoffs from the Life Cycle Environment Profile.

4. MIL-STD-810G, Method 500.5, Procedure II - Low Pressure Altitude
Use low pressure (altitude) tests to determine if materiel can withstand and/or operate in a low pressure environment and/or withstand rapid pressure changes.

Use this method to evaluate materiel likely to be:

stored and/or operated at high ground elevation sites.
transported or operated in pressurized or unpressurized areas of aircraft (also consider method 520 for actively-powered materiel operated at altitude).
exposed to a rapid or explosive decompression and, if so, to determine if its failure will damage the aircraft or present a hazard to personnel.
carried externally on aircraft.

Effects of low pressure environments.

Physical/chemical.

Leakage of gases or fluids from gasket-sealed enclosures.
Deformation, rupture or explosion of sealed containers.
Change in physical and chemical properties of low-density materials.
Overheating of materiel due to reduced heat transfer.
Evaporation of lubricants.
Erratic starting and operation of engines.
Failure of hermetic seals.

Electrical. Erratic operation or malfunction of materiel resulting from arcing or corona.

5. MIL-STD-810G, Method 501.5, Procedure II - High Temperature

Use high temperature tests to obtain data to help evaluate effects of high temperature conditions on materiel safety, integrity, and performance. Use this method to evaluate materiel likely to be deployed in areas where temperatures (ambient or induced) are higher than standard ambient.

Effects of high temperature environments.

High temperatures may temporarily or permanently impair performance of materiel by changing physical properties or dimensions of the material(s) of which it is composed. The following are examples of problems that could result from high temperature exposure that may relate to the materiel being tested. Consider the following typical problems to help determine if this method is appropriate for the materiel being tested. This list is not intended to be all-inclusive.

Parts bind from differential expansion of dissimilar materials.
Lubricants become less viscous; joints lose lubrication by outward flow of lubricants.
Materials change in dimension, either totally or selectively.
Packing, gaskets, seals, bearings and shafts become distorted, bind, and fail causing mechanical or integrity failures.
Gaskets display permanent set.
Closure and sealing strips deteriorate.
Fixed-resistance resistors change in values.
Electronic circuit stability varies with differences in temperature gradients and differential expansion of dissimilar materials.
Transformers and electromechanical components overheat.
Operating/release margins of relays and magnetic or thermally activated devices alter.
Shortened operating lifetime.
Solid pellets or grains separate.
High pressures created within sealed cases (projectiles, bombs, etc.).
Accelerated burning of explosives or propellants.
Expansion of cast explosives within their cases.
Explosives melt and exude.
Discoloration, cracking or crazing of organic materials.
Out-gassing of composite materials.

6. MIL-STD-810G, Method 502.5, Procedure I and II - Low Temperature

Use low temperature tests to obtain data to help evaluate effects of low temperature conditions on materiel safety, integrity, and performance during storage, operation, and manipulation.

Use this method to evaluate materiel likely to be deployed in a low temperature environment during its life cycle and the effects of low temperature have not been assessed during other tests (e.g., a temperature-altitude test).

While all procedures involve low temperatures, they differ on the basis of the timing and nature of performance tests.

Procedure I - Storage. Use Procedure I to investigate how low temperatures during storage affect materiel safety during and after storage, and performance after storage.
Procedure II - Operation. Use Procedure II to investigate how well the materiel operates in low temperature environments. For the purpose of this document, operation is defined as excitation of the materiel with a minimum of contact by personnel. It does not exclude handling (manipulation).

7. MIL-STD-810G, Method 503.5, Procedure I - Thermal Shock

Use the temperature shock test to determine if materiel can withstand sudden changes in the temperature of the surrounding atmosphere without experiencing physical damage or deterioration in performance. For the purpose of this document, "sudden changes" is defined as "an air temperature change greater than 10°C (18°F) within one minute."

Normal environment.

Use this method when the requirements documents specify the materiel is likely to be deployed where it may experience sudden changes of air temperature. This method is intended to evaluate the effects of sudden temperature changes of the outer surfaces of materiel, items mounted on the outer surfaces, or internal items situated near the external surfaces. This method is, essentially, surface-level tests. Typically, this addresses:

The transfer of materiel between climate-controlled environment areas and extreme external ambient conditions or vice versa, e.g., between an air conditioned enclosure and desert high temperatures, or from a heated enclosure in the cold regions to outside cold temperatures.
Ascent from a high temperature ground environment to high altitude via a high performance vehicle (hot to cold only).
Air delivery/air drop at high altitude/low temperature from aircraft enclosures when only the external material (packaging or materiel surface) is to be tested.

Safety and screening.

Except as noted in paragraph 1.3, use this method to reveal safety problems and potential flaws in materiel normally exposed to less extreme rates of temperature change (as long as the test conditions do not exceed the design limitations of the materiel).