MIL-STD 810 Shock Testing
MIL-810 shock tests are performed in military shock labs. They provide confidence that material can withstand the shocks encountered in handling, transportation, and service environments. Military shock testing includes an assessment of the overall material system integrity. It ensures safety in the handling, transportation, and/or service environments, and helps determine the material’s fragility level.
Due to packaging, stowage, or mounting configurations may be designed to protect the material’s physical and functional integrity. Shock testing helps determine the strength of the devices that secure items to platforms, which could be involved in a crash. It verifies that the material itself is not hazardous and that parts of the material are not ejected during a crash.
Keystone Compliance is a shock testing lab with significant MIL-STD 810H mechanical shock and vibration testing experience. Our mechanical shock lab is perfect for all your shock compliance needs. Our test engineers have an in-depth knowledge of MIL-810H and MIL-810G shock testing.
The following information is extremely technical in nature. It provides a summary of Method 516.8 shock testing, as derived from the MIL-STD 810H shock section. Even though the language is from MIL-810H shock, it applies previous versions of the standard. This includes military standards like MIL-STD 810G shock.
What are the Effects of MIL-STD 810 Shock Testing on the Test Material?
Mechanical shock has the potential for producing adverse effects on the physical and functional integrity of material. In general, the damage potential is a function of the amplitude, velocity, and duration of the shock. Adverse effects on the materials overall integrity are magnified when shocks frequency content’s correspond with the material’s natural frequencies.
The material response to the mechanical shock environment will, in general, be highly oscillatory. It will have a short duration, and a substantial initial rise time. This will include large positive and negative peak amplitudes. The peak responses of material to mechanical shock will, generally, be enveloped by a decreasing form of exponential function in time.
In general, mechanical shock applied to a complex multi-modal material system will cause the material to respond to two things. First to forced frequencies of a transient nature imposed on the material from the external excitation environment. Second to the material’s resonant natural frequencies either during or after application of the external excitation environment.
Such a response could lead to several issues including:
- Material failure, because of increased or decreased friction between parts, or general interference between parts.
- Changes in material dielectric strength, loss of insulation resistance, and/or variations in magnetic and electrostatic field strength.
- Materiel electronic circuit card malfunction, electronic circuit card damage, and electronic connector failure. On occasion, circuit card contaminants having the potential to cause short circuit may be dislodged under material response to shock.
- Permanent mechanical deformation of the material because of overstress of material structural and non-structural members.
- Collapse of mechanical elements of the material because of the ultimate strength of the component being exceeded.
- Accelerated fatiguing of materials a.k.a. low cycle fatigue.
- Potential piezoelectric activity of materials.
- Material failure because of cracks in fracturing crystals, ceramics, epoxies, or glass envelopes.
What is the Proper Test Procedures for the Best Shock Testing?
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|VIII||Catapult Launch/Arrested Landing||✓||✓||✓|
How Do These Test Methods Differ from One Another?
Procedure I – Functional Shock is intended to test material in its functional mode. It also assesses the physical integrity, continuity, and functionality of the material to shock.
In general, the material is required to function during and after the shock. It must survive without damage resulting from shocks representative of those that may be encountered during operational service. Test materials may be mechanical, electrical, hydraulic, and electronic.
Procedure II – Transportation Shock is used to evaluate the response of an item or restraint system to a repetitive shock load. The procedure uses a classical terminal peak sawtooth, either measured or a synthetic shock waveform. This represents the shock excitation portion of the transportation scenario.
The shock can be a repetitive event of similar amplitude, or an irregular event that varies in amplitude and frequency bandwidth. Ground vehicle transportation is a common source for transportation shock.
Procedure III – Fragility is used early in the item development program to determine the material’s fragility level. This is so packaging, stowage, or mounting configurations may be designed to protect the material’s physical and functional integrity.
This procedure determines the critical shock conditions at which there is a chance of structural and/or operational system degradation. It is based upon a systematic increase in shock input magnitudes. To achieve the most realistic criteria, perform the procedure at environmental temperature extremes.
Procedure IV – Transit Drop is a physical drop test. It is intended for material either outside of, or within its transit or combination case, or as prepared for field use. This procedure is used to determine if the material is capable of withstanding the shocks normally induced by loading and unloading.
It takes into account when material is outside of its transit or combination case. Like during routine maintenance, when being removed from a rack, being placed in its transit case, etc. It also takes into account when material is inside its transit or combination case. Such shocks are accidental, but may impair the functioning of the material.
Procedure V – Crash Hazard Shock Test is for material mounted in air or ground vehicles. This material could break loose from its mounts, tiedowns, or containment configuration during a crash. This would present a hazard to vehicle occupants and bystanders. This procedure is intended to verify the structural integrity of material mounts, tiedowns or containment configuration during simulated crash conditions.
Use this test to verify the overall structural integrity of the material. In some instances, the crash hazard can be evaluated by a static acceleration test, or a transient shock. The requirement for one or both procedures must be evaluated based on the test item.
Procedure VI – Bench Handling is intended for material that may typically experience bench handling, bench maintenance, or packaging. It is used to determine the ability of the material to withstand representative levels of shock encountered in such environments. This procedure is appropriate for material out of its transit or combination case.
Such shocks might occur during material repair. This procedure includes testing for material with protrusions that may be damaged without regard to gross shock on the total material. The nature of such testing must be performed on a case-by-case basis. The configuration of material protrusions, and case scenarios for damage during bench handling, maintenance, and packaging are evaluated case-by-case.
Procedure VII – Pendulum Impact is intended to test the ability of large shipping containers to resist horizontal impacts. It determines the ability of the packaging and packing methods to provide protection to the contents when the container is impacted.
This test is meant to simulate accidental handling impacts. It is used only on containers that are susceptible to accidental end impacts. The pendulum impact test is designed specifically for large and/or heavy shipping containers. These are likely to be handled mechanically rather than manually.
Procedure VIII – Catapult Launch/Arrested Landing is intended for material mounted in or on fixed-wing aircraft. It is subject to catapult launches and arrested landings.
For catapult launch, material may experience an initial shock. This is followed by a low level transient vibration, concluded by a final shock according to the catapult event sequence. For arrested landing, material may experience an initial shock followed by a low level transient vibration.
What Shock Laboratory Should You Trust?
Looking to get a shock certification for your product? Contact Keystone Compliance today to work with an expert who understands the requirements of military shock testing standards like MIL-STD-810 shock. Keystone has military shock and vibration labs, functioning to ensure optimal performance. Talk to our experts to develop a streamlined test plan and receive a professional and affordable quote.
As an expert in shock certification, Keystone Compliance has been recognized as one of the best shock labs in the country. Our capabilities include testing to commercial and military shock testing standards. Contact us to learn why so many manufacturers rely on Keystone Compliance to meet their shock and vibration testing needs.
There have been several versions of shock testing procedures in MIL-STD-810 shock testing. Below is a list of each version and the appropriate method number:
- MIL-STD-810A Test Method 516 Shock Testing
- MIL-STD-810B Test Method 516 Shock Testing
- MIL-STD-810C Test Method 516.2 Shock Testing
- MIL-STD-810D Test Method 516.3 Shock Testing
- MIL-STD-810E Test Method 516.4 Shock Testing
- MIL-STD-810F Test Method 516.5 Shock Testing
- MIL-STD-810G Test Method 516.6 Shock Testing
- MIL-STD-810H Test Method 516.8 Shock Testing