MIL-STD-810 Shock Methods and Procedures
MIL-STD-810 contains numerous shock methods and procedures. This is because the types of shock likely to be encountered during a product’s logistic, tactical, and operational service life are substantial. MIL-STD-810 therefore, must contain multiple methods and procedures to simulate these events in laboratory testing. To ensure effective developmental test and evaluation of a product it is important to understand these types of shocks, their characteristics, and how they could potentially effect the product to be tested. Methods for evaluation include:
- Gunfire Shock
- Ballistic Shock
- Rail Impact
Within most of these methods various procedures are contained to further complicate the issue. Method 516.8 Shock has eight different procedures these procedures include:
- Functional Shock
- Transportation Shock
- Transit Drop
- Crash Hazard Shock
- Bench Handling Shock
- Pendulum Impact
- Catapult Launch/Arrested Development
Choosing Appropriate MIL-STD-810 Shock Methods
Because time and money are limited resources, decisions must be made as to which testing will be performed. While requirements can offer a degree of clarity into relevant test methodology selection, a thorough assessment must be made through a Life Cycle Environmental Profile (LCEP) to develop an effective test matrix. The LCEP will map all anticipated logistical, tactical, and operational shock events and offer appropriate parameters for test selection and severity. These inputs combined with requirements and measured data are then placed into an Environmental Issues/Criteria List (EICL). Selection can then be made based on a risk assessment of vulnerabilities of the product based and probability of an environmental stress to occur.
Characteristics of Shock Types
Mechanical shock are generally events that have a short duration of under a second and are usually limited in frequency below 4 kHz. Other types of shock such as Pyroshock (Pyrotechnic Shock) , Ballistic Shock, and Shipboard Shock (MIL-DTL-901) can have much higher frequency components. Pyroshocks, for example, typically are less than 20 msec. in duration with a frequency range of 100 Hz to 1 MHz. Higher frequency shock events pose a greater threat to smaller electronic components and can cause intermittent failures due to relay chatter and piezoelectric effects. Therefore consideration must be given to the test items vulnerabilities to shock frequency content as well as g forces.
Making the Decisions
MIL-STD-810 provides guidance for selection of appropriate test methodologies. This allows for the development of systems in a timely fashion without excessive testing and over engineering. When selecting, for example, appropriate scenarios for Transport Drop for Tactical situations, look at those with the greatest impact velocity and then make a risk assessment as to which of these would pose the greatest threat to the test item based on the probability of an event to occur.
CVG Strategy Can Help
Our team of test and evaluation experts can assist you in creating a meaningful test program that meets requirements and prevents costly failures at the operational test stage. CVG Strategy provides an array of services to help you with environmental and EMI/EMC testing. We also offer classes in MIL-STD-810 to help you keep current with the latest developments in this important standard.