MIL-STD-810 Pyroshock Testing at Accredited Lab

MIL-STD 810 Method 517 Pyroshock Testing is performed to evaluate whether products can withstand the shock effects caused by the detonation of a pyrotechnic device, typically found in missiles or rockets. A pyroshock test can also be used to determine an item’s fragility level experimentally. This allows for the application of shock mitigation techniques to protect its structural and functional integrity. The latest revision of this test standard is Method 517.3 from MIL-STD-810H.

DES is a leader in MIL-STD-810 Pyroshock testing, having performed hundreds of tests using our state-of-the-art Mechanical Impulse Pyroshock Simulator (MIPS).

Understanding Pyroshock

A pyroshock creates a stress wave that propagates through the structure into components that are mounted to the structure. A Pyroshock has the following characteristics:

Frequency range from 100 Hz up to 10,000 Hz and beyond
High accelerations from 300 G’s up to 200,000 G’s with low structural velocity and displacement response
Short-time durations less than 20 milliseconds

Common Failures caused by Pyroshock Impulses?

Destruction of the structural integrity of micro-electronic chips
Electrical relay chatter causing operational faults
Circuit board malfunction and/or damage
Electronic connector failure or momentary disconnects
Cracks and fractures in crystals, ceramics, epoxies, or glass envelopes

Pyroshock definitions are from MIL-STD-810H, Method 517.3

Near-field Pyroshock. The stress wave propagation effects govern the response. Near-field pyroshock tests require frequency control up to and above 10,000 Hz for amplitudes greater than 10,000G’s. A pyrotechnically excited simulation is mostly used, although in some cases a mechanically excited simulation technique may be used.
Mid-field Pyroshock. The pyroshock response is governed by a combination of material stress wave propagation and structural resonance response effects. Mid-field pyroshock tests require frequency control from 3,000 Hz to 10,000 Hz for amplitudes less than 10,000G’s. A mechanically excited simulation technique other than shaker shock is typically used.
Far-field Pyroshock. The pyroshock response is governed by a combination of material stress wave propagation and structural resonance response effects. Far-field pyroshock tests require frequency control no higher than 3,000 Hz for amplitudes less than 1,000G’s. An electro dynamic shaker or a mechanically excited simulation technique is typically used.

Method 517.3 Pyroshock has Five Testing Procedures:

Procedure I – Near-field with an Actual Configuration. For Procedure I, the pyroshock is replicated using the actual material and the associated pyrotechnic shock test device configuration.
Procedure II – Near-field with a Simulated Configuration. Procedure II replicates the pyroshock using the actual material, but the associated pyrotechnic shock test device is isolated from the test item. For example, by being mounted on the back of a flat steel plate.
Procedure III – Mid-field with a Mechanical Test Device. For Procedure III, replication of the pyroshock is performed using a mechanical device that simulates the pyroshock peak acceleration amplitudes and frequencies. A mechanical device such as DES’s MIPS is used. An electrodynamic shaker is not capable because of frequency range, peak acceleration and weight limitations.
Procedure IV – Far-field with a Mechanical Test Device. Procedure IV also replicates the pyroshock with a mechanical device such as DES’s MIPS. An electrodynamic shaker is not capable of performing Procedure IV pyroshocks because of limitations.
Procedure V – Far-field with an Electrodynamic Shaker. The pyroshock is replicated using an electrodynamic shaker to simulate the low frequency structural resonant response.

How MIL-STD-810 Pyroshock Testing is Performed at DES?

The pyroshock test criteria, including the required Shock Response Spectrum (SRS), are provided to DES. A specialized fixture is then fabricated to attach to our shock test equipment. The test setup is experimentally determined using a mass model to achieve the required SRS. Once the SRS is replicated with the mass model, the actual test item is tested on the shock apparatus. The shock pulse is captured using high-speed data acquisition and specialized shock accelerometers, with SRS plots calculated and analyzed using our specialized software.

The testing is performed along 3 orthogonal axes. In most cases, the required SRS is achieved in both positive and negative directions during a single strike. Upon test completion, DES promptly delivers a detailed report that includes pyroshock plots, test observations, results, and color photographs of the setup and any failures.

Why Choose DES for MIL-STD-810 Pyroshock Testing

When it comes to MIL-STD-810 Pyroshock Testing, selecting the right laboratory is crucial for repeatable results. DES stands out because:

DES has performed hundreds of Pyroshock tests for defense and space manufacturers
Our lab is A2LA accredited to MIL-STD-810, Method 517 Pyroshock Testing
We utilize state-of-the-art Mechanical Impulse Pyroshock Simulator (MIPS) capable of performing MIL-STD-810 Pyroshock testing
Our high speed data acquisition captures the shock pulse and has specialized accelerometers rated for pyroshock testing