SRS Shaker Shock and Pyroshock Testing
SRS Shock tests are specified in the Frequency Domain in terms of acceleration (G) vs. frequency (Hz) and typically are associated with high-g environments caused by severe impacts, explosive events, etc. SRS (shock response spectrum) transient shocks incorporate a broad range of frequencies into the test pulse which better approximate the real mechanical event. SRS shock is sometimes called “Pyroshock” because the high-G environment being simulated is often generated by an explosion (pyrotechnic event).
SRS Pyroshock testing is commonly used to determine a test article’s ability to tolerate the mechanical stress waves produced by a high frequency, high-G shock event, such as rocket stage separations. SRS pyroshock specs are found in most aerospace hardware test procedures, given as a graph profile showing “response” acceleration (g) on the Y-axis and frequency (Hz) on the X-axis. The Y-axis acceleration values represent the profiled g-level measured by a set of analysis filters that have a specified gain, or Q factor (Q = 10 typical).
Experior Laboratories uses Unholtz-Dickie T-2000 vibration systems optimized for high G shaker shock up to 5,000 G. Unholtz-Dickie vibration systems have inductively coupled solid metal coil armatures to prevent driver coil failure. Shakers with 3” stroke and 180 in/s of velocity allow for high G shock tests with large displacement requirements or short transients.
For near or midfield Pyroshock or SRS Shock requirements that exceed the limits of an electrodynamic shaker, Experior Laboratories uses a custom Kinetic Impact Pyroshock Simulation system which allows highly customizable shock generation at levels in excess of 30,000 G.
Our Kinetic Impact Pyroshock Simulation (KIPS) test system is able to simulate near and mid field Pyroshock, experienced by the parts closest to a pyrotechnic event, by using high speed impact to excite a tunable resonant beam. By adjusting the impact force, location, and damping, this platform allows for highly customizable shock generation. Our pneumatic system allows for quick setup and resets, and means we don’t have to charge ‘per shock’ to get a custom shock profile right.
Adjustable resonance allows us to boost acceleration in only the desired frequency range. For shocks with a specified Te (event duration), adjustable muzzle velocity, impact mass, and custom damping materials allow us to customize shock duration while meeting acceleration requirements.
The KIPS system boasts short transients, narrow differences between positive and negative SRS traces, and a uniform shock input that allows for near-equal measurements at multiple fixture mounting points. We’ve designed a wide variety of custom shock platforms and fixtures using frequency analysis software to identify mode shapes and resonant frequencies, which lets us prevent cross-axis acceleration and ensure that units are not over-tested.