Estimating Shock Severity
The recently issued specification ANSI/ASA S2.62-2009, Shock Test Requirements for Equipment in a Rugged Shock Environment, specifies shock severity levels according to the plateau level on the PVSS plotted on 4CP, (pseudo velocity shock spectrum plotted on four coordinate paper). The levels run from 1 - 10 meters per second or 40 to 400 ips. These ANSI levels provide an example of how to identify shock severity. Examples are plotted of both PVSSs and SRSs divided by 2 pi f, to form an acceleration PVSS or APVSS on 4CP. These show that the plateau of the APVSS is the same as the PVSS. Thus published SRSs can be evaluated with constant velocity lines drawn on the SRS which also show the severe frequency range. The paper shows severity levels of many SRSs. Several pyroshock references that refer to plateau severities of 50 ips as very mild, 100 ips as moderate, and 300 ips as very severe are examples.
KeywordsPeak Acceleration Modal Stress Plateau Level Modal Velocity Shock Severity
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