RVSS may be performed at any indenture level, provided an
effective input stimulus (as defined in section 1) to the PWAs is
The acceleration spectrum shall be calculated to determine the
maximum allowable Power Spectral Density (PSD) level for each unique
PWA regardless of the indenture level for applying RVSS.
The values calculated shall be proof tested on actual hardware to
determine if the input stimulus to the PWA is at or below a level
that would result in equipment degradation.Proof testing should not
damage good hardware.
If the calculated maximum allowable PSD level is below the starting
PSD profile, as shown in Figure 2-3, a corrective
action plan shall be submitted for approval by NAVSEA before the
start of the ESS program.As a minimum, this plan shall address
proposed means to increase RVSS input (e.g. removal of heavy parts
prior to RVSS or the use of a bonding agent, etc.), and RVSS
effectiveness if corrective action is not implemented.
The acceleration spectrum applied at the module and/or higher levels
of indenture shall not be below Figure 2-3 due to a
minority of PWA’s whose design is limiting the input. Removal of
these minority PWAs resulting in increased module or higher indenture
level screening effectiveness is suggested. In this case, minority
PWAs would be screened separately at their limiting vibration
Combining PWAs of similar PSD levels together to optimize effectiveness