This study evaluates the vibration isolation effect of
various mounting systems in a heavy freight locomotive
cab, and provides an analytical method for the prediction
of structural vibration. The cab is set up in a controlled
laboratory environment in a manner similar to the installation
on a locomotive. Field measurements are used to emulate
actual vibration input to the cab structure. A 16-channel
data acquisition system is used to collect vibration data
at various points on and inside the cab structure.
The cab was isolated from the sill structure through six
elastomeric mounts fixed at the base of the cab and at the
crash posts. The mounts at the base were selected such that
they support the static weight of the cab and offer good
lateral and longitudinal stability. Two cylindrical elastomeric
mounts were placed between the cab structure and the crash
posts which attach to the front of the sill structure.
Upon establishing the baseline for laboratory vibration
measurements and correlating them with field data,
acceleration data was collected at discrete locations, both
inside and outside of the cab. The data was used in
conjunction with an analytical formulation to generate
vibration approximations of the discrete locations. To validate
the analytical approximations, experimental results were
compared with the analytical predictions using simulated
field input to the cab.
The test results from the analytical model approximations
proved to have a strong correlation with experimental results.
Vibration approximations of locations outside the cab had a
higher correlation to the experimental data than the points
on the inside. Although the model did not yield exact results
for several positions inside the cab, it resulted in several
recommendations for future work.
