Page 58 - Shock and Vibration Overview
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Simulating Shock & Vibrations in the Laboratory
Their shakers may also work as general vibration and shock exciters for smaller systems
to qualify your product/design as shown in Figure 42; but their equipment is best suited
for smaller test setups and/or modal testing.
Figure 42: The Modal Shop’s general purpose vibration shakers performance range is dependent
on payload mass and maximum acceleration levels desired.
Another form of exciting your structure for the purpose of modal testing is using an
impact hammer. These offer a much more cost effective means of performing your
testing (a typical impact hammer will cost just under $1,000) and are the preferred
method for many experts. An impact hammer will provide a nearly constant force over a
broad range of frequencies (specified by the type of tip you use); and therefore these
are capable of exciting a broad range of resonances and modal shapes. These hammers
will come force-instrumented so that the frequency response function can be calculated
using output of modal accelerometers instrumented throughout your structure.
Figure 43 provides some performance specifications of one of PCB Piezotronics’ impact
hammers that cost $760. The Modal Shop (owned by PCB) also offers a variety of impact
hammers which can be purchased or rented.
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