Solution Time After Impact
This is a real period of time for which the program calculates the response
starting from the moment of the first impact. If you specify a drop height,
the solution time does not include the period of the free fall of the
body. The program estimates a value for the solution time based on the
model geometry and default material properties. The default solution time
is based on the time it takes the elastic wave generated by the impact
to travel through the model. The program estimates the velocity (Ve) of the elastic
wave from:
Ve=
(EX/r)1/2
Where EX is the modulus of elasticity and r
is the density. The wave starts propagating in the model at the moment
of impact. Assuming that the length of the model is L, the wave takes
a time period approximately equal to 2L/Ve
to travel to the farthest boundary, get reflected, and travel back to
the originating area. Forces that are opposite to gravity start acting
on the model during this period. The program sets the default solution
time to 3L/Ve.
Note that this is just an estimate that should help you enter a reasonable
period.
The impact period is usually very small. This is why the program asks
for it in microseconds. The maximum response may occur during impact or
after while the body is rebounding. The study can evaluate multiple impacts
and rebounds if you specify an adequate solution time.
The program gives a warning message if it
estimates that solving the problem will take more the 60 minutes.
Related Topics
Drop
Test - Contact
Drop
Test - Materials
Drop
Test - Result Options
Drop
Test - Setup
Drop
Test - Studies
Drop
Test - Viewing Results
Performing
Drop Test Analysis