You are here
Slope of Contact force Vs time curve too steep.
Thu, 2010-10-21 00:36 - priyadd84
Dear all,
I did a 3 pt bending impact simulation with an elasto plastic model. But the slope of contact force vs time curve is too steep at the beginning of the impact. One trivial way of reducing the slope is by reducing the young's modulus of elements in the vicinity of contact or the impactor. Also reducing the mass of the impactor and the impact velocity did not help in reducing the slope.
Is there any other non-trivial parameters that controls the slope of contact force vs time plot? Thanks ina dvance.
»
- priyadd84's blog
- Log in or register to post comments
- 5141 reads
Comments
Did you do your own impact
Did you do your own impact test, or are you comparing your model to a F-t curve from the literature? If you did your own experiment, you might want to investigate what filtering / signal conditioning was performed on the raw force signal from the load cell. After being processed by the filters and conditioners, the rise time of an impactor force might very well have been increased artifically.
Hello, most explicit
Hello,
most explicit codes use some kind of contact stiffness to control penetration. You should find it where, and try around, but beware of penetration problems.
Also some slight changes in geometry can help. Usually if only one pair of nodes come into contact for the first time, than only these nodes carry the whole kinetic energy of the system. This may lead to huge amplitude vibrations in your curves (particularly if your impactor is rigid). It is better if more nodes come into conact, or at least nodes of the impactor are not directly above the nodes of your beam.
Andras