Drop Test- Dropping a Sphere onto a Flexible Plate 2

[jdesouza]

I'm trying to simulate a steel sphere falling from a specified height and landing on a plastic rectangle so see the stresses on the rectangle.

Can this type of analysis be done with the Drop Test mode? Or are we limited to dropping a part or assembly onto a planar "floor"?

Any feedback would be helpful.

~Jeff~

SolidWorks 2006 SP3.1 on WinXP SP2
Pentium(R)4 CPU 3.60GHz 1.00GB of RAM

 

[NickE]

From what I was just reading, the floor in drop test is infinately stiff, and has no damping properties.

Design News (04.04.05) pg. 68 <--- Note how old the issue is though. (They also said that that was supposed to be fixed in the next release.)

 

[jdesouza]

The floor in SW 2006 can have dampening/elastic properties, which is a nice addition.
My problem is that I'm trying to analyze a piece of plactic (specifically, it's a cover to a housing) and it must be able to withstand a certain mass in the shape of a sphere being dropped from a certain height. This is a UL requirement.
I cannot just use the floor to simulate the cover because I need to add ribs and optimize thickness until the part can withstand the impact.


~Jeff~

SolidWorks 2006 SP3.1 on WinXP SP2
Pentium(R)4 CPU 3.60GHz 1.00GB of RAM

 

[kellnerp]

You probably want to use Cosmos/M for this.

http://www.engtran.com

http://www.niswug.org

 

[Jabberwocky]

I don't know how precise you need to be, but couldn't you use a point load to represent the force of the sphere? Alternately create a split line circle to give more area than a single point?

 

[jdesouza]

I spoke to a Cosmos expert who works for Solidworks on wednesday at a seminar and he said that this type of analysis cannot be done w/ Cosmos linear analysis but it is being considered for a future release.

I found it very interesting that you can simulate a crate full of bottles dropping onto a floor and the kinematics of the crate and bottles are simulated very accurately, but the program wouldn't be able to handle dropping a bottle onto a stationary crate! It would seem that the latter example would be considerably more simple to simulate.

I wonder if I could fool the program into doing what I need it to do. What if I dropped the plastic plate and the ball simultaneously, but set the height of the ball such that the plate has time to hit the floor and come to rest before the ball hits. It wouldn't be an ideal model because the plate would not be fixed upon the ball's impact and thus be able to bounce back up, but it's better than nothing!

~Jeff~

SolidWorks 2006 SP3.1 on WinXP SP2
Pentium(R)4 CPU 3.60GHz 1.00GB of RAM