Carbon Fiber prosthetic foot - STIFFNESS
Carbon Fiber prosthetic foot - STIFFNESS
(OP)
I have made a FEM model of a prosthetic foot. And i want to obtain the stiffness of the model.
I´m thinking of doing a Force vs Displacement graph, but i´m still not sure how to accomplish my purpose.
I need some help.
Thanks in advance.
I´m thinking of doing a Force vs Displacement graph, but i´m still not sure how to accomplish my purpose.
I need some help.
Thanks in advance.





RE: Carbon Fiber prosthetic foot - STIFFNESS
Of course nonlinear you will need to try several loads across the range of operating loads.
The one part that will be difficult/take some thinking is what do you want to consider to be the "stiffness" if are really looking for a single scalar value. Most structures will have a different stiffness depending on how they are loaded.
RE: Carbon Fiber prosthetic foot - STIFFNESS
To do this you can request displacement at a point in the model via the history output.
Then you can plot this by: visualization module -> create XY data -> plot. Now you get a displacement vs. time graph, where time is proportional to force.
When using a nonlinear analysis (Step -> nlgeom = on ) you can press "Save as" after plotting the XY data.
Then also save the load of interest in the same way.
Then you can combine the displacement-time and force-time plots by: Tools -> XY Data -> Create -> Source: operate on XY Data -> Combine(X,X) -> Select the two history outputs of interest and "Save as".
Then Tools -> XY data -> Plot