scor0611
Bioengineer
- Dec 27, 2011
- 2
Dear friends,
I have trouble in setting parameters for hip replacement FEA. I'm interested in the femoral head and stem's neck joint. I have done several FEA and having trouble in interpreting the solution.
As we know, when the head was assembled to the stem, it was being hammered. My interests are the displacement of the head w.r.t to the neck after the impact.
Here's my questions:
1. say i hit the head 3 times during assembly and i want to modeled it using FEA. I applied 3 load steps with each same force but start at "0" N. Is there a way that ANSYS calculate 2nd load step based on the 1st load step's result? Just like we hammer a nail into the wall. After the first impact, the nail stick on the wall and the second impact start from the result of the first impact position.
2. Under solution -> contact tool -> sliding distance
I wonder what this sliding distance really mean? From my results, when i hammered it 5 times, the sliding distance of the contact region was 2.5 mm whereas the initial distance between the head and the end of the trunnion was 2.14 mm.
I think the sliding distance shouldn't pass 2.14 mm because if it is, the neck will overlapping the head. But, when i look at the animation and total deformation results, the neck didn't seem to overlapping the head as if the sliding distance is 2.5 mm. I also checked the penetration result, it was very very small.
Should i look at total deformation or sliding distance for a more accurate result?
Thanks heaps,
Willy
I have trouble in setting parameters for hip replacement FEA. I'm interested in the femoral head and stem's neck joint. I have done several FEA and having trouble in interpreting the solution.
As we know, when the head was assembled to the stem, it was being hammered. My interests are the displacement of the head w.r.t to the neck after the impact.
Here's my questions:
1. say i hit the head 3 times during assembly and i want to modeled it using FEA. I applied 3 load steps with each same force but start at "0" N. Is there a way that ANSYS calculate 2nd load step based on the 1st load step's result? Just like we hammer a nail into the wall. After the first impact, the nail stick on the wall and the second impact start from the result of the first impact position.
2. Under solution -> contact tool -> sliding distance
I wonder what this sliding distance really mean? From my results, when i hammered it 5 times, the sliding distance of the contact region was 2.5 mm whereas the initial distance between the head and the end of the trunnion was 2.14 mm.
I think the sliding distance shouldn't pass 2.14 mm because if it is, the neck will overlapping the head. But, when i look at the animation and total deformation results, the neck didn't seem to overlapping the head as if the sliding distance is 2.5 mm. I also checked the penetration result, it was very very small.
Should i look at total deformation or sliding distance for a more accurate result?
Thanks heaps,
Willy