Search found 77 matches
- Thu Feb 17, 2022 9:37 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: Generation 1 Cut Planes
- Replies: 2
- Views: 1113
Re: Generation 1 Cut Planes
They are aligned with MRI axis and field of view.
- Sun Feb 14, 2021 7:02 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: Kinematics data channel name conventions
- Replies: 4
- Views: 1399
Re: Kinematics data channel name conventions
Dear Kostas, First of all, each kinematics-kinetics data folder should have a state file (within the zipped vproj file as I recall) that has all the coordinate system transformations, e.g. between anatomical, optimized, tibia, femur, robot, optotrak, etc. That state file corresponds to that motion, ...
- Fri Jan 22, 2021 5:44 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: Kinematics data channel name conventions
- Replies: 4
- Views: 1399
Re: Kinematics data channel name conventions
Dear Kostas, During experimentation of the tibiofemoral joint, the tibia was indeed fixed. Yet, the reporting of joint kinematics is for posterior translation of tibia. See https://simtk.org/plugins/moinmoin/openknee/Infrastructure/ExperimentationMechanics?action=AttachFile&do=get&target=Knee+Coordi...
- Tue Dec 15, 2020 6:49 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: The Question about Pre-strain
- Replies: 24
- Views: 6758
Re: The Question about Pre-strain
I did try that, however, in 2.5 files 'fiber' is seen as a synonym for 'mat_axis'. In 3.0 files this is no longer the case. When loading it into FEBio Studio (3.0 files) it shifts into the MRTI part. We are currently using FEBio version 2.9. We also create our models in a scripted fashion, without ...
- Mon Dec 14, 2020 6:26 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: The Question about Pre-strain
- Replies: 24
- Views: 6758
Re: The Question about Pre-strain
Dear Marloes, Did you try by defining fiber direction outside the elastic material definition? As <material id="11" name="acl" type="uncoupled prestrain elastic"> <density>1.5e-09</density> <k>73.2</k> <elastic type="trans iso Mooney-Rivlin"> <c1>1.95</c1> <c2>0</c2> <c3>0.0139</c3> <c4>116.22</c4> ...
- Thu Aug 13, 2020 9:41 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: Can user submit their model on 'simulations' platform?
- Replies: 1
- Views: 976
Re: Can user submit their model on 'simulations' platform?
Simulation feature was a test implementation to be able to run a simple femur-ACL-tibia model at user-desired kinematics boundary conditions. The feature does not permit users to submit their own models. I recommend you to download FEBio (https://febio.org/) on your computer to run simulations with ...
- Tue Dec 17, 2019 8:15 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: Ligament bending
- Replies: 3
- Views: 1440
Re: Ligament bending
The bending that you see is expected as the ligaments have a ground substance with a small but stabilizing modulus (providing compression and bending stiffness). You can set that ground substance to zero to represent a purely tension only ligament material. Yet, the simulation will likely have conve...
- Tue Oct 22, 2019 7:54 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: File not opening.
- Replies: 1
- Views: 1138
Re: File not opening.
Dear Prasanna, .NII format is for storing images, e.g. MRIs of the knee. They are NOT model files. Open Knee(s) - Generation 1 has meshes as .inp files that can be imported to Abaqus. Nonetheless, all our model files for Generation 1 and Generation 2 (see wiki page "Roadmap") are in FEBio format (.f...
- Tue Oct 22, 2019 7:50 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: Ligament bending
- Replies: 3
- Views: 1440
Re: Ligament bending
Hi Sebastian,
Can you clarify what you mean by unphysiological bending of LCL and MCL? Are they penetrating the bone surface? If so, this can be resolved by activating contact between these ligaments and bones.
Ahmet
Can you clarify what you mean by unphysiological bending of LCL and MCL? Are they penetrating the bone surface? If so, this can be resolved by activating contact between these ligaments and bones.
Ahmet
- Mon Oct 22, 2018 5:24 am
- Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
- Topic: Knee extension of the model including patella
- Replies: 2
- Views: 1424
Re: Knee extension of the model including patella
Dear Lefteris, oks001 is NOT the specimen modeled in Open Knee(s) - Generation 1, which is in tf_joint_FEBio_v2.feb. You can get the geometries for Open Knee(s) - Generation 1 in the source code repository, specifically at https://simtk.org/svn/openknee/_gen1/dat/geo/version2geo/ Please note that wh...