Initial settle¶
Ligaments may be overclosing other bodies by a large amount at the beginning of a simulation (due to the way that the ligament meshes are defined). Additionally, the ligaments may be assigned a prestrain where they will be carrying load at the start of the simulation. During pilot testing it was noticed that ligaments are more stable if there is an initial step where there are no active interactions between the ligaments and other surfaces.
The total time for this step is 0.01 seconds.
Interactions¶
There are no ligament interactions, and the other geometry is rigid and fixed, so there are no need to define interactions in this step.
Kinematic Boundary Conditions¶
Femur¶
The femur is fixed in all degrees of freedom throughout this step.
Tibia¶
The tibia is fixed in all degrees of freedom throughout this step.
Patella¶
The proximal nodes in the quadriceps tendon will be fixed in all degrees freedom in this step.
The patella is fixed in all degrees of freedom throughout this step.