## page was renamed from Static Models
== Passive Flexion ==

A predictive model of passive flexion of the knee to 45 degrees.  All materials and contact interactions are the same as described on the wiki frontpage.

=== Loads and Boundary Condtions ===

|| || Tibia || Femur ||
|| x || 0 || free ||
|| y || 0 || free ||
|| z || 0 || -100 N ramp t=0-1sec; constant t=1-2.5sec  ||
|| Rx || 0 || 0 deg t=0-1 sec; 45 deg t=1-2.5sec ||
|| Ry || 0 || free ||
|| Rz || 0 || free ||

=== Platform ===

Employed 8 threads on Ohio Supercomputing Center's Glenn cluster - 1 node; 2 quad core 64 bit AMD Opterons; Linux.

=== Results ===

The model converged with a solution wall clock time of '''32:44:25'''.  The equivalent model in dynamic analysis on 8 threads took '''10:17:39'''.  The static model took approximately 218% longer to solve.

==== Kinematic Comparison ====

The static and dynamic models exhibited essentially identical kinematics as seen in the following plots.

'''Flexion'''

{{attachment:flexion.png}}

'''Internal/External Rotation'''

{{attachment:ie.png}}

'''Varus/Valgus Rotation'''

{{attachment:vv.png}}

==== Stress/Strain Comparison ====

Likewise, stress, strain, and contact pressure distributions were also nearly identical.  A comparison of contour plots of the 3rd principal strain and contact pressure for the tibial cartilage are shown below.

''' Third Principal Green-Lagrange Strain (Pure Compression) '''

{{attachment:p3strain.png}}

''' Contact Pressure '''

{{attachment:cpress.png}}