HuntCrossleyForce Sphere/HalfSpace
Posted: Tue Nov 07, 2017 2:29 pm
Hello,
I am playing around with the Hunt Crossley model in Simbody.
I am trying to understand what would be the value of s1 in the following equation:
(see https://github.com/simbody/simbody/blob ... e.cpp#L115)
when there is a contact between a sphere and a half space. For instance, I define a HuntCrossleyForce in an OpenSim xml in this way:
where plate is a ContactHalfSpace and r_foot_lat_heel is a ContactSphere. I guess it would make sense if s1 was 1 but it would be nice if someone could confirm or explain.
Thanks!
I am playing around with the Hunt Crossley model in Simbody.
I am trying to understand what would be the value of s1 in the following equation:
Code: Select all
const Real s1 = param2.stiffness/(param1.stiffness+param2.stiffness);
when there is a contact between a sphere and a half space. For instance, I define a HuntCrossleyForce in an OpenSim xml in this way:
Code: Select all
<HuntCrossleyForce::ContactParametersSet name="contact_parameters">
<objects>
<HuntCrossleyForce::ContactParameters>
<!--Names of geometry objects affected by these parameters.-->
<geometry>plate r_foot_lat_heel</geometry>
<stiffness>3777162</stiffness>
<dissipation>2</dissipation>
<static_friction>0.8</static_friction>
<dynamic_friction>0.8</dynamic_friction>
<viscous_friction>0.5</viscous_friction>
</HuntCrossleyForce::ContactParameters>
</objects>
<groups />
</HuntCrossleyForce::ContactParametersSet>
<!--Slip velocity (creep) at which peak static friction occurs.-->
<transition_velocity>0.1</transition_velocity>
Thanks!