Hi Joseph, please consider that there is no friction between the muscle and the wrapping surface. The wrapping only influences the level arm of the muscle force in respect to the center of rotation, i.e. the "effectiveness" of the muscle to produce a momentum. In addition, the wrapping and also affe...

Dear James

Thank you for your valuable hint. As a consequence, the issue does not exist anymore

Best regards

Gabor

Dear All I would like to run FD with prescribed motion for some of the DOF. Recently, the prescribed motion is defined within the .osim file, like this: <prescribed_function> <SimmSpline> <x> 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15</x> <y> 0 0.1 0.3 0.1 0 0 0 0 0 0 0 0 0 0 0 0 0 </y> </SimmSpline> </p...

Dear Tom, thank you for your hint. First I have to get familiar with programming to be able to understand it. Now, I use the ExpressionBasedPointToPointForce, acting on a 1 m long level arm. This approach is accurate enough for small angel range: <ExpressionBasedPointToPointForce name="FRICTION"> <b...

Dear All I am struggling to create a simulation of a pendulum with friction damping in the joint :( . I would like to apply a constant moment on the joint always acting against the rotational movement; like in the reality in case of a frictional (and not viscous) damper. Put it on another way: If th...

Dear Tom

Thank you very much for your useful hint!

Best regards

Gabor

Dear All In a simple pendulum model I would like to use the FunctionBasedBushingForce. My goal is to define the rotational resistance of a pendulum's joint in function of the rotational velocity of the joint. A BushingForce works well (see attachment), but the relationship between the angular veloci...

Dear James

With the help of the script proposed by you I was able to solve the problem!

Thank you very much!

Best regards

Gabor

Dear James Thank you for your reply. Yes, you understood my intention correctly. I assumed that I can run a Forward Dynamic with a prescribed movement for a particular DOF without scripting. For example, in Static Optimization we can simply link a motion file using the GUI of OpenSim. No scripting i...

Dear All I kindly ask you for help to solve the following problem. I built a simple pendulum model, consisting of the following 2 rigid bodies (see attachment "pendulum.osim"): - HEAD of the pendulum; visualized as a block - ARM of the pendulum, visualized as a sphere in the mass center of the ARM T...