I am still try to track “my” BikeModel with measure dates.
My big problem is, my model is always statically/ kinematically
indeterminate. There are more reactions then rigid body degrees of
freedom! That happens, because I added some additional constrains
(AnyKinEqInterPolDriver) to the “original” model.
I tried to reduce constrains by applying cylindrical on place of
revolute joints, so I could save one constrain in z- direction each.
But there are unfortunately some forces in z- direction, so this is
not a good solution!
But I recognised that your model from repository has some reaction
forces ( 3. List of reaction forces) which are not active, e.g.
….CrankRotation.Reaction(0 active of 1 reaction)!!
Why does the driver still work?
Are there some additional tricks, which I should know?
Or do you have an advise how I could solve my statically/
kinematically indeterminate problem?
— In anyscript@yahoogroups.com, “jrgleemann” <lee5@b…> wrote:
>
> Hi John
>
> I am still try to track “my” BikeModel with measure dates.
>
> My big problem is, my model is always statically/ kinematically
> indeterminate. There are more reactions then rigid body degrees of
> freedom! That happens, because I added some additional constrains
> (AnyKinEqInterPolDriver) to the “original” model.
When you add a driver to the model it will by default carry the load
of the DOF’s of the particular driver. To avoid this the you should
type
Reaction.Type={0};
inside the driver definition
by default it will have the following setting
Reaction.Type={1};
which means the driver will carry the load, it’s an engine
> I tried to reduce constrains by applying cylindrical on place of
> revolute joints, so I could save one constrain in z- direction each.
> But there are unfortunately some forces in z- direction, so this is
> not a good solution!
> But I recognised that your model from repository has some reaction
> forces ( 3. List of reaction forces) which are not active, e.g.
> ….CrankRotation.Reaction(0 active of 1 reaction)!!
> Why does the driver still work?
The crank rotation driver has a Reaction.Type={0} this is why it is
listed as not active. If the reaction.type of this driver had been
one it would take away the crank moment from the legs.
> Are there some additional tricks, which I should know?
> Or do you have an advise how I could solve my statically/
> kinematically indeterminate problem?
>
In general when you add more constraints to this model you should
remove the same quantity. I hope the Reaction.Type issue will do this
for you.
I hope this answers your questions, otherwise please feel free to ask
again.