[MBDyn-users] questions regarding to sky-engin.jp example 20
louis.gagnon at polimi.it
Mon May 29 09:37:58 CEST 2017
If you want to model a truck, you should start from the multibody model
I have made freely available in the examples section, look for
"semitrailer: 22 wheel vehicle model" on this page:
I recommend disabling the rigid ring (module-wheel4) tire model and
replacing it by a simple driver on the wheels until you better grasp the
functioning of MBDyn as it can be a difficult tire model to use.
On 27-May-2017 02:55 PM, Pierangelo Masarati wrote:
> On 05/25/2017 04:06 PM, onur akbas wrote:
>> Hi everyone,
>> I want to use mbdyn to model a truck. I started with the tutorials on
>> this site then found sky-engin.jp
> For issues about examples from sky-engin.jp you should definitely
> contact them.
>> and continued from there. By the way I'm using version 1.5.6.
>> At example 20:
>> 1) I did not understand what do revolute rotation joint and total pin
>> joints do.
> "revolute rotation" constrains rotation (and only that) about two
> axes. Nodes connected by a revolute rotation joint are only allowed
> relative rotation about a fixed axis (axis 3). Relative displacement
> is not constrained.
> "total pin joint" can constrain the absolute position and orientation
> of a node in a component-wise manner, that is you can specify
> component by component which are constrained and which are not.
> Moreover, for the constrained ones you can prescribe the
>> 2) I started to change it from 2d to 3d and got this error
>> ''Initial derivatives calculation 1 does not converge; aborting...
>> (hint: try playing with the ''derivatives coefficient'')''
> The model does not execute because two included files are missing.
> In general, to check whether such problem is critical or not, you
> should set a very large "derivatives" tolerance (greater than the
> error), to see if the analysis can continue past that. If it can, it
> will likely undergo an abrupt transient, but at least it tells you
> there's nothing blatantly wrong with your model.
> Sincerely, p.
>> The code is attached.
>> Thanks in advance
>> MBDyn-users mailing list
>> MBDyn-users at mbdyn.org
> Pierangelo Masarati
> Dipartimento di Scienze e Tecnologie Aerospaziali
> Politecnico di Milano
> MBDyn-users mailing list
> MBDyn-users at mbdyn.org
Louis Gagnon, Ph.D.
Dipartimento di Scienze e Tecnologie Aerospaziali
Politecnico di Milano
+39 02 2399 8642
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the MBDyn-users