Moment in Ansys wb

[Badri07]

Hi All,
i am bit confused with applying moment in a solid model with 3D solid elements.i am using ansyswb,i read that solid elements like(solid 186) doesn't have rotational deg of freedom,so i am trying to apply force at a distance.is this right way of approach?

if the above statement is true,then moment icon in ansyswb can be only used to apply moment on the shell and beam elements is that right?

Thanks
Regards
Badri07

 

[cbrn]

Hi,
no, it is a "macro launcher" which internally turns out to apply a moment on a pilot node connected to the "scope" via MPCs. This can be done whatever the dimensionality of the elements involved.
As you have already thought, an equivalent method is to apply a force at a distance. However, internally WB will do exactly the same thing: apply the force to a pilot node connected to the "scope" via MPCs.
Why is it behaving like that and not in an easier manner? Because, in this way, just varying the type of MPCs will allow to vary the way in which the force / moment is transfered ("rigidly" or not).
Regards

 

[Badri07]

Hi Cbrn,
Thank you for your post,yes i just looked at the ansys wb output file and it looks to be consistent with what you are saying.
so,can i take it as applying force at a distance is the best way to replicate a moment,and the same method can be applied to any element mesh.

Thanks
Regards
Badri07

 

[cbrn]

Hi,
well... "the best way": no, I don't think so. If and when you have the opportunity to use it, and whenever you have input values expressed as torques, why make the effort to "decompose" the torque to a force at a distance? Things are different if you do have input values expressed as force+eccentricity.
Be careful: in some types of analyses, Ansys doesn't like very much the simultaneous presence of a force AND a torque on the SAME "scope" object, so the way out is... "force-at-a-distance" !

Regards