Learning Forum

[Vanderbezi]

Hello everybody!

my aim is to model a 3-cylinder engine crankshaft with variable piston loads and with an initial rotational velocity of 5000 rpm.

As i am new to Ansys, i am not sure which type of analysis to use. I thought the transient structural analysis to be right, but for some reason within the "initial conditions" the rotational velocity is grayed out and i cannot use it.

should i change the analysis type? or am i doing something wrong with the rotational velocity?

regards,

Bezi

[Sandeep Medikonda]

Hi Bezi, 

According to the manual, you should be able to define Initial conditions in a Transient Structural Analysis. Please see this:

I checked this in 19.1, what version are you using?

Regards,

Sandeep

[Vanderbezi]

Hello,

I am using the 19.1 version.

My problem is, although the button for rotational velocity is there, it cannot be pressed, and only the normal velocity can be applied.

[Sandeep Medikonda]

Ahh, I see. I don't think this is possible from the GUI, but let me check if we can do this through a command object.

Regards,

Sandeep

[Sandeep Medikonda]

Hi Bezi,

  This can be done using the command snippet using the "icrotate" command snippet.

!   Commands inserted into this file will be executed just prior to the ANSYS SOLVE command.

!   These commands may supersede command settings set by Workbench.



!   Active UNIT system in Workbench when this object was created:  Metric (mm, t, N, s, mV, mA)

!   NOTE:  Any data that requires units (such as mass) is assumed to be in the consistent solver unit system.

!                See Solving Units in the help system for more information.



!arg1 - omega

!ar2-4 - (x,y,z) of the initial point of the vector in csys,0

!arg5-7 - (x,y,z) of the final point of the vector in csys,0



icrotate,all,arg1,arg2,agrg3,arg4,arg5,arg6,arg7,0,0,0,0

I tested this on a simple model and was able to successfully run this. I think this should be available from the GUI itself and will file an enhancement request on this. Thanks for bringing it to our attention.

P.S: If a post answers your original question, please mark it as a solution (‘As Solution&rsquo so that it might help someone in the future. This will help reduce repetitive questions and help provide better support on this Forum.

Regards,

Sandeep

[Vanderbezi]

thank you for your quick answer.

regards,

Bezi