# is it possible to output a design geometry using ansys?

Member

Hi,

I would like to create a flat torsional spring (flexible elements in between) with a fixed parameters as: outer diameter=85mm,inner diameter =10mm, torque applied on the spring = 100Nm and desired stiffness to be displayed by the spring as 280Nm/rad, material young's modulus 76Mpa. Thickness and the design space between these boundary conditions are variable.

I am new to Ansys and I would like to know if this software can be used in such a way so as to create a geometry from scratch that achieves this purpose. maybe topology optimization can be used for this but i am not sure what objectives and constraints can be used??

i have attached a photo of what i am trying to achieve. I will appreciate anyone who has some useful advice regarding this

• Member
edited October 17

You can build an ANSYS model to plot the length of the shaft vs the Reaction Torque.

In the description, the length of the shaft is called "thickness". A washer has a thickness and an OD and an ID.

Your problem says the target stiffness is 280 Nm/rad while the applied torque is 100 Nm. By simple division, you can compute the rotation of one end of the shaft is 100/280 radians = 20.463 degrees relative to the other fixed end.

You don't need ANSYS to solve this problem, you could do it with a hand calculation. Look up the equations for torsion on a shaft.

If you want to use ANSYS anyway, Open DesignModeler and draw a line along the X axis where the length of the line is marked as an input parameter. The line body is given a tube cross-section with the specified OD and ID. In a Static Structural model, a material is created with the Young's Modulus. One end of the line body has a fixed support. The other end has a remote displacement. In the remote displacement, you can set the Y and Z displacements to 0 and set the rotation about X to 20.462 degrees.

In Mechanical, under the Solution branch, insert a Probe, Reaction Moment and select the Remote Displacement. The reaction moment about X is marked as an output parameter. Under Analysis Settings, turn on Large Deflection.

In the Parametric set, provide a range of lengths on the rows of the Design Points Table. Click Update All Design Points. Ansys will go out and solve the model for each row of the table with the provided input length and fill in the output moment.

Plot that data. If your table doesn't have values of moment that cross 100, you will know if you need new rows that are longer or shorter lengths. Interpolate the length between the two values in the table that cross the 100 Nm value. That is the length that satisfies the requirements.

The video in this discussion shows the process.

Good luck!

• Member

You have the same question posted in two places. This one and the one in the link below.

The moderators don't like duplicate questions. I expect they will close one of the discussions.