NX 10 - using FEM deformation data 1

[dmaricic]

Hello everyone.

I work in manufacturing company in tool and fixture design department as the designer and we use NX10.
I had a task for making welding fixture for one part. This part has the drawing that requires the part to be flexed on one side during welding to counteract the weight imposed on that part later in assembly, but this part is modeled in normal state, not flexed. When weigh is applied part goes to "normal" state.

My idea was to make a FEM analysis to see deformation of that part when weight is applied and then to use this "deformed" part to make a welding fixture because it has all kinds of brackets that needs to be in correct places.
This part is box-like shape, 2000x1000x500 dimensions and made from sheet metal ranging from 1-3 mm so the part is in elastic deformation when weight is applied.

Usually we don't have this kind of cases and we get 3D models as they needed to be.

Has anyone had some experience whit something similar? Has anybody used FEM deformation data and export it as separate part? Is it possible in NX?

Thanks in advance.

 

[dmaricic]

Hello again, maybe i was not fully clear in my explanation, i found a video how to do this in ANSYS.

https://youtu.be/gTaBke4LDD0

 

[Toost]

It is fully possible.
The difficult step is to transfer the info from the FEM result to the model because the output from the FEM is so completely different to what you expect to input into to your model.
For example you have entered length, width and thickness for your sheet metal, but the FEM output will be how much a couple of hundred points on that surface has moved. And your model has no such parameters.
If is a one time job, you can take a few measurements from the deformed shape and use as input to deform the model using specific deformation features.
If it is a frequent job, you should try develop some kind of semi automated process for this.

I know one company manufacturing parts for jet-engines. The turbine blades work in a very high temperature and under bending stress but are manufactured in cold state and without stress,
because of this, the blades must be manufactured in a shape that will deform to be aerodynamically correct when hot and stressed.
to accomplish this, they developed a automated process where the model was "heated and stressed" in a FEM system, then the result was compared to the aerodynamically optimized shape, and if there was deviations the model was changed and the loop re-executed.

In NX you can deform models using the "Global shaping" or "Global Deformation" tools.

Regards,
Tomas