Scale Factor and Safety Factor in Hypermesh / Optistruct

Simon Frearson_21600

Hi,

I have question about safety factors. In the software HyperMesh/Optistruct, in the load collectors, when you select the Card Image LOADADD, you can apply a scale factor (real). This Scale Factor for me resembles a Safety Factor to me, as it multiplies the value of each load by the scale factor you choose to put.

By checking in the manual, I seem to see it does. But I am not entirely sure, because why wouldn't it just be called safety factor in that case? Or does it do something quite different which I have not fully grasped.

Much appreciated for whoever can answer me. I have attached relevant screenshots and links underneath.

 

https://2021.help.altair.com/2021/hwsolvers/os/topics/solvers/os/loadadd_bulk_r.htm?zoom_highlightsub=loadadd#loadadd_bulk_r__loadadd_bulk_r_fn_op1_bgz_31b

 

https://2021.help.altair.com/2021/hwdesktop/engsol/topics/SnRD/classic/tutorial/uc2_qualityfeel/load_add_creation.htm?zoom_highlightsub=loadadd

almeidaaap

Hi, Simon! I hope you are fine.

In this case, I see it as a scaling factor, you can evaluate the design in different load conditions just by changing the weights. 
I think like this:
"What is the response of my structure if I apply 10N at x and a 10Nm moment at z? What if I increase the moment to 15Nm?". More in the sense of normalising conditions and from there making scale factors.

On the other hand, the safety factor you will increase the value due to unpredictable conditions. I think like this:
"The estimated acting load is 10N, but as there may be unforeseen conditions, let's consider a FS of 1.5 and apply a load of 15N.

At the end of the day this will depend on your design considerations, if you would like to see the scale factor as a factor of safety, you can.

Cheers,

Arthur

Simon Frearson_21600

Arthur Penha_20544 said:

Hi, Simon! I hope you are fine.

In this case, I see it as a scaling factor, you can evaluate the design in different load conditions just by changing the weights. 
I think like this:
"What is the response of my structure if I apply 10N at x and a 10Nm moment at z? What if I increase the moment to 15Nm?". More in the sense of normalising conditions and from there making scale factors.

On the other hand, the safety factor you will increase the value due to unpredictable conditions. I think like this:
"The estimated acting load is 10N, but as there may be unforeseen conditions, let's consider a FS of 1.5 and apply a load of 15N.

At the end of the day this will depend on your design considerations, if you would like to see the scale factor as a factor of safety, you can.

Cheers,

Arthur

Splendid, I see. Many thanks. This is quite a neat tool to use in that case. In my general knowledge of Hypermesh, there wasn't any method to implement a chosen factor of safety, but as I can see it is possible via this approach.