how to applying Moment load?

[stressrise]

JHardy,

Thanks, yes that helps. I have pretty good deformation results and I am attempting some strain calcs. I have a simple shaft with two gears on it. I was wondering if I need to turn on all the rotational degrees of freedom. It is a solid and I made it a beam, which I did not do until I read this forum.

 

[ping]

JHardy,

Thanks for your recommend

Resently I haven’t more time to touch Pro/M, but fortunately I find the book of Adams & Askenazi.

I think words in P295- P300 of this book can solve my question which I asked in the forum before.

In P 296 of the book, there some words that mentioned the model used as the baseline in Fig.8.16(a) are ‘the model has no constrains, since the opposing loads place the pins and link in equilibrium. However, “soft” springs to ground are put in place at the mid-section of the link and at points on the pins to mathematically stabilize the analysis.’

Then I try to find the way to add this “soft” springs, but I can’t.

This do has been the question in my mind since you said in forum.

Could you tell me which function in Pro/M can add the “Idealizations” of spring to 3D or 2D models?! I only can add spring idealization to beam so far.

Additional, what is ‘Global RMS Stress’ which is appearing in Converge on area of ‘Static Analysis Definition’ window?

Thank you again!!

Ping

 

[JHardy]

Firstly, to add a “soft spring”, I suggest you go to “Idealizations | Springs”, and create a “Point to Ground” spring. You will need to create a ”Point” first, attached to a surface or edge at a suitable location, and then create a “Point to Ground” spring at this location, using suitable low stiffnesses to restrain the model. If your model is in equilibrium, there should be no (or at least negligible) deflection or load at the spring.



“Global RMS Stress” is a measure of the overall stress in the model – to quote from the on-line Help file:



Global RMS Stress Index

This is an estimate of the square root of the error in the total strain energy, which is the difference between the strain energy at the current pass and the exact strain energy, divided by the exact strain energy. To estimate the exact strain energy, the engine extrapolates the total strain energies of three successive passes.

The three successive passes are referred to as pass one, pass two, and pass three, with pass three being the most recent. The index may detect a significant error if the difference between pass three and pass two is not small compared to the difference between pass two and pass one. For multiple load sets, the value is the maximum over all load sets.



I suggest you browse through the on-line Help file – it sounds like there is a lot of stuff in there that might help you to get up to speed. On my system the on-line Help file is located at:



C:\Program Files\promech2001\html\usascii\promec\Rel23help.htm



I assume your location would be similar.



Hope this helps.

 

[Luis Aguirre]

Hello everyone,



I am new in the forum and maybe someone gave this workoround to the problem you were having ping. However, here are my two cents. As Jhardy explained to you solid element do not have rotational degree of freedom however the work around to this problem is apply the moment in the surface by using the option total force applied at a point under the distribution load option. The default for this option is usually total load. The way this option works is by distributing the load at the surface as a traction load instead of the moment. You must create or pick up a reference point on the surface that you will be applying the load. I have used this technique previously and work just fine.



I hope this information helps you!



Luis