topic Re: Torsional stress for a new defined section in Robot Structural Analysis Forum

Torsional stress for a new defined section

Anonymous — Thu, 08 Jan 2015 17:20:17 GMT

Robot gives a torsional moment for the new defined section, but it displays zero torsional stress !!

When I use a code section, it displays a torsional stress !!

Therefore the problem is in the section definition !!

I have defined my section, "C-Channel with inside return flange", and I have checked the torsional constant and all the boxes below it and calculate.

Then when I saved it, I choose a c-shape and specify its dimention.

Can you please tell me, what I have missed !!

Thanks for help.

Re: Torsional stress for a new defined section

Rafal.Gaweda — Fri, 09 Jan 2015 11:26:31 GMT

Wx is not calculated by Section Definiton module.
You have to calculate it by your own and update database Wx (TORS) field.

Re: Torsional stress for a new defined section

Anonymous — Fri, 09 Jan 2015 13:43:53 GMT

The same problem.

There is torque (N.m) but there is no torsional stress.

Please note that I have tried the following:

1) To use a UK standard section CEAB 60x5x0mm, and it has a wx = 0 in the section data base , but it gives a torsional stress. (How the torsional stress is calculated here for wx = zero !!)

2) To use a UK section SHSC 20x20x2mm, and it has a wx= 1060mm3 in the section data base, and it gives a torsional stress.

3) To use my new section and to give it wx value in the section data base and save the result. (The value of torsional stress is zero). !!! Stress = T / wx what is still missing ??

Thanks in advance for help.

Re: Torsional stress for a new defined section

Rafal.Gaweda — Fri, 09 Jan 2015 14:58:20 GMT

1) To use a UK standard section CEAB 60x5x0mm, and it has a wx = 0 in the section data base , but it gives a torsional stress. (How the torsional stress is calculated here for wx = zero !!)

Are you sure?

3) To use my new section and to give it wx value in the section data base and save the result. (The value of torsional stress is zero). !!! Stress = T / wx what is still missing ??

Have you reloaded section from database after change?

Re: Torsional stress for a new defined section

Anonymous — Fri, 09 Jan 2015 16:14:30 GMT

The Problem is solved now.

Thanks for help dear.