recorders

jovo · Post by **jovo** » Fri Oct 29, 2010 11:40 am

Hello.
I m a student and I would like to ask about the results that come out from these two orders.Both of the output files contain 16 columns of results and they refer to a column that is separated by nodes in 4 elements that create the region 121. What is each of the column?-What do they mean?
I was said to use from section1 till section 6 and all the outputs contain 16 columns as well. Do they contain the same kind of results? What is the point of giving more than one section?

recorder Element -file C1,1_1st_columns_section1_deformation.txt -region 121 section 1 deformation

recorder Element -file C1,1_1st_columns_section1_forces.txt -region 121 section 1 force

Thank you very much for your answer!

vesna · Post by **vesna** » Fri Oct 29, 2010 12:27 pm

Is your model in 2D or in 3D?

jovo · Post by **jovo** » Fri Oct 29, 2010 1:50 pm

Dear Vesna
My model is 3D

vesna · Post by **vesna** » Sat Oct 30, 2010 11:58 am

When recording sectional forces (when in 3D) your output for one section can contain up to 6 columns of data in the following order: P, Mz, Vy, My, Vz, T, where z and y are local axis; P is axial force, M is the bending moment, V is the shear force and T is torsion. If you have used fiber section you will have P, Mz, and My for sure, and then if you aggregated shear or torsion to your section you can have other forces as well. In your case you have four forces in the section. From my explanation you should be able to figure out which one you have. Deformations of the section correspond to the section forces (e.g., axial force will be in the first column of the recorded forces, and thus axial strain will be in the first column of the recorded deformations).

When you record forces of several elements, in the output file you will first see the forces of the first element, then the forces of the second element, and so on...

jovo · Post by **jovo** » Sat Oct 30, 2010 1:11 pm

So, if I am right according to my model in which I use fibers and torsion as aggregator the repeated four columns will be P,Mz,My and T.What deformations do I get from M and T?What results do I get from the rest of the sections?(section2-section6).What are so many sections needed for?

Thank you very much for your answer!

vesna · Post by **vesna** » Mon Nov 01, 2010 9:53 am

I would recommend you to read any "Strength of Material" book to find out what deformations correspond to M and T.
You will get the same response quantities for the other sections as for section 1. Look at the OpenSees command manual to see the meaning of each argument in the element recorder command and you will understand it better.