How to apply thermal an mechanical load at the same time?

Submitted by JonathanSi on Sat, 08/02/2014 - 14:43

Hi guys,

I have some test results and now I need to model the test in ABAQUS to compare the model with the test results. The duration of the test was 30 minutes.
I have a simple single span girder with a mechanical and a thermal load at the same time.

The mechanical load is static and applies in the third points of the beam. From minute 1-15 the load is 2x60kN and from minute 15-30 the load is reduced to 2x15kN.

The thermal load is time-dependant and applies on the whole beam from all sides. The temperature curve is supposed to follow the standard curve form Eurocode (it looks like this: T= 20 + 345∙log10∙(8∙t+1))

So far I created two steps for the mechanical loads, but now I dont know how to apply the thermal load. Can anyone help me with that?
You can find my model on following link:
https://www.dropbox.com/sh/bjqje86nlsf3bv6/AABYqdd...

Cheers, and thank you very much for your help.
Jonathan

Frank Richter

Amplitude

Hello

you can define these loads in one single step using the command AMPLITUDE.

Beam elements do not have temperature as degree of freedom. But you can use *TEMPERATURE to specify temperature as a predefined field. See Verification manual
1.4.2 Beam stress/displacement elements
I. Load types: CENT, CENTRIF, GRAV, PX, PY, PZ, P1, P2, *TEMPERATURE, ROTA

Good luck

Frank

Sat, 08/02/2014 - 18:18 Permalink

JonathanSi

Hi Frank,

thanks a lot.

The way i have it right now:
1) Create a Predefined Field in the initial step with the ambient Temp. Constant 15 degree.
2) Create a static step with the Load (60kN)
3) Create a Coupled Temp Displacement step, where the heating starts. The heating is defined only by Interactions (radiation and convection) which are depending on the Amplitude I defined (Temp.Curve)
4) The fourth step is like the third with a different mechanical load.

I was hoping that this will work but unfortunatelly I get following error:
"in keyword *INITIALCONDITIONS, file "Test.inp", line 180311: Unknown part instance name 15

I am using CAE, nevertheless the .inp file looks like this:
"** Name: AmbTemp Type: Temperature
*Initial Conditions, type=TEMPERATURE
"Whole Beam-1"."Part - Whole Beam", 15., 15., 15., 15., 15., 15., 15., 15., 15., 15., 15."

Edit Predefined Field:
Distribution: Direct Specific
Section Variation: Constant through region
Magnitude: 15

I am using:

- homogeneous shell sections (should I use beam?)
- and as element types: Coupled Temperature-Displacement (S4RT)

Does anyone have an idea what wrong is in my model?
Thank you guys very much.

Jonathan

Mon, 09/01/2014 - 08:51 Permalink