I am modeling a truss structure, in which elements have different temperatures. I don't want to use thermal analysis, because there are no heat flows or thermal changes. The analysis is static and the effect of temperature is just initial strain.
Mr. Nickpour,
I think this should be possible without doing a thermal analysis. Specify the temperature for each truss member as a "predefined condition" in the "step" category for your "initial" step. Choose "temperature" and select all elements in each truss one by one and set the temperature in them.
In material properties input your the coefficient of contraction and the reference temperature. Your reference temperature should that of the condition from which all trusses have changed, thus it is the initial temperature in calculating thermal strains for all members.
Now you should be able to simply run a general static or any other type of structural analysis with ABAQUS. The thermal strains will be calculated and implemented by ABAQUS in your analysis.
Mr. Nickpour,
I think this should be possible without doing a thermal analysis. Specify the temperature for each truss member as a "predefined condition" in the "step" category for your "initial" step. Choose "temperature" and select all elements in each truss one by one and set the temperature in them.
In material properties input your the coefficient of contraction and the reference temperature. Your reference temperature should that of the condition from which all trusses have changed, thus it is the initial temperature in calculating thermal strains for all members.
Now you should be able to simply run a general static or any other type of structural analysis with ABAQUS. The thermal strains will be calculated and implemented by ABAQUS in your analysis.
Hassan , I have a follow up question on that. I am running a non-linear implicit analysis for strength prediction for a composite joint. To include the effect of thermal residual stresses I have used predefined field in a step created before the load step. If I run it as a "General Static" step with NLGEOM on , I get very large unrealistic deformations. I have checked my CTE in my material model and they appear correct
technically, if you put an initial temperature. (not sure if it is in the property in the same section as density or in the load module as a predefined field), it will be considered as a termal load of the equivalent temperature. I tried it with composite shell long time ago, and it is how abaqus documentation prescribes it.
No termal analysis needed...just have to put temperature dépendent elastic/plastic/damage properties
Another alternative is to run the analysis as a coupled field of sequential type. First run the thermal analysis with the reference and applied temperatures. The Material properties should iclude both the structural and thermal. In the second analysis, read the results file and apply these temperatures as the boundary conditions. The structural loads such as force/pressure may be applied if any. Run the analysis and you will get the results. But before running the analysis, ensure that the element used has both the thermal and structural degrees of freedom.
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