I'm simulating an experiment in which a wood beam is submitted to thermal and structural loads at the same time. The beam is put in a furnace where tempeature rises according to ISO curve and at the same time, it is loaded with a constant force for the entire experimet's time.
I've manage to do part of my routine in ANSYS APDL. I'm using the PHISICS command, where I first record the thermal field and then, using the ETCHG command, I record the structural field. I apply the thermal load, which is transient, using the *DIM command. In the structural field, I'm able to import the thermal results using the LDREAD command. But I'm not being able to load my beam with the structural load (9 kN). What I need is, for example, in time=5 seconds, apply thermal load of 96 degrees Celsius and the 9kN load at beam center. Record the results of this step to enter in the next, then at time=10 second, apply 146 degrees Celsius and the 9kN load and so on.
Can anyone help me to find a way to do this? I'm attaching my code so you can get an idea of what I've done so far.
Can you tell me what element did you use for your analysis? Because I could not undrestand what method you used to solve this problem (load transfer or Multiphysics) from your explanation. Then, I will be able to suggest a solution.
Can you tell me what element did you use for your analysis? Because I could not undrestand what method you used to solve this problem (load transfer or Multiphysics) from your explanation. Then, I will be able to suggest a solution.
Hello, Hamidreza.
I'm using SOLID70 for thermal analysis and the command ETCHG,tts to switch to structural element SOLID185.
I attached the .txt file that I'm using as input in the question, if that helps.
It is a very interested question
I have some papers in simulation of thermal effect on prosthetic and orthotic structure,you can visit may home page
Presentation Hydrothermal Effect Study on the Amputee Comfort for the Abo...
Article Hygrothermal Effect on Mechanical and Fatigue Properties of ...
Article Experimental Study for Materials Prosthetic above Knee Socke...
Article Measuring The Thermal Conductivity of Difference Prosthetics...
Dear Ananda,
What I understood, you are trying to perform a "load transfer or solution transfer method" for a structural-thermal problem. Since your assumption is that the load on the beam is constant throughout the entire analysis and then temperature rises, performing a thermal analysis and transferring the solution to structural analysis for being considered as a boundary condition would not be appropriate. I gave it a try on both APDL and Workbench. However, the solution in your case is using SOLID226 or SOLID227(depends on using either hex or tet meh respectively) with the KEYOPT of 11. The constitutive equation that is working behind this element is created in such that you can perform a real structural-thermal Multiphysics analysis. This way, deformation and temperature will be calculated at the same time in each time step on all the nodes and you eliminate all difficulties associated with load transfer method. Ramp up the structural load first and keep the temperature at ambient in first step, then keep the load constant and rise the temperature in second step. This is the only approach that I can think of. Please recommend the answer if it worked for you.
Thank you, Hamidreza.
I'm going to try this approach, it seems to actually be more appropriate for my case.
Can you give me any tips on how to apply the mechanical load the way you said in your answer?
I did not get your question well. You are doing the experiment and really have a good idea how boundary conditions are going to be applied on the wooden beam. Or you are asking what APDL codes are needed for applying the BCs?? What I meant regarding ramp up was increasing the structure load gradually and then rise the temperature while the load remains the same. For that reason, you need to specify to time step which each of them can be divided into an explicit number of substeps. In first time step you consider that the load (which can be either force, displacement or pressure) is going to be increased from 0 to X and keep the temperature at room temperature (the first and second value should be ambient). You can divide this time step into let’s say 20 substeps. In second time step, remain the structure load at X and rise the temperature from ambient to whatever temperature you apply in the experiments. After you did the analysis you can extract temperature and deformation contour.
I asked about how to do it on ANSYS. The experiment was already done, I'm trying to recreate it numerically. I got what you explaned . I'm going to try to code that, I'm not very experient in ANSYS, so it's a bit hard for me yet. But thank you very much for your help.
It's a coupled problem.Chose element that is meant for both structural and thermal applications.First perform thermal analysis and then move carry forward the analysis by switching the element from thermal to structural.this option of switching can be done using GUI.Later you can apply structural load also.Give this a try and ask me for doubt if any.I suggest to use GUI in APDL.
- Badges
- Science topic