Applying temperature load to an element of a simple truss in static linear analysis.

[secluded1]

Greetings everyone,

I'm trying to solve a simple truss problem as can be seen in the following picture:

This is an orphan mesh. Vertical loads are applied at nodes 3 & 5 and also there is a temperature difference of 5 degrees on member 1 (the temperature of the member is increased 5 degrees).

When I define the material, I've also defined the expansion coefficient and left the reference temperature as zero.

The problem is that when I want to define a "Predefined Field" to assign the temperature of the member, I can only choose nodes when it asks me to choose the region for temperature definition. I can choose the elements just fine when the mesh is not an orphan mesh.
I think this prescribes the temperature at the nodes while I want the temperature to be prescribed for the element (constant along the element)

There is no node at the place of the intersection of the two slanted elements so I make two parts and merge them in the assembly module and that is when the orphan mesh is created.

Please let me know if you know the answer to any of the following questions:
1- Do you know any other ways to model the temperature loading for a truss structure?

2- Is there a way to avoid making an orphan mesh so that the "geometry" of my model won't be lost? (like maybe using a constraint instead of merging the instances)

3- How can I define the temperature field for an element of an orphan mesh?

Please let me know if any part of my question is unclear.
Thank you in advance

 

[Mustaine3]

Temperatures have to be defined at nodes (like BC).

You can tie nodes together. Or use equations. Interaction module > Constraint > Create
Or you try to merge the separate parts together to one part to get a common node. Assembly module > Instance > Merge/Cut

 

[secluded1]

Thank you mustaine3 for your prompt response.
I have already merged my parts and now have a single orphaned mesh (as shown in the question image).
Let's say in the triangular truss below, I want no temperature change in elements 1 & 2 but a constant temperature change of T for element 3:

Then, I will have a discontinuity of temperature at nodes 1 & 3 because they are connected to elements with different temperatures. Would this be a problem if I used constraints as you proposed? What would be the variation of temperature in element 1 if for instance I specify a temperature of 0 for node 1 and 10 for node 2?
Also, could you please explain further what you mean by "equations"?
Thanks again for the help. I'm really stuck on this.