The objectives of this exercise are as follows:

Before applying time varying loads and boundary conditions, we need to define time dependent functions using the Field application. In this model, two time fields are defined, one for applied heat flux and one for volumetric heat generation.

Click on the Fields application. The Fields form will appear.

Similarly, a time dependent function for volumetric heating is defined as follows.

Our next task is to create a transient load case. Click on the Load Cases application. The Load Cases form will appear.

At this point, we will impose a transient flux load on the plate’s right edge. The magnitude of this flux load is 5000 W/m2 multiplied by the time dependent function flux_time defined earlier under the Fields application. Click on the Loads/BCs application.

Next, click on Select Application Region located on the Loads and Boundary Conditions form.

The volumetric heating can be applied in a similar way, using the Loads and Boundary Conditions form as follows.

Next, click on Select Application Region located on the Loads and Boundary Conditions form. We want to apply an internal heat generation inside a section of the plate from x=0.0 m to x=0.4 m. This application region will be selected by graphical cursor using the FEM geometry filter.

Now we are ready to set the analysis controls for transient thermal analysis. Click on the Analysis application. The Analysis form will appear.

For transient thermal analysis, we have to employ a starting temperature from which the solution evolves. If the initial temperature distribution is uniform, a default initial temperature is sufficient to specify the initial state. Otherwise, the Initial Temperature object in Loads and BCs application must be used to define initial nodal temperatures explicitly. See Initial Temperature, 75 for information.

We must now create a subcase. Click on Subcase Create located on the Analysis form. The Subcase Create form will appear.

Our last task on specifying analysis controls is to select the load case for the analysis. Click on Subcase Select located on the Analysis form. The Subcase Select form will appear.

To submit the job for MD Nastran thermal analysis, simply click on the Apply button on the Analysis form. It will take a while for the MD Nastran solver to perform a transient thermal analysis in the background.

When the analysis is completed, the model is ready for result processing.

We will create a contour plot of temperature distributions at time=700 sec using the Results Display form.

Now we will apply XY plotting to visualize the temperature-time history of Nodes 49 to 54.

At this point, we will modify the Y scale of the XY plot and display grid lines in the Y direction by clicking on the XY Plot application.

Next, you must click on Grid Lines located on the XY Plot form. The Grid Lines form will appear.