This paper explores the capabilities within Thermal Desktop and Nastran to evaluate thermal stress and distortion in fabricated metal components subject to large temperature gradients. A comparison is made of the different construction methods and modeling techniques. Results are included on the time required for constructing, executing, and reporting on this type of analysis along with the author's suggestions for optimum use of time.
The presented analysis considers a pipe loop used to, thermally, condition a small cold plate. Different methods of attaching the pipe loop and different material combinations for the plate and pipe loop determine the thermal stresses and the plate distortion that will occur. The analysis includes different methods of Nastran and Thermal Desktop model construction, such as: A plate versus solid element NASTRAN model looks at stress and distortion in the pipe and “coarse’ and “fine” Thermal Desktop models examine the effect on displacement as a result of accuracy of thermal gradients.
Information is included on the time required constructing, executing, and reporting on this type of analysis along with the author's suggestions for optimum use of time.