ANSYS structural/thermal simulation
1. Introduction: The company I work for builds x-ray tubes for medical and security applications. Our x-ray tubes are typically a stainless steel housing (2-3mm wall thickness) with a 0.2mm x-ray window TIG-welded onto a cutout on the housing. In order to process these tubes, and achieve low internal vacuum pressures necessary for operation, they must undergo a heating cycle during active pumping. Experiments have been done in the past to investigate the stress and deformation of the x-ray window during the heating cycle. We have always wanted to develop a good simulation model to calculate the stress and deformation. This would allow us to apply our basic model assumptions during the development stage of the x-ray tube housing and window geometry.
2. Engineering Assumptions: I would like to look at an all stainless steel 304 rectangular housing (305mm (L) x 150mm (W) x 150mm (H), 3mm thick wall) with an internal pressure of 10E-6 Torr, external bakeout pressure (10E-3 Torr), undergoing a heating cycle (5 C/min ramp, 400C 12 hours soak, 20C/min cool). I'm interested in the stress and deformation of the 0.2mm thick stainless steel x-ray window (265mm (L) x 10mm (W)) during the bakeout.
3. Anticipated Results/Results verification: I have experimental data that demonstrates the x-ray window deflects along the centerline during the heating cycle. As a first run, I would like to quantify this deformation of the window with simulation. As a follow up project/work I may request parametric studies to show the optimal increased wall thickness to protect the window from deforming during the heating cycle. This will also give our company a chance to verify the elected freelance simulation expert for future work.
4. Timetable: This should be a relatively simple simulation to setup. I suggest using 2D-Axisymmetric elements. I need some quick results (by Aug. 7), with 2-4 ppt slides showing the model, boundary conditions, parameters, results.