Finite element analysis (FEA) of ultrahigh vacuum ConFlat-type flange joints for both Wheeler's and CERN's models were carried out. These models differ in the angle of inclination between the two shelves of knife-edge. The main value of this research is a computer simulation for deformable flanges and gaskets because all analyses before this have been done for absolutely rigid flanges (non-deformable flanges) and deformable gaskets. The analysis variable parameters are the radius of rounding at the tip of the knife-edge (0.05 … 0.2 mm), the angle between the shelves forming the knife-edge (70° and 90°) and the material properties of the copper ring (annealed and 1/4 hard). The calculation of bolted connections for tightening the flanges was also carried out as the experience has shown that during the tightening of bolts, they reach the yield point and begin to deform plastically. That leads to incomplete tightening of the flanges and, therefore incomplete sealing of the joint. The experimental research of the flanges tightening and the comparison with computer simulation results were carried out.

Computer simulation and experimental research of ultrahigh vacuum CF flange joints are widely used in accelerator and space technology have been carried out. The computer simulation was carried out in the automated software environment "ABAQUS", which allowed to study the stress-strain state in the sealing zone. The novelty of the work lies in taking into account the certified (real) hardening curve of the flange material during simulation since the work carried out before that was performed for an ideal rigid (nondeformable) flange, which introduces significant inaccuracies in calculations. Two of the most famous CF flange designs of Wheeler and CERN are simulated. Zones of distribution of intensity of stresses and strains, as well as components of the stress state are obtained. The experiments were carried out in four cycles of assembly and disassembly of the flange joint (with a change of the copper ring after each cycle) using standard flanges and gaskets. Also, to eliminate statistical inaccuracies, each experiment was carried out repeatedly to clarify all the measured parameters. A comparative analysis of the results of simulation and experiments is performed. The obtained data are close both qualitatively and quantitatively, which makes it possible to use them both for practical and research purposes.