Influence of bending parameters of waveguide on wall thickness reduction

This investigation established a finite element analysis model to determine the distribution of wall thickness in taper zones of 6063 waveguide bends with various radii, and demonstrated the relationship between wall thicknesses in the stable deformation zones and the bending radii. For the given waveguide with the chamber size of 15.8 mm in width, 7.9 mm in height and 1.0 mm in wall thickness, the distribution of outer wall thickness was calculated for a range of angles of bend at ρ=40 mm, and it was observed that the taper zone can extend to an angular range of 30° and greater. The calculated and empirical measured wall thickness values of 90° bends were compared, and apart from the 10° of abrupt tapering at either ends of the bend, the calculated rates of thickness reduction had errors of less than 2%. In addition, the arc-lengths of the neutral axes of the taper zones were also determined to be approximately 1.2 times the width B of the tube, and a formula to calculate wall thickness with angular correction was derived. Calculations also revealed that the mandrel support regions should coincide with the range of the taper zones, and that in the bends with small radii, the angular ranges could reach 30° or more. This report also analyzed other factors and their theoretical contributions to wall thickness variation, including the force exerted by the booster on the tube, coefficient of friction and mandrel support angle. These analytical calculations can provide a theoretical basis for the improvement of waveguide bends manufacturing process and research. © 2019, Editorial Office of Systems Engineering and Electronics. All right reserved.