Measurement of Air Layer Thickness under Multi-Angle Incidence Conditions Based on Ultrasonic Resonance Reflection Theory for Flange Fasteners

During the servicing of flange fasteners, sealing gasket and cover interface are prone to separation air contamination due factors such as stress, corrosion, vibration. In detection process, there two main issues: firstly, conventional ultrasonic measurement methods based on theory acoustic elasticity not applicable small thickness layer; secondly, use vertical incidence is difficult ensure influence actual structure. To address these issues, this paper first establishes a mathematical model resonance reflection, then calculates corresponding relationship between layer frequency under conditions. However, calculate different angles. meet requirements working conditions, finite element simulation further established. By comparing calculation results models incidence, reliability established verified. The reflection transmission pressure field distribution angles thicknesses simulated, function angle, thickness, first-order derived. This enables at any providing technical theoretical support for practical industrial applications.