Research on ultrasonic testing method for tangential contact stress based on equivalent medium theory

Area of Science:

• Mechanical Engineering
• Materials Science
• Non-destructive Testing

Background:

• Machine tool joint surfaces are critical for stiffness and accuracy.
• Quantifying contact stress distribution is essential for understanding joint behavior.
• Existing methods may lack precision for low-stress applications.

Purpose of the Study:

• To propose and validate an ultrasonic testing method for tangential contact stress.
• To establish a relationship between ultrasonic wave propagation and contact stress.
• To support accurate characterization of machine tool joint surfaces.

Main Methods:

• Developed a virtual material model of rough contact interfaces using fractal theory.
• Derived equivalent material parameters for ultrasonic critical refracted longitudinal waves under stress.
• Constructed an ultrasonic acoustic time difference model based on acoustic elasticity.
• Established a critical refractive detection model for tangential contact stress using equivalent medium theory.
• Performed experimental measurements and simulations.

Main Results:

• Successfully measured tangential contact stress on experimental specimens.
• Generated shear stress distribution cloud maps of contact surfaces.
• Validated the accuracy of the proposed method through theory, simulation, and experiments.
• Demonstrated the method's effectiveness for low-stress assemblies.

Conclusions:

• The proposed tangential contact stress ultrasonic testing method provides reliable data for characterizing joint surface contact states.
• This technique enhances the understanding of mechanical properties in joint surface connections.
• The method is significant for improving the performance of low-stress machine tool assemblies.