Fractal Model of Contact Thermal Stiffness

The continuity, self-similarity, and self-affinity of a microscopic contact surface can be described by the Weierstrass–Mandelbrot (W–M) function in fractal theory. To address problems that existing normal load model does not take into account effect thermal stress is applicable to temperature variation joint giant magnetostrictive ultrasonic vibration systems, thermal–elastic–plastic established based on an extension traditional terms basic theory application scope, it takes effects difference, linear expansion coefficient, dimension, other parameters. Finally, difference at thermoelastic revealed through numerical simulations. results show nonlinearity stiffness mainly related roughness while change properties within certain range linear.