Research on Damage Detection of Q235B Structural Steel Based on Non - collinear Mixing Nonlinear Ultrasonic Technology

Q235B carbon structural steel is a widely used structural material, and the ability to effectively detect its early damage directly affects engineering safety. However, most of the existing ultrasonic testing technologies focus on the research of conventional damage types and have significant deficiencies in detecting complex damage types.In this paper, low - carbon steel Q235B is taken as the research object. The mixing effect of components under complex damage states is analyzed through non - collinear mixing ultrasonic testing technology, and the influence law of each characterization target on the mixing nonlinear coefficient is explored.The research results show that: the nonlinear coefficient under the double nonlinearity of contact and material is smaller than that under material nonlinearity; the nonlinear effect first increases and then decreases with the increase of the stress field intensity; the nonlinear effect is most significant when the sampling direction is 90°, followed by 45°, and weakest at 0°.This research proves that the non - collinear mixing ultrasonic testing technology still has good detection effects under various complex working conditions, and provides an innovative quantitative analysis method for the damage detection of structural materials, which has important guiding significance for its engineering applications.