This paper considers the effect of tensile stress on the strength of the magnetic leakage field of a steel wire rope defect, which is easily neglected in the actual detection process. An inspection platform was built to load a variable force onto reproduced samples of typical defective wire ropes. Coil sensors were used to detect the radial component of the magnetic leakage field. In addition, the wavelet denoising method and wavelet singularity analysis were used to reduce the background noise and acquire the peak-to-peak values of low-frequency components of the magnetic flux leakage (MFL) signal, respectively. The validity of the extracted data and the effect of tensile stress on the strength of the magnetic leakage field were verified via the analysis of variance method. The experimental results reveal that the peak-to-peak values of the MFL signal from all the defective wire ropes increase with increasing tensile stress, in an approximately linear relationship. The tensile stress must remain consistent and stable during inspection to obtain better repeatability.Moreover, the detection accuracy can be improved by increasing the loading force within an appropriate range. The results of this study have significant implications for the enhancement of the reliability of wire rope defect detection.

High quality mesh is the basis of bone mechanics research and the precondition to ensure the accuracy of FEA (Finite Element Analysis) calculation. In order to obtain high accuracy and low distortion mesh of bone, the CFD (Computational Fluid Dynamics) meshing method is applied in this paper. The main process of bone finite element model construction consists of three parts, including CT (Computed Tomography) imaging, three-dimensional reverse modeling and meshing. By mesh optimization and boundary conditions imposition, the stress distribution of the occipital-atlantoaxial complex model and the relative motion angle between the Occipital Atlas and Atlantoaxial are obtained. According to the rotation angle checks, it is known that all the simulation results are within the range of cadaveric test data. The mesh generation technology provides a good idea and method for the study of bone mechanics.

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The type of disc brake has excellent efficiency and strong heat dissipation, which are beneficial to the transport capacity for mining motor vehicles. To ensure the reliability of the brake, the two-dimensional heat transfer differential equation model of disc brake is established, considering the dynamic change of convective heat transfer coefficient. The heat boundary conditions are established through the characteristics of brake disc structure and air condition, which is more accuracy than the traditional simplified method. Based on the PDE module in MATLAB, the mathematical model of heat transfer is solved and the transient temperature field is obtained. The calculation results are verified by the temperature field of the brake disc Link3900 NVH test platform. The results show that the research scheme has high computation accuracy, and can provide important basis, new ideas and advanced methods for the brake of mining motor vehicle in related fields.