Numerical investigation of swaging process characteristics of fabric braided power steering hose

The power steering hose in automotive power steering system is composed of a rubber hose and two metal fittings. The rubber hose is reinforced by fabric braided layers, while metal fittings are firmly clamped to both ends of rubber hose by the special swaging job. Since the main function of power steering hose is to circulate internal oil without oil leakage, the swaging process of metal fitting should be elaborately designed based on the profound investigation of process characteristics. However, owing to the complex micro structure of braided layers, the swaging process has been investigated either by time- and cost-consuming experiment or by the simple numerical analysis in which the braided layers are simplified as an isotropic solid. To overcome the demerit of experiment and to improve the accuracy of numerical method, an effective numerical analysis method by considering the anisotropy of braided layer is presented in this paper. The braided layers are modeled as an orthotropic solid and their equivalent material properties are derived by utilizing the homogenization method. Through the numerical experiments, the difference between the simple isotropic model and the current orthotropic one is compared, and the swaging process characteristics are investigated to the helix angle.