Construction Of 3-dimensional Geometric Model And Finite Element Analysis Of Mechanical Properties Of Braided Layers For Rubber Hose

Rubber hose has the characteristics of high compressive strength,small compressive deformation and acid-alkali resistance.It is often used to delivery or suck materials like various gases,liquids,viscous fluids and powder solid,and plays a key role in all works of life.Braided rubber hose(BRH)is one of the most commonly used rubber hose,especially in the automotive industry.BRH is composed of rubber layer and braided layer which bears the main load.The mechanical response and failure of BRH are determined by the mechanical properties of the braided layer.The mechanical properties of the braided layer are related not only to the mechanical properties of the material of braided layer,but also to the structure of braided layer.Therefore,it is necessary to study the relationship between the mechanical properties of the braided layer and the mechanical properties of the structure and material of braided layer.The relationship between the mechanical properties of braided layer and structure and mechanical properties of braided layer is established through the analysis of micro-mechanics of braided layer by finite element method.It has important guiding significance for the design and production of high-performance rubber hose,and the method is also applicable to the research on the mechanical properties of the skeleton layer of other rubber products(such as tires and belts).Content of the thesis are as follows:(1)The method of constructing 3-dimensional model of braided layer.Technological parameters of braided hose and dimensional parameters of fibers are the main concerns of the hose manufacturers.Through the analysis of the structure of the braided layer,the internal quantitative relationship between the geometrical structure of the braided layer,the size of fibers and the technological parameters is established,which lays the foundation for the 3-D model construction and mechanical analysis of the braided layer in the future.(2)The constraint conditions and boundary conditions of representative volume element(RVE)of braided layer.RVE is an effective model for studying equivalent mechanical properties of materials by means of micromechanics.In this paper,serrated RVE is taken as the research object of equivalent mechanical properties of braided layer.But the method of imposing boundary conditions on serrated RVE is rarely reported,so a method of boundary condition applied on the serrated RVE is explored,and constraint equation is analysis that should be satisfied when applying the boundary.(3)The method of mechanical properties of braided rubber hose.Taking the outer braided layer of brake hose as the research object,a 3-D model is built by using the model construction method of(1).Constraints and boundary conditions are applied,and the equivalent mechanical properties of the outer braided layer of brake hose are solved by simulation method.The validity of the constructing method of 3-D model,the creating method of constraint conditions and the imposing method of boundary conditions are verified by the axial tension experiment of braided layer.(4)A tool for rapid model construction and mechanical properties analysis of braided layer.The algorithm is developed on ABAQUS platform by using the Python,to realizes construction of 3-D model,the analysis of deformation,and the solution of equivalent mechanical properties.And graphical user interface plug-in is also developed.