Mechanical Analysis Of Mesh Woven Structure

The problem of interference existing in high-power passive microwave components and antennas, seriously affects the design, stability and normal work of satellite communications system. Mesh reflector antenna is one of the key devices in mobile communications, electronic surveillance, data relay and microwave remote sensing satellites. However, the metal mesh, a kind of mesh structure for reflecting and receiving signal is the key nonlinear component causing interference. The wave interference is caused by the inherent nonlinearity of mesh reflector surface, and the nonlinearity includes contact and material nonlinearity. The contact nonlinearity in metal mesh structure is inevitable, which is the main cause of the interference problem. The study found that the contact forces of different contact knots of wire mesh directly determine the contact nonlinearity. Therefore, the mechanical analysis of mesh reflector surface, to obtain the contact forces, is of great significance. Furthermore, the mechanical analysis of mesh reflector surface provides the accurate model of the mesh reflector surface, and lays the foundation of the later analysis.The mechanical analysis of wire mesh is difficult because of the complicated structure and the nonlinear size effect. This thesis studies a method based on fractal geometry for analyzing the mechanical properties of wire mesh.1. The elastic properties of small scale wire mesh have been studied. Firstly, the mechanical model of wire mesh is established, and its mechanical properties are analyzed by simulation. Thus, the orthotropic property of wire mesh can be proved. Secondly, the mechanical equivalent method is searched by simulation analysis and the finite element method, and the mechanical properties of wire mesh structure can be described by the orthotropic plane stress structure. Finally, the elastic parameters of small scale wire mesh can be acquired by the established mathematical model.2. The fractal mechanics of wire mesh structure has been discussed. The fractal characteristics of wire mesh structure are revealed and its slit island dimension and box counting dimension are calculated. The map relationship between generalized Sierpinski carpet and wire mesh structure is established, therefore the elastic parameters of large scale can be predicted based on small scale wire mesh structure. The feasibility of this method is demonstrated by a numerical example in this thesis.3. The statistical distribution of the contact force at specified area of the mesh reflector is studied by statistical method. What’s more, a kind of software to analysis the contact force of wire mesh is developed.