The Influence of Random Filament Packing on the Elastic Properties of Composite Materials.

摘要: Abstract : A new method of micromechanical analysis composite materials (such as boron- or glass-fiber-reinforced aluminum epoxy) that takes account the randomness arrangement reinforcing filaments. Previous analyses assumed a regular geometric array, in which case physically unrealistic square array showed surprising agreement with experimental data. Since available computers cannot handle completely random arrangement, basic pattern was generated by random-number techniques and then reflected to obtain symmetry; this unit repeat itself throughout material. Solutions for modulus elasticity were obtained 10-by-10 each 20 geometries using constituent stiffness ratios corresponding boron/aluminum, glass/epoxy, boron/epoxy composites, filament volume contents 39, 55, 70 percent. The symmetry permitted use standard boundary/value solution methods. When packing is randomized, more realistic 'hexagonal array' better data than 'square array.' latter results much higher local stress concentrations, model could lead unduly conservative analyses. (Author)