Of Long Fiber Mmc Micro-mechanics Model And Performance Evaluation

The metal metrix composite is a kind of material of many phases, including base, phase of increasing strength or tenacity, phase of interface and etc. Its property, damnification and devastation law, fracture and failure mechanism, flowing deformation process of plasticity are depending on its quality of composition material, and its microstructure characteristics. These characteristics are the volume portion of phase of increasing strength, the law of distribution, the shape, the quality of interface phase and etc. As a result, it is necessary to set up micromechanics model of MMC, thus to establish the quantitative relationship between macroprop-erty of MMC and its composition material or microstructure, disclosing the inner mechanism of different material combination determining different macroproperty.The micromechanics model of MMC can be extracted into five models: straton model, continuous identical axis model of cylinder, turning shape model, externally square and internally circular model, externally circular and internally square model, limited component model. As far as elastic and unelastic qualities are concerned, compound materials are non-well-distributed in nature. Therefore, the stress distribution is uneven in MMC if this kind of compound material is exerted by external load. This sort of uneven distribution determines the behavior of materials, and can be used to explain the superior property of compound material in contrast to traditional material. Based on some simplified hypothesis, five models which are applied as a foundation to analyse and study the more sophisticated continuous fibers MMC have been summarized and constructed in this article. And, aiming at these five basic mechanics models, quantitative calculation is in progress, so the mechanics properties such as axial direction stiffness, lateral direction stiffness , shearing strain modulus, closing proportion modulus etc. have been worked out. Because there are both differences and unities among the five mechanics models and since these models are basic unit models which compose real compound material , the quantitative solutions of properties of the five models can be organically integrated and reasonably accepted or rejected, when calculating efficacious constants and properties of actual continuous fibers MMC. The continuous fibers MMC usually manifest unsymmetry while being drawed and compressed, phase of increasing strength often maintain elastic condition when being exerted some loads,so it is very important to study the flowing deformation mechanism of molding property of base body. There are two large kind of factors which can control the plastical deformation of base; factors which influence the stress state of base; factors which give rise to transformation of microorganization and then cause the flowing deformation qualities of base to alter as a result of intermingling with composition of increasing strength. As far as continuous fibers MMC is concerned, developing velocity of inner stress and the microstructure of base dominate its macrorela-tionship between stress and strain together. The behavior of axial direction stress or strain could be divided into three stages: the first period, elastic base and elastic fibers; the second period, plasticity base and elastic fibers; the third period, plasticity base and plasticity fibers or fracturing fibers. The average elastic strain of the two phases both equal the strain of the compound material during the first period. During the second period, the sum of the elastic and molding property strain of base equals the strain of MMC. And the sum above also equals the malcooperation without stress between base and continuous fibers, only their marks being adverse to each other. But the plastical strain of compound material is by far weaker than that of base because of the restraining effects. This means that the stress and strain have been coordinated by stress equilibrium from the beginning to the end on the condition of unload. The work hardening rate of original posit...