Interfaces and Interphases

摘要: Several types of bonds may exist at the juncture between adjacent phases in contact. On microscale many composite materials, most desired is a perfect bond along sharp spatial boundary S vanishing thickness. It guarantees that both traction and displacement vectors remain continuous on S. Contact phase surfaces also involve presence one or more interphases, thin bonded layers additional homogeneous introduced, for example, as coatings particles fibers, products an interfacial chemical reaction. During composites manufacture and/or loading, interface expected to transmit certain tractions constituents. When resolved tensile shear stress reaches high magnitude, become imperfect by allowing partial complete decohesion, jump, possibly accompanied distribution ‘adhesive’ tractions. In opposite situation, compressive cause radial cracking contact, surrounding matrix. While magnitudes determine material propensity distributed damage, work required either decohesion must be provided release potential energy, which proportional volume Chap. 5. Therefore, small inhomogeneities are less likely sources damage than large ones.