MECHENG 382 Lecture Notes - Ultimate Tensile Strength, Compressive Strength, Volume Fraction

• School: U of M
• Department: Mechanical Engineering
• Course: MECHENG 382
• Professor: All

Document Summary

Composites: combine two (or more) materials to enhance stiffness strength toughness (i) (ii) (iii, form of reinforcements: laminates (layers), long fibers, short fibers / whiskers, particles, role of interfaces between constituents is very important. Interface must be strong - for strain transfer: metal-matrix composites, polymer-matrix composites: stiff polymer fibers to epoxy matrix. Glass, ceramic, c or b fibers to epoxy matrix. Interface must be strong - for stress transfer: metal-matrix composites to increase strength above yield strength, polymer-matrix composites to increase strength. Density of composite: c = f f + 1 f. Stiffness of composites: random orientation of reinforcing phase may result in isotropic properties, a special class are fiber-reinforced composites (fibers along x, y and z directions) In general, composites are anistropic (see lecture 04) Lecture 35 - composites: these are known as orthotropic materials - 9 elastic constants, a further special case are fiber laminates in plane stress with fibers in x, y directions.