SEDL / STP / STP772-EB / STP29376S

Crack Propagation Modes in Injection Molded Fiber Reinforced Thermoplastics

Mandell, JF
Massachusetts Institute of Technology, Cambridge, Mass.

Huang, DD
Massachusetts Institute of Technology, Cambridge, Mass.

McGarry, FJ
Massachusetts Institute of Technology, Cambridge, Mass.

Pages: 30    Published: Jan 1982

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Abstract

The modes of crack propagation are reported for injection molded short glass and carbon fiber reinforced thermoplastics. The matrices ranged from ductile to brittle, including Nylon 66, polycarbonate, polysulfone, poly(amide-imide), and polyphenylene sulfide; fiber contents were 30 or 40 percent by weight. The main crack is found to grow in a fiber avoidance mode, bypassing regions of agglomeration of locally aligned fibers. The local mode of crack tip advance varied with matrix ductility and bond strength. The fracture toughness and fatigue resistance of each material are related to the mode of crack growth.