Damage zone development and failure sequence in glass fibre mat-reinforced polypropylene under static loading conditions
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The size of the damage zone in glass mat-reinforced PP (GMT—PP) can well be estimated by locating the acoustic emission (AE) events monitored during loading. It was shown that the extension of this zone can be adequately approximated by a circle of about 30-mm diameter, the half of which penetrates into the free ligament of the specimen.
Due to this very large damage zone, reliable mechanical properties can be determined only by using specimens with proper dimensions.
Analogies between the course of AE events as a function of the loading in different GMTs were attributed to an analogous mesh size of the reinforcing mat which characterizes its deformability. This seems to control the stress transfer and stress redistribution in the crack tip and controls the size of the damage zone.
KeywordsPolypropylene Loading Condition Acoustic Emission Mesh Size Glass Fibre
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- 1.L. A. Berglund and M. L. Ericson, “Glass mat-reinforced polypropylene. Ch. 3.6,” Polypropylene: Structure, Blends and Composites, J. Karger-Kocsis (ed.), Chapman and Hall, London (1994).Google Scholar
- 2.D. M. Bigg, “Manufacturing methods for long fibre reinforced polypropylene sheets and laminates,” Ch. 3.7 Polypropylene: Structure, Blends and Composites, J. Karger-Kocsis (ed.), Chapman and Hall, London (1994).Google Scholar
- 3.J. Karger-Kocsis, Q. Yuan, and T. Czigany, “Assignment of acoustic emission to the failure sequence and damage zone growth in glass fibre strand mat-reinforced structural nylon RIM composites,” Polymer Bull.,28, 717–723 (1992).Google Scholar
- 4.J. Karger-Kocsis and T. Czigany, “Fracture behavior of glass fibre mat-reinforced structural nylon RIM composites studied by microscopic and acoustic emission techniques,” J. Mater. Sci.,28, 2438–2448 (1993).Google Scholar
- 6.J. Karger-Kocsis, “Microstructural aspects of fracture in polypropylene and in its filled, chopped fibre and fibre mat reinforced composites. Ch. 3.4,” Polypropylene: Structure, Blends and Composites J. Karger-Kocsis (ed.), Chapman and Hall, London (1994).Google Scholar
- 6.J. Karger-Kocsis, “Instrumented impact testing of a glass swirl mat-reinforced reaction injection-molded polyamide block copolymer (NEC),” J. Appl. Polymer Sci.,45, 1595–1609 (1992).Google Scholar
- 7.J. Karger-Kocsis and Zs. Fejes-Kozma, “Failure mode and damage zone development in a GMT-PP by acoustic emission and thermography,” J. Reinf. Plast. Compos., Vol. 13 (1994).Google Scholar