The effect of the skin-core structure of injection-molded isotactic polypropylene on the stress distribution in bending tests

Authors

  • Rainer Glüge Institute of Mechanics, Otto von Guericke University Magdeburg
  • N. Mahmood Institute for Chemistry, Martin Luther University Halle-Wittenberg
  • I. Kolesov Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg
  • Holm Altenbach Institute of Mechanics, Otto von Guericke University Magdeburg
  • M. Beiner Institute for Chemistry, Martin Luther University Halle-Wittenberg
  • R. Androsch Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg

DOI:

https://doi.org/10.24352/UB.OVGU-2019-023

Keywords:

polypropylene, bending, skin-core gradient, microtoming, elastic-plastic

Abstract

We examine the effect of the skin-core structure of isotactic polypropylene (iPP) in bending tests. The depth-dependent material properties are determined in tensile tests and mapped to a finite element model. This enables the examination of internal stresses during bending numerically. In a bending test, one usually expects a monotonic stress distribution across the thickness, provided that the material is homogeneous and does not strain-soften. We found that the structural gradient of injection-molded iPP easily overcompensates the monotonic stress dependence, such that the maximal equivalent von Mises stress lies well below the surface in the so called shear layer. The latter is a result of the injection molding process.

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Published

2020-02-25

How to Cite

Glüge, R. (2020) “The effect of the skin-core structure of injection-molded isotactic polypropylene on the stress distribution in bending tests”, Technische Mechanik - European Journal of Engineering Mechanics, 39(3), pp. 252–260. doi: 10.24352/UB.OVGU-2019-023.

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