Fracture Mechanisms of a Thin Elastic Plastic Laminate

Document type: Conference Papers
Peer reviewed: Yes
Full text:
Author(s): Christina Bjerkén, Sharon Kao-Walter, Per Ståhle
Title: Fracture Mechanisms of a Thin Elastic Plastic Laminate
Conference name: ECF16
Year: 2006
Pagination: 647
City: Alexandroupolis
Organization: Blekinge Institute of Technology
Department: School of Engineering - Dept. of Mechanical Engineering (Sektionen för teknik – avd. för maskinteknik)
School of Engineering S- 371 79 Karlskrona, School of Engineering S- 371 79 Karlskrona
+46 455 38 50 00
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Language: English
Abstract: The fracture toughness of a polymer-metal laminate composite is obtained by mechanical testing of a specimen containing a pre-crack. The laminate is a material used for packaging. It consists of a thin aluminium foil and a polymer coating. A centre cracked panel test geometry is used. Each of the layers forming the laminate is also tested separately. The result is compared with the measured fracture strength of the individual layers. It is observed that the load carrying capacity increases dramatically for the laminate. At the strain when peak load is reached for the laminate only aluminium is expected to carry any substantial load because of the low stiffness of the LDPE. However, the strength of the laminate is almost twice the strength of the aluminium foil. The reason seems to be that the aluminium forces the polymer to absorb large quantities of energy at small nominal strain. The toughness compares well with the accumulated toughness of all involved layers. Possible fracture of the interface between the layers is discussed.
Subject: Mechanical Engineering\General
Mechanical Engineering\Structural Mechanics