A novel test fixture for mode III fracture characterization of monolithic laminates and composite sandwich specimens

Abstract

This work presents a novel test fixture for mode III fracture characterization of delaminations in monolithic laminates and face-core debonds in foam core composite sandwich specimens. The test fixture is configured as an extension of the already existing shear-torsion-bending (STB) test designed for monolithic laminates. The specimen sizing, lay-up configuration and the manufacturing process are presented. Accordingly, an overview of the test fixture is provided along with the data reduction method employed to compute the energy release rate. The results from representable fracture characterization tests are presented as force vs. displacement curves, where different definitions of the critical load for crack propagation can be defined. Thus, the critical value of the energy release rate is computed using analytically based equations for the different definitions given for the critical loads. The results show a stable crack growth for monolithic laminate specimens. However, a highly non-linear response of the sandwich specimens, before the onset of crack propagation, is observed. A non-linear numerical analysis and destructive specimen inspections are carried out in order to identify the source of the non-linear behaviour observed in the experimental results.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jun 29, 2021
Source ID
10.1177/00219983211020107

Entities

People

  • Brian Nyvang Legarth
  • Christian Berggreen
  • Lujin Lin
  • Pietro Sabbadin

Organizations

  • Office of Naval Research Global

Tags

Fields of Study

  • Materials science

Readers

  • Structural Health Monitoring of Composite Structures.