A modified DCB-UBM test method for interfacial fracture toughness characterization of sandwich composites

Christian Berggreen*, Vishnu Saseendran, Leif A. Carlsson

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

A novel double cantilever beam test method for interface fracture toughness characterization of debonded sandwich composites is introduced. The method is called DCB-UBM (Double Cantilever Beam loaded with Uneven Bending Moments), where pure moments are applied to the beams at the crack end using torsional actuators, to generate crack propagation along the face sheet/core interface. A data reduction method is proposed to determine the fracture toughness. Fracture testing is performed on a typical marine grade sandwich configuration consisting of PVC H45 foam core and glass fiber face sheets to demonstrate the applicability of the test method. The obtained fracture toughness agrees with interface toughness values in the literature measured using other test methods with the same material system. The effective kinematics of the test rig is measured using Digital Image Correlation (DIC) by studying the rotations and moments of a specially designed calibration specimen and comparing the results against finite element results. The DCB-UBM specimen and test method is a promising candidate for obtaining face sheet/core interface fracture toughnesses in sandwich composites.
Original languageEnglish
JournalEngineering Fracture Mechanics
Volume203
Pages (from-to)208-223
Number of pages16
ISSN0013-7944
DOIs
Publication statusPublished - 2018

Keywords

  • DCB-UBM
  • Sandwich composite
  • Mode-mixity
  • CSDE
  • Face sheet/core interface

Cite this

@article{e424d74532784564ab71534c76c0f747,
title = "A modified DCB-UBM test method for interfacial fracture toughness characterization of sandwich composites",
abstract = "A novel double cantilever beam test method for interface fracture toughness characterization of debonded sandwich composites is introduced. The method is called DCB-UBM (Double Cantilever Beam loaded with Uneven Bending Moments), where pure moments are applied to the beams at the crack end using torsional actuators, to generate crack propagation along the face sheet/core interface. A data reduction method is proposed to determine the fracture toughness. Fracture testing is performed on a typical marine grade sandwich configuration consisting of PVC H45 foam core and glass fiber face sheets to demonstrate the applicability of the test method. The obtained fracture toughness agrees with interface toughness values in the literature measured using other test methods with the same material system. The effective kinematics of the test rig is measured using Digital Image Correlation (DIC) by studying the rotations and moments of a specially designed calibration specimen and comparing the results against finite element results. The DCB-UBM specimen and test method is a promising candidate for obtaining face sheet/core interface fracture toughnesses in sandwich composites.",
keywords = "DCB-UBM, Sandwich composite, Mode-mixity, CSDE, Face sheet/core interface",
author = "Christian Berggreen and Vishnu Saseendran and Carlsson, {Leif A.}",
year = "2018",
doi = "10.1016/j.engfracmech.2018.06.036",
language = "English",
volume = "203",
pages = "208--223",
journal = "Engineering Fracture Mechanics",
issn = "0013-7944",
publisher = "Pergamon Press",

}

A modified DCB-UBM test method for interfacial fracture toughness characterization of sandwich composites. / Berggreen, Christian; Saseendran, Vishnu; Carlsson, Leif A.

In: Engineering Fracture Mechanics, Vol. 203, 2018, p. 208-223.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - A modified DCB-UBM test method for interfacial fracture toughness characterization of sandwich composites

AU - Berggreen, Christian

AU - Saseendran, Vishnu

AU - Carlsson, Leif A.

PY - 2018

Y1 - 2018

N2 - A novel double cantilever beam test method for interface fracture toughness characterization of debonded sandwich composites is introduced. The method is called DCB-UBM (Double Cantilever Beam loaded with Uneven Bending Moments), where pure moments are applied to the beams at the crack end using torsional actuators, to generate crack propagation along the face sheet/core interface. A data reduction method is proposed to determine the fracture toughness. Fracture testing is performed on a typical marine grade sandwich configuration consisting of PVC H45 foam core and glass fiber face sheets to demonstrate the applicability of the test method. The obtained fracture toughness agrees with interface toughness values in the literature measured using other test methods with the same material system. The effective kinematics of the test rig is measured using Digital Image Correlation (DIC) by studying the rotations and moments of a specially designed calibration specimen and comparing the results against finite element results. The DCB-UBM specimen and test method is a promising candidate for obtaining face sheet/core interface fracture toughnesses in sandwich composites.

AB - A novel double cantilever beam test method for interface fracture toughness characterization of debonded sandwich composites is introduced. The method is called DCB-UBM (Double Cantilever Beam loaded with Uneven Bending Moments), where pure moments are applied to the beams at the crack end using torsional actuators, to generate crack propagation along the face sheet/core interface. A data reduction method is proposed to determine the fracture toughness. Fracture testing is performed on a typical marine grade sandwich configuration consisting of PVC H45 foam core and glass fiber face sheets to demonstrate the applicability of the test method. The obtained fracture toughness agrees with interface toughness values in the literature measured using other test methods with the same material system. The effective kinematics of the test rig is measured using Digital Image Correlation (DIC) by studying the rotations and moments of a specially designed calibration specimen and comparing the results against finite element results. The DCB-UBM specimen and test method is a promising candidate for obtaining face sheet/core interface fracture toughnesses in sandwich composites.

KW - DCB-UBM

KW - Sandwich composite

KW - Mode-mixity

KW - CSDE

KW - Face sheet/core interface

U2 - 10.1016/j.engfracmech.2018.06.036

DO - 10.1016/j.engfracmech.2018.06.036

M3 - Journal article

VL - 203

SP - 208

EP - 223

JO - Engineering Fracture Mechanics

JF - Engineering Fracture Mechanics

SN - 0013-7944

ER -