0
Research Papers

Impact Loading of Single Lap Joints of Dissimilar Lightweight Adherends Bonded With a Crash-Resistant Epoxy Adhesive

[+] Author and Article Information
R. Avendaño, M. Costa

Faculty of Engineering,
Institute of Science and Innovation in
Mechanical and Industrial Engineering (INEGI),
University of Porto,
Porto 4200-465, Portugal

R. J. C. Carbas

Faculty of Engineering,
Institute of Science and Innovation in
Mechanical and Industrial Engineering (INEGI);
Department of Mechanical Engineering,
Faculty of Engineering,
University of Porto,
Porto 4200-465, Portugal

F. J. P. Chaves, A. A. Fernandes

Department of Mechanical Engineering,
Faculty of Engineering,
University of Porto,
Porto 4200-465, Portugal

L. F. M. da Silva

Department of Mechanical Engineering,
Faculty of Engineering,
University of Porto,
Porto 4200-465, Portugal
e-mail: lucas@fe.up.pt

1Corresponding author.

Contributed by the Materials Division of ASME for publication in the JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY. Manuscript received January 12, 2016; final manuscript received July 13, 2016; published online August 9, 2016. Assoc. Editor: Toshio Nakamura.

J. Eng. Mater. Technol 138(4), 041019 (Aug 09, 2016) (10 pages) Paper No: MATS-16-1013; doi: 10.1115/1.4034204 History: Received January 12, 2016; Revised July 13, 2016

The use of lightweight materials in the automotive industry for structural parts has been increasing in recent years in order to reduce the overall vehicle's weight. New innovative lighter materials are being developed nowadays to accomplish that objective. In order to keep or even increase passenger's safety, structural parts made of these materials need to withstand static and impact loads within a range of different temperatures along the vehicle's life. The effect of these conditions when joining these dissimilar lighter materials is a critical issue to be considered when designing the car's body. In this paper, the strength under real car conditions of single lap joints (SLP) made of aluminum alloy (AA) bonded to carbon fiber reinforced polymer (CFRP) adherends was studied. A new crash-resistant epoxy adhesive was used to bond these lightweight materials and an extended characterization of its cohesive properties was carried out. The single lap joints were tested at temperatures of −30, +23, and +80 °C under quasi-static and impact loading. The data obtained was used to perform simple numerical models of the single lap joints under static and impact loads. The experimental results showed an expected increase of the joints strength with the strain rate. The joints behavior was highly influenced by the adherends, especially by the aluminum yielding at high and room temperatures. Delamination of the composite was obtained at low and room temperatures, which explained the strain rate dependence of the failure load. The numerical models predicted with good accuracy the strength of the joints under both static and impact loads.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

AA 6016 tensile stress–strain curves

Grahic Jump Location
Fig. 2

Geometry for the SP498/3 dog-bones according to the EN ISO 527-2 short specimen standard (dimensions in mm)

Grahic Jump Location
Fig. 3

SP498/3 properties at −30, 23, and 80 °C and two strain rates

Grahic Jump Location
Fig. 4

Geometry used for the DCB specimens (dimensions in mm)

Grahic Jump Location
Fig. 5

SP498/3 P–δ curves obtained from the three DCB specimens tested in mode I

Grahic Jump Location
Fig. 6

SP498/3 R-curves from the three DCB specimens tested in mode I

Grahic Jump Location
Fig. 7

SP498/3 P–δ curves obtained from three ENF tests (mode II)

Grahic Jump Location
Fig. 8

SP498/3 R-curves obtained from three ENF tests (mode II)

Grahic Jump Location
Fig. 9

Tg test diagram and setup used [26]

Grahic Jump Location
Fig. 10

Typical heating curve obtained in the Tg determination test

Grahic Jump Location
Fig. 11

SLJ specimens geometry (dimensions in mm)

Grahic Jump Location
Fig. 12

Assembling support for the impact test of SLJs

Grahic Jump Location
Fig. 13

Thermographic camera picture before a high temperature impact test

Grahic Jump Location
Fig. 14

Boundary conditions applied in the 2D static model

Grahic Jump Location
Fig. 15

Mesh definition for the overlap zone

Grahic Jump Location
Fig. 16

Triangular cohesive law defined for the adhesive

Grahic Jump Location
Fig. 17

True stress–true strain curve introduced for the AA adherend in the model

Grahic Jump Location
Fig. 18

Boundary conditions of the 2D impact model

Grahic Jump Location
Fig. 19

Quasi-static load versus displacement curves for CFRP-AA SLJs at different temperatures

Grahic Jump Location
Fig. 20

Failure modes of CFRP-AA SLJs under quasi-static loads at −30 (left), +23 (middle), and +80 (right)

Grahic Jump Location
Fig. 21

Failure mode at +23 °C for CFRP-AA SLJs where cohesive failure can be observed before the CFRP delamination

Grahic Jump Location
Fig. 22

Impact load versus displacement curves for CFRP-AA SLJs at different temperatures

Grahic Jump Location
Fig. 23

Failure modes of CFRP-AA SLJs under impact loads at −30 (left), +23 (middle), and +80 °C (right)

Grahic Jump Location
Fig. 24

Failure load versus temperature quasi-static and impact results for CFRP-AA SLJs

Grahic Jump Location
Fig. 25

FEM versus experimental results for the CFRP-AA SLJs under quasi-static loading

Grahic Jump Location
Fig. 26

Degradation (red area on the right) of adhesive SP498/3 in a static simulation with CFRP-AA SLJs

Grahic Jump Location
Fig. 27

FEM versus experimental results for the CFRP-AA SLJs under impact loading

Grahic Jump Location
Fig. 28

Contourplot of plasticstrain in the AA adherend

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In