Abstract

Heavily cross-linked epoxy was characterized under different types of loading. The scope of work involves detailed testing procedures utilizing high-precision digital image correlation (DIC) system for all strain measurements. Fractographic analyses using scanning electron microscopy (SEM) were also provided. Besides, computed tomography (CT) scans were employed to characterize existing manufacturing imperfections, i.e., voids. Numerical modeling using extended finite element method (XFEM) utilizing the actual microstructure is conducted. Testing results and fractographic analyses showed that microvoids led to failure initiation at micro lengths. An unstable fracture behavior dominated the final failure under different types of loading. Global plastic deformation was observed in the case of uniaxial tension, while local plasticity was observed in specimens under three-point loading. It can be concluded that epoxies failure under a combined state of stresses is sophisticated, and straightforward stress/strain-based failure criteria are not well-suited for failure predictions.

References

References
1.
Mallick
,
P. K.
,
2007
,
Fiber-Reinforced Composites: Materials, Manufacturing, and Design.
, 3rd ed.,
CRC Press
,
New York
.
2.
Bauer
,
R. S.
,
Stewart
,
S. L.
, and
Stenzenberger
,
H. D.
,
2000
,
Composite Materials, Thermoset Polymer‐Matrix
, Kirk‐Othmer Encyclopedia of Chemical Technology,
John Wiley & Sons, Inc
.
3.
Uygunoglu
,
T.
,
Gunes
,
I.
, and
Brostov
,
W.
,
2015
, “
Physical and Mechanical Properties of Polymer Composite With High Content
,”
Mater. Res.
,
18
(
6
), pp.
1188
1196
. 10.1590/1516-1439.009815
4.
Wang
,
Z.
,
Liu
,
F.
,
Liang
,
W.
, and
Zhou
,
L.
,
2013
, “
Study on Tensile Properties of Nanoreinforced Epoxy Polymer: Macroscopic Experiments and Nanoscale FEM Simulation Prediction
,”
Adv. Mater. Sci. Eng.
,
2013
.
5.
Pulungan
,
D.
,
Lubineau
,
G.
,
Yudhanto
,
A.
,
Yaldiz
,
R.
, and
Schijve
,
W.
,
2017
, “
Identifying Design Parameters Controlling Damage Behaviors of Continuous Fiber-Reinforced Thermoplastic Composites Using Micromechanics as a Virtual Testing Tool
,”
Int. J. Solids Struct.
,
117
, pp.
177
190
. 10.1016/j.ijsolstr.2017.03.026
6.
Kalantari
,
M.
,
Dong
,
C.
, and
Davies
,
I. J.
,
2017
, “
Effect of Matrix Voids, Fibre Misalignment and Thickness Variation on Multi-objective Robust Optimization of Carbon/Glass Fibre-Reinforced Hybrid Composites Under Flexural Loading
,”
Composites, Part B
,
123
, pp.
136
147
. 10.1016/j.compositesb.2017.05.022
7.
Li
,
Y.
,
Stier
,
B.
,
Bednarcyk
,
B.
,
Simon
,
J. W.
, and
Reese
,
S.
,
2016
, “
The Effect of Fiber Misalignment on the Homogenized Properties of Unidirectional Fiber Reinforced Composites
,”
Mech. Mater.
,
92
, pp.
261
274
. 10.1016/j.mechmat.2015.10.002
8.
Wang
,
Z.
,
Yu
,
T.
,
Bui
,
T. Q.
,
Trinh
,
N. A.
,
Luong
,
N. T. H.
,
Duc
,
N. D.
, and
Doan
,
D. H.
,
2016
, “
Numerical Modeling of 3-D Inclusions and Voids by a Novel Adaptive XFEM
,”
Adv. Eng. Software
,
102
, pp.
105
122
. 10.1016/j.advengsoft.2016.09.007
9.
Hagstrand
,
P. O.
,
Bonjour
,
F.
, and
Månson
,
J. A. E.
,
2005
, “
The Influence of Void Content on the Structural Flexural Performance of Unidirectional Glass Fibre Reinforced Polypropylene Composites
,”
Composites Part A
,
36
(
5
), pp.
705
714
. 10.1016/j.compositesa.2004.03.007
10.
Liebig
,
W. V.
,
Leopold
,
C.
, and
Schulte
,
K.
,
2013
, “
Photoelastic Study of Stresses in the Vicinity of a Unique Void in a Fibre-Reinforced Model Composite Under Compression
,”
Compos. Sci. Technol.
,
84
, pp.
72
77
. 10.1016/j.compscitech.2013.04.011
11.
Liebig
,
W. V.
,
Viets
,
C.
,
Schulte
,
K.
, and
Fiedler
,
B.
,
2015
, “
Influence of Voids on the Compressive Failure Behaviour of Fibrereinforced Composites
,”
Compos. Sci. Technol.
,
117
, pp.
225
233
. 10.1016/j.compscitech.2015.06.020
12.
Van Der Meer
,
F. P.
,
Sluys
,
L. J.
,
Hallett
,
S. R.
, and
Wisnom
,
M. R.
,
2012
, “
Computational Modeling of Complex Failure Mechanisms in Laminates
,”
J. Compos. Mater.
,
46
(
5
), pp.
603
623
. 10.1177/0021998311410473
13.
Lachaud
,
F.
,
Espinosa
,
C.
,
Michel
,
L.
,
Rahme
,
P.
, and
Piquet
,
R.
,
2015
, “
Modelling Strategies for Simulating Delamination and Matrix Cracking in Composite Laminates
,”
Appl. Compos. Mater.
,
22
(
4
), pp.
377
403
. 10.1007/s10443-014-9413-4
14.
Pawar
,
P. M.
, and
Ganguli
,
R.
,
2006
, “
Modeling Progressive Damage Accumulation in Thin Walled Composite Beams for Rotor Blade Applications
,”
Compos. Sci. Technol.
,
66
(
13
), pp.
2337
2349
. 10.1016/j.compscitech.2005.11.033
15.
Pollayi
,
H.
, and
Yu
,
W.
,
2014
, “
Modeling Matrix Cracking in Composite Rotor Blades Within VABS Framework
,”
Compos. Struct.
,
110
(
1
), pp.
62
76
. 10.1016/j.compstruct.2013.11.012
16.
Bieniaś
,
J.
,
De¸bski
,
H.
,
Surowska
,
B.
, and
Sadowski
,
T.
,
2012
, “
Analysis of Microstructure Damage in Carbon/Epoxy Composites Using FEM
,”
Comput. Mater. Sci.
,
64
, pp.
168
172
. 10.1016/j.commatsci.2012.03.033
17.
Esna Ashari
,
S.
, and
Mohammadi
,
S.
,
2012
, “
Fracture Analysis of FRP-Reinforced Beams by Orthotropic XFEM
,”
J. Compos. Mater.
,
46
(
11
), pp.
1367
1389
. 10.1177/0021998311418702
18.
Talreja
,
R.
,
2014
, “
Assessment of the Fundamentals of Failure Theories for Composite Materials
,”
Compos. Sci. Technol.
,
105
, pp.
190
201
. 10.1016/j.compscitech.2014.10.014
19.
Fard
,
M. Y.
,
2011
, “Nonlinear Inelastic Mechanical Behavior of Epoxy Resin Polymeric Materials,” Ph.D. diss., Arizona State University.
20.
Wu
,
E. M.
, and
Tsai
,
S. W.
,
1971
, “
A General Theory of Strength for Anisotropic Materials
,”
J. Compos. Mater.
,
5
(
1
), pp.
58
80
. 10.1177/002199837100500106
21.
Hinton
,
M. J.
,
Kaddour
,
A. S.
, and
Soden
,
P. D.
,
2002
, “
A Comparison of the Predictive Capabilities of Current Failure Theories for Composite Laminates, Judged Against Experimental Evidence
,”
Compos. Sci. Technol.
,
62
(
12–13
), pp.
1725
1797
.
22.
Christensen
,
R. M.
,
2001
, “A Survey of and Evaluation Methodology for Fiber Composite Material Failure Theories,”
Mechanics for a New Mellennium
,
H.
Aref
, and
J. W.
Philips
, eds.,
Springer
,
Dordrecht
.
23.
Isaac
,
M. D.
, and
Ori
,
I.
,
2013
,
Engineering Mechanics of Composite Materials
,
Oxford University Press
,
New York
, Vol.
2
, pp.
1
403
.
24.
Daniel
,
I. M.
,
Daniel
,
S. M.
, and
Fenner
,
J. S.
,
2018
, “
A New Yield and Failure Theory for Composite Materials Under Static and Dynamic Loading
,”
Int. J. Solids Struct.
,
148–149
, pp.
79
93
. 10.1016/j.ijsolstr.2017.08.036
25.
Camanho
,
P. P.
,
Arteiro
,
A.
,
Melro
,
A. R.
,
Catalanotti
,
G.
, and
Vogler
,
M.
,
2015
, “
Three-Dimensional Invariant-Based Failure Criteria for Fibre-Reinforced Composites
,”
Int. J. Solids Struct.
,
55
, pp.
92
107
. 10.1016/j.ijsolstr.2014.03.038
26.
Hashin
,
Z.
, and
Rotem
,
A.
,
1973
, “
A Fatigue Failure Criterion for Fiber Reinforced Materials
,”
J. Compos. Mater.
,
7
(
4
), pp.
448
464
. 10.1177/002199837300700404
27.
Dávila
,
C. G.
,
Camanho
,
P. P.
, and
Rose
,
C. A.
,
2005
, “
Failure Criteria for FRP Laminates
,”
J. Compos. Mater.
,
39
(
4
), pp.
323
345
. 10.1177/0021998305046452
28.
Daniel
,
I. M.
,
2015
, “
Constitutive Behavior and Failure Criteria for Composites Under Static and Dynamic Loading
,”
Meccanica
,
50
(
2
), pp.
429
442
. 10.1007/s11012-013-9829-1
29.
Asp
,
L. E.
,
Berglund
,
L. A.
, and
Talreja
,
R.
,
1996
, “
A Criterion for Crack Initiation in Glassy Polymers Subjected to a Composite-Like Stress State
,”
Compos. Sci. Technol.
,
56
(
11
), pp.
1291
1301
. 10.1016/S0266-3538(96)00090-5
30.
Lambert
,
J.
,
Chambers
,
A. R.
,
Sinclair
,
I.
, and
Spearing
,
S. M.
,
2012
, “
3D Damage Characterisation and the Role of Voids in the Fatigue of Wind Turbine Blade Materials
,”
Compos. Sci. Technol.
,
72
(
2
), pp.
337
343
. 10.1016/j.compscitech.2011.11.023
31.
Nikishkov
,
Y.
,
Airoldi
,
L.
, and
Makeev
,
A.
,
2013
, “
Measurement of Voids in Composites by X-Ray Computed Tomography
,”
Compos. Sci. Technol.
,
89
, pp.
89
97
. 10.1016/j.compscitech.2013.09.019
32.
Elruby
,
A. Y.
, and
Nakhla
,
S.
,
2019
, “
Strain Energy Density Based Damage Initiation in Heavily Cross-Linked Epoxy Using XFEM
,”
Theor. Appl. Fract. Mech.
,
103
(
May
), p.
102254
. 10.1016/j.tafmec.2019.102254
33.
Eom
,
Y.
,
Boogh
,
L.
,
Michaud
,
V.
,
Sunderland
,
P.
, and
Månson
,
J. A.
,
2001
, “
Stress-Initiated Void Formaton During Cure of a Three-Dimensionally Constrained Thermoset Resin
,”
Polym. Eng. Sci.
,
41
(
3
), pp.
492
503
. 10.1002/pen.10746
34.
Verges
,
M. A.
,
Schilling
,
P. J.
,
Herrington
,
P. D.
,
Tatiparthi
,
A. K.
, and
Karedla
,
B. R.
,
2005
, “
X-Ray Computed Microtomography of Internal Damage in Fiber Reinforced Polymer Matrix Composites
,”
Compos. Sci. Technol.
,
65
(
14
), pp.
2071
2078
. 10.1016/j.compscitech.2005.05.014
35.
Wright
,
P.
,
Fu
,
X.
,
Sinclair
,
I.
, and
Spearing
,
S. M.
,
2008
, “
Ultra High Resolution Computed Tomography of Damage in Notched Carbon Fiber-Epoxy Composites
,”
J. Compos. Mater.
,
42
(
19
), pp.
1993
2002
. 10.1177/0021998308092211
36.
Baruchel
,
J.
,
Buffiere
,
J. Y.
,
Cloetens
,
P.
,
Di Michiel
,
M.
,
Ferrie
,
E.
,
Ludwig
,
W.
,
Maire
,
E.
, and
Salvo
,
L.
,
2006
, “
Advances in Synchrotron Radiation Microtomography
,”
Scr. Mater.
,
55
(
1 SPEC. ISS.
), pp.
41
46
. 10.1016/j.scriptamat.2006.02.012
37.
Otsu
,
N.
,
1979
, “
A Threshold Selection Method From Gray-Level Histograms
,”
IEEE Trans. Syst. Man Cybern.
,
9
(
1
), pp.
62
66
. 10.1109/TSMC.1979.4310076
38.
Hollister
,
S. J.
, and
Kikuchi
,
N.
,
1992
, “
A Comparison of Homogenization and Standard Mechanics Analyses for Periodic Porous Composites
,”
Comput. Mech.
,
10
(
2
), pp.
73
95
. 10.1007/BF00369853
39.
Simulia
,
2013
,
Abaqus 6.14 Documentation
,
Dassault Systèmes Simulia Corp.
,
Providence, RI
.
You do not currently have access to this content.