A
Advanced Subsonic Technology Composite Wing Program (NAS1-20546),
252
aerodynamic lift loads,
230
alternate joint concepts,
259–66
categories of damage and defect considerations,
266
damage tolerance analysis considerations,
265
load vs displacement data,
262
lower cover panel for stitched/RFI composites technology,
260
scaling and hybrids,
264–6
X-48B Blended Wing Body flight research vehicle,
264
design considerations,
229
designing for damage in composites,
248
environmental considerations,
232–41
Astrostrike and Dexmet,
235
effects of lightning strike protection,
237
impact damage due to hail,
240
lightning strike zones as defined in SAE ARP5414,
236
microcracking due to combined thermal-moisture cycling,
238
moisture: rain and ice,
237–41
near-surface damage in honeycomb-sandwich structures,
240
failure mechanisms considerations in polymer matrix composites,
227–71
automated tape-laying machine,
268
comparison of residual strength vs damage,
271
direct braiding of I-beam cross-section and Robotic single-sided stitching,
269
forward section of Boeing 787 Dreamliner fuselage,
269
percentage growth in both commercial and military aircraft structure,
267
materials-based approaches,
248–55
impact damage in a composite laminate,
251
liquid-moulding and prepreg-based toughening,
251–2
low velocity impact damage,
250
toughening in prepregs,
249–51
non-environmental considerations,
241–8
aftermath of crash and fire of composite-based Air Force B-2 bomber,
245
collapsed MD-80 landing gear,
247
flame impingement from a simulated engine fire,
245
glass transition temperature schematic,
242
ground-based damage due to human error,
246–8
high-speed airflow,
243–4
preform-based toughening,
252–5
VARTM-processed multiaxial preforms,
254
structural considerations,
229–48
BVID schematic where the dent depth must be above predetermined critical size,
233
determination and design considerations for in-flight loads,
229–31
impact damage and delamination,
231–2
impacted untoughened carbon/epoxy composite,
232
ultimate-load wing up-bending test on 787 Dreamliner static test unit,
231
structures-based approaches,
255–66
alternate lay-up considerations,
256–9
variables influencing fuselage design,
257
American Society for Testing and Materials,
395
tensile strength half-life vs temperature for E-glass/polyester,
426
traverse flexure properties of E-glass/epoxy laminate,
427
ARALL (aramid-aluminium laminate),
266
artificial weathering,
423–5
automated tape-laying (ATL) machine,
267
automated tow placement (ATP),
268
C
carbon fibre reinforced plastic (CFRP),
56
chemical degradation,
401–6
chemical resistance of various glass fibres,
404
chemical resistance of various thermosetting resins,
407
chlorine degradation and HCl induced blistering of GRP,
405
failure of a GRP structure due to alkaline aqueous solution,
403
helical cracks in e-glass fibres exposed to H2SO4,
402
chemical recycling,
353–6
cracking technologies,
354–6
chemical resistance testing,
418–23
criteria for chemical resistance,
420
partial design factor
A2,
421
screw-jack test machines with samples,
423
strain corrosion test apparatus for cylindrical section,
421
closed mould forming methods,
333
coefficient of thermal expansion (CTE),
30
Comité Européen de Normalisation,
395
Commission Directive 200/53/EC,
339
Commission Directive 2002/96/EC,
339
compliance calibration method,
113
compression after impact (CAI),
231,
248,
258
polymer matrix composites,
382–8
axial crushing of composite tubes,
385
energy absorptions in quasi-static and dynamic tests,
387
energy dissipation mechanisms,
385–7
experimental and predicted load-displacement diagrams,
386
modeling of progressive crushing,
387–8
parameters in crashworthiness studies of composite tubes,
384
critical strain energy release rate,
113
critical stress intensity factor,
118
crystal plasticity theory,
98
F
FAA Flame Propagation test,
245
progress for polymer matrix composites,
3–22
aims of the first World-Wide Failure Exercise,
5–7
current activities,
17–22
description of available models,
design problems solved,
9–17
setting up test problems,
7–9
fatigue strength of SMC-R composites,
378
modulus degradation during fatigue cycling,
379
S-N diagrams of SMC-R25 and SMC-R65,
378
Federal Aviation Administration (FAA),
229
Federal Aviation Regulations (FAR),
229
fibre-dominated compressive failure
physics of fibre kinking in unidirectional plies,
184–203
experimental observations,
184–90
failure modes in unidirectional composites in longitudinal compression,
184
numerical modelling,
191–5
short-fibre recycled composites,
213–16
woven recycled composites,
216–18
two-dimensional woven composites,
203–12
analytical modelling,
208
experimental observations,
203–7
failure envelopes predicted by a finite fracture mechanics based criterion,
202
model development under pure longitudinal compression,
199
results for kink-band formation under pure longitudinal compression,
200
experimental observations,
184–90
combined in-plane shear and longitudinal compression failure envelopes,
188–9
fibre fracture during kink-band formation,
186
kink-band formation in notched unidirectional composites,
185
shear-driven fibre compressive failure in cross-ply single edge notch specimen,
190
through the thickness kink-band formation in cross-ply compact compression specimens,
187
failure envelope generated by FE micromechanical models and kink band,
195
failure envelopes generated by FE micromechanical compared to experimental data,
196–7
fibre deflection during kink-band propagation,
194
micromechanical FE models,
192
sequence of events for fibre kinking from FE micromechanical models,
193
failure modes in unidirectional composites in longitudinal compression,
184
fibre-reinforced plastics
environmental induced failure,
393–440
chemical agents and degradation mechanisms,
395–414
environmental conditioning and testing,
414–25
modelling and predictive analysis,
425–30
optimising chemical resistance and prevention of failure,
430–1
filament wood composites,
303
finite element method (FEM),
209
fixed-time conditioning,
416–17
four-point end-notched flexure (4ENF),
115–16
mode I fracture toughness of SMC-R,
377
fracture toughness testing
interlaminar fracture toughness testing,
111–17
ply-level fracture toughness testing,
119–25
polymer matrix composites,
110–26
ply-level fracture mechanisms from continuous fibre-reinforced composites,
111
standardised test methods for measurement of fracture toughness,
112
translaminar fracture toughness testing,
117–19
I
Illinois Institute of Technology Research Institute (IITRI),
140
in-plane mechanical testing,
134–66
assembled and disassembled Wyoming CLC jig,
143
Celanese and IITRI jigs schematic,
141
compression results for T300/914 CFRP,
147,
148
compression test results for T300/914
CFRP specimens waisted on all four surfaces,
149
compressive stress-strain curve,
146
disassembled compression jigs,
142
end-tab bonding arrangement for the reverse chamfer specimen,
145
failed compression specimens waisted on all four faces,
150
load introduction methods for compression tests,
140
parallel-sided compression specimen,
147
reverse chamfered specimen,
145
specimen configuration,
143–5
specimen configurations for ASTM D3410M, ICSTM and ASTM D695,
144
strain measurement,
145–6
stress-strain curve for T300/914 CFRP,
149
various compression jigs to the same scale,
141
four-point flexure arrangement,
163
recommended specimen dimensions,
164
schematic of possible failure modes,
165
specimen dimensions and testing arrangement,
164–5
three-point flexure arrangement,
162
variation of normal stress and shear stress in flexure test,
163
ASTM V-notched beam shear jig with specimen,
155
failure modes for the V-notched beam test,
157
hoop-wound thin-walled cylindrical specimen,
151
schematic of 10 ° off-axis specimen,
154
schematic of the ±45 ° tensile specimen,
152
shear stress-strain curve for the ±45 ° specimen,
153
shear stress vs deflection for UD specimen,
158
three-rail shear jig and specimen,
159
torsion of a thin-walled tube,
149–52
two- and three-rail shear tests,
158–60
two-rail shear jig and specimen,
159
uniaxial tension of a ±45 ° laminate,
152–3
uniaxial tension of a 10 ° off-axis laminate,
154
V-notched beam (Iosipescu) shear test method,
155–8
V-notched beam specimen,
155
V-notched rail shear,
160–1
V-notched rail shear test specimen,
161
grips and specimen alignment,
135–6
principal directions and stress components for an orthotropic material,
135
specimen for checking testing machine alignment,
136
tensile specimen for 0 ° and 90 ° aligned reinforcement,
137
tensile specimens for non-0 ° reinforcement,
137
tensile stress-strain plot for UD T300/914,
139
in-service conditions,
370–1
inclined waisted shear specimen (IWS),
171–2,
173
interlaminar fracture,
110
interlaminar fracture toughness testing,
111–17
mixed mode I/II testing,
116–17
MMB specimen configuration,
117
determination of correction factor for modified beam theory,
114
determination of
m for critical strain energy release rate,
114
double cantilever beam,
112–14
double cantilever beam specimen,
113
ELS specimen configuration,
115
4ENF specimen configuration,
116
four-point end-notched flexure,
115–16
International Standards Organisation (ISO),
130,
395
isophthalic neo-pentyl glycol (NPG),
398
M
‘make and test’ philosophy,
approaches to minimise impact,
46–9
controlling out defects,
47–8
designing out ‘defects’,
46–7
honeycomb core sandwich panel inspection,
49
in-process inspection,
48–9
avoidable defects in continuous fibre composites,
39–41
fibre wrinkling in corner of an autoclave moulded prepreg part,
41
gross fibre misalignment caused by mould loading forces,
40
gross fibre misalignment generated by minor lay-up error,
40
one potential lay-up defect generation mechanism,
39
out-of-plane fibre waviness caused by RTM preform manufacture process,
40
cause of failure in polymer matrix composites,
26–51
design of reinforcements and matrices that are less pronesensitive to defects,
49–50
managing variability in materials and processing,
50–1
impact of fibre misalignment defects on strength,
41–6
failed sample showing multiple delaminations,
44
failure initiation under transverse tension of defective corner moulding,
45
impact of defects on flexural strength,
42
misorientation of the plies in test samples,
43
ply wrinkling in test samples,
44
misaligned, wavy and wrinkled reinforcements,
33–46
avoidable defects in continuous fibres composites,
35
parts of complex geometry with no obvious fibre direction datum,
34
unavoidable factors in continuous fibre composites,
34–5
residual stresses and geometrical distortions,
29–31
thermally induced resin cracking in 3D woven block of composite,
31
sources of variability and defects in composite mouldings,
27–9
unavoidable factors,
35–9
fibre waviness in prepreg,
36
impact of woven cloth drape on tow geometry,
38
tow edge shapes in a tow steered laminate,
38
variability in fibre direction,
37
voidage and delaminations on in-plane and out-of-plane properties,
32–3
loading rig to generate a transverse tensile stress in a corner region,
33
failure of composite materials for surface vessels,
306–22
laminate material testing,
306
sandwich core behaviour,
306–8
failure of composite materials for underwater structures,
322–32
filament wound materials,
323–6
influence of impact on cylinder failure modes,
326–32
common marine composites,
304–5
polymer matrix composites failure
composite failures on racing yachts,
301
data from measurements of strains on multi-hull foil,
302
polymer matrix composites failure,
300–33
matrix microcracking,
191
mechanical impedance analysis (MIA),
287
thermoplastic matrix composites,
345–52
effect of recycling and glass fibre length,
352
effects of reprocessing on polymer, reinforcement and other additives,
350
experimental variables in PET mechanical recycling research,
349
possible changes on polymer component,
346
properties of 30% GF PA66,
351
variables in recycling,
347
thermoset matrix composites,
342–5
flexural properties of recycling of SMC to BMC,
343
weight percentages of glass, filler and resin fractions,
344
biaxial in-plane testing,
172–5
biaxial in-plane Arcan test,
175
off-axis specimens,
174–5
end-tab arrangement on test material subpanel,
131
fibre volume fraction,
132
specimen alignment,
132–3
specimen conditioning,
132
specimen preparation,
130–2
strain measurement,
133–4
tension and compression testing,
166–9
polymer matrix composites strength and stiffness testing,
129–77
constrained out-of-plane compression,
176
cruciform specimens,
175–6
microbuckling theory,
196
MiG-29 composite vertical stabiliser inspection,
290
ballistic testing of blades under tension load,
283–5
blade after hit (inlet hole),
285
blade after hit (outlet hole),
285
second stage of experiment,
283
ballistic testing of blades without any tension applied,
281–3
change in bullet velocity after spar penetration,
283
outlet hole – roving penetration,
282
implications for preventing failure,
285,
287–93
examples of data processing,
289–93
flaw size comparison in the disbond area for F-16 jet fighter,
292
flaw size comparison in the disbond area for MiG-29,
293
image processing of composite horizontal stabiliser inspection results,
292
image processing of MIA inspection results,
291
image processing of MiG-29 composite vertical stabiliser inspection results,
294
stress distribution in the bondline,
287
polymer matrix composites failure,
279–98
tests of residual strength and residual stiffness,
284,
286
final damage in residual strength test,
286
stiffness of the blades before and after the test,
286
trends in modelling composite failures,
293,
295–8
randomisation of material properties,
296–7
mixed mode bending (MMB),
116–17
modified beam theory,
113
glass transition temperature of epoxy resin,
397
osmotic blistering of GRP boat hull,
398
SEM image of poor and good adhesion between fibre and matrix,
396
tensile properties of hot/wet conditioned [0
2/90
2]
S cross-ply laminates,
400
tensile properties of hot/wet conditioned unidirectional laminates,
400
P
Piola–Kirchhoff stress,
100
plastic micro-buckling,
98–102
axial load vs axial displacement,
101
micromechanical deformation kinematics based on crystal plasticity theory,
99
resolved shear stress on slip system vs fire-heating time,
101
plastic waste disposal,
341
ply-level fracture toughness testing,
119–25
fibre dominated failure modes,
122–6
compact compression,
124–5
compact compression specimen,
125
compact tension specimen,
123
four-point bend specimen,
126
mode I fibre compressive failure,
124–6
mode I fibre tensile failure,
122–4
matrix dominated failure modes,
119–22
DCB loaded with pure moments,
120–1
four-point bend specimen,
122
mode I longitudinal intralaminar matrix failure,
120–1
mode I transverse intralaminar matrix failure,
121–2
unidirectional DCB specimen loaded with pure moments,
120
Polish Air Force Institute of Technology,
281
failure in automotive and transport applications,
368–90
automotive and road transportation applications,
369
common in-service conditions causing failure,
370–1
composites for crashworthy structures,
382–8
implications of preventing failure,
388–9
sheet moulding compound composites,
371–82
failure in defence applications,
279–98
implications for preventing failure,
285–93
trends in modelling composite failures in military applications,
293–8
failure in marine and offshore applications,
300–33
failure mechanisms considerations in design of aerospace structures,
227–71
design considerations,
229
designing for damage in composites,
248
materials-based approaches,
248–55
structural considerations,
229–48
structures-based approaches,
255–66
fibre-dominated compressive failure,
183–219
physics of fibre kinking in unidirectional plies,
184–203
two-dimensional woven composites,
203–12
low and medium velocity impact as a cause of failure,
53–74
computational models,
71–3
strength and stability after impact,
66–71
manufacturing defects as cause of failure,
26–51
approaches to minimise the impact of manufacturing defects,
46–9
misaligned, wavy and wrinkled reinforcements,
33–46
residual stresses and geometrical distortions,
29–31
sources of variability and defects in composite mouldings,
27–9
voidage and delaminations,
32–3
progress in failure criteria,
3–22
aims of the first World-Wide Failure Exercise,
5–7
current activities,
17–22
description of available models,
design problems solved,
9–17
setting up test problems,
7–9
plastic waste disposal,
341
properties of recovered fibres,
358–9
recovery techniques,
352–8
recycled carbon fibre in fluffy form,
358
strength and stiffness testing,
129–77
biaxial in-plane testing,
172–5
structural integrity of panels in fire,
79–106
material behaviour at elevated temperature,
86–9
other aspects of structural integrity in fire,
102–6
plastic micro-buckling,
98–102
sandwich panels skin wrinkling,
94–8
temperature distribution,
81–6
interlaminar fracture toughness testing,
111–17
ply-level fracture toughness testing,
119–25
translaminar fracture toughness testing,
117–19
printed circuit board (PCB),
131
progressive crushing,
387–8
progressive failure analysis,
296
example of polymer behaviour,
355
R
processes for biomass, energy and materials,
340
recovery techniques,
352–8
chemical recycling,
353–6
depolymerisation technologies,
356–8
thermal conversion methods,
352–3
short-fibre recycled composites,
213–16
compressive failure of short fibre rCFRPs with fibre bundles,
215
recycled composite with multiscale structure consisting of fibre bundles,
214
woven recycled composites,
216–18
mechanical response of woven rCFRP,
217
comparison of properties,
360
filler and nanoparticulates,
361
self-reinforcing materials,
361
properties of recovered fibres,
358–9
thermoplastic matrix composites,
345–52
thermoset matrix composites,
342–5
polymer matrix composites,
337–67
plastic waste disposal,
341
recovery techniques,
352–8
chemical recycling,
353–6
depolymerisation technologies,
356–8
thermal conversion methods,
352–3
reduced compact compression test set-up (rCC),
206
region of interest (RoI),
288
resin film infusion (RFI),
252
resin infusion under flexible tooling (RIFT),
131
resin transfer moulding (RTM),
252
problems of reuse in polymer composites,
340–1
S
sandwich core behaviour,
306–8
sandwich panels skin wrinkling,
94–8
wrinkling model in combined thermal-mechanical condition,
95
wrinkling stress vs fire-heating time,
97
shear-driven fibre compressive failure,
187–9
sheet moulding compound,
342
sheet moulding compound composites,
371–82
effect of stress concentration,
375–6
damage formation in SMC-R plate,
376
environmental effects,
381–2
tensile strength of SMC-R,
382
fatigue strength of SMC-R composites,
378
modulus degradation during fatigue cycling,
379
S-N diagrams of SMC-R25 and SMC-R65,
378
mode I fracture toughness of SMC-R,
377
damage on the back side of impacted SMC-R panel,
381
post-impact residual tensile properties,
380
properties of various composites,
372
tensile characteristics,
373–5
SMC-R25 and SMC-R65 composites tensile stress-strain diagrams,
373
tensile strength variation,
375
Weibull parameters for strengths of SMC-R28 and SMC-R50,
375
short beam shear test,
169
signal-to-noise ratio (SNR),
289
simple trigonometric scaling,
240
stacked shell method,
297–8
static fatigue tests,
422
Stefan-Boltzmann constant,
83
strain energy release rate,
112
structural fire integrity
computed buckling load vs heating time for sandwich panel,
93
computed buckling load vs heating time for single skin panel,
92
material behaviour at elevated temperature,
86–9
power form model of degradation with respect to temperature rise,
87
simplified power form model of degradation,
88
design of structural fire integrity,
105–6
failures induced by debonding, delamination and cracking,
104–5
plastic micro-buckling,
98–102
axial load vs axial displacement,
101
micromechanical deformation kinematics based on crystal plasticity theory,
99
resolved shear stress on slip system vs fire-heating time,
101
polymer matrix composite panels,
79–106
sandwich panels skin wrinkling,
94–8
wrinkling model in combined thermal-mechanical condition,
95
wrinkling stress vs fire-heating time,
97
temperature distribution,
81–6
temperature distribution and simplified temperature model for sandwich panels,
86
temperature-time response of the laminate,
84
thermal-mechanical model for composite panels,
82
thermal distortion,
102–4
influence of ratio of skin thickness to core thickness to non-dimensional curvature,
103
stress at the interface between unexposed skin and core,
104
composite materials failure,
306–22
laminate material testing,
306
sandwich core behaviour,
306–8
shear tests on core materials,
307
bonded stiffener assembly,
319
compression tests on high modulus composites,
322
lateral pressure loading of panels,
308
medicine ball soft impact test,
316
PVC foam core shear failure in sandwich under lateral pressure loading,
310
sandwich in-plane shear failures,
312
sandwich soft impact failure modes,
318
simulation of mast loading,
317–22
soft impact on aluminium honeycomb core sandwich panel,
317
tests on laminate and sandwich panels under transverse pressure,
309
top hat pull-off at 1 m/s,
320–1
Z-pins insertion in overlaminated region,
320
T
takeoff and landing loads,
230
tangent modulus method,
105
thermal conversion methods,
352–3
thermal distortion,
102–4
influence of ratio of skin thickness to core thickness to non-dimensional curvature,
103
stress at the interface between unexposed skin and core,
104
thermal gravimetric analysis (TGA),
88,
416
thermo-chemical recycling process,
213
SEM image of high temperature degraded woven CFRP laminate,
411
thermoplastic interleaves,
251
thermoplastic matrix composites,
345–52
thermoset interleaves,
251
thermoset matrix composites,
342–5
translaminar fracture,
111
translaminar fracture toughness testing,
117–19
eccentrically loaded single-edge-notch tension,
117–19
ECT recommended specimen dimensions,
118
typical load-displacement plot for ECT specimen,
119
constrained out-of-plane compression,
176
out-of-plane compression of constrained specimen,
176
cruciform specimens,
175–6
two-dimensional signal value evaluation,
293
two-dimensional woven composites
description and comparison between analytical and experimental results,
209–10
experimental observations,
203–7
detail of a tow failed by kinking in a twill specimen,
205
idealised laminate with different stacking configurations,
206
location of the failure relative to crimp region centre,
204
longitudinal compression of a 2 × 2 twill composite,
207
tows fail individually with significant out-of-plane movement,
205
finite element model used,
211
U
UCSD multi-axial fire test apparatus,
92
‘unambiguous manufacturing instruction sets’,
47
composite materials failure,
322–32
failure of filament wound materials,
323–6,
327
composite cylinders under hydrostatic pressure loading,
323
defects in carbon composite cylinders,
327
imploded glass and carbon reinforced composite tubes after pressure testing,
324
internal hoop strain measurements indicating Mode 2 buckling,
325,
326
local failure at tube end due to stress concentration,
324
influence of impact on cylinder failure modes,
326–32
change in implosion failure mode after impact,
328
failure of syntactic foams,
329–32
glass spheres used in syntactic foams,
330–1
impact damage in carbon/epoxy tube,
328
macrosphere syntactic foams,
331
mechanical response of syntactic foams under hydrostatic pressure loading,
332
syntactic foams properties,
329
V
vacuum-assisted resin transfer moulding (VARTM),
252
cause of failure in polymer matrix composites,
53–74
issues of impact on composites,
54
computational models,
71–3
damage types in impacted fibre reinforced laminates,
55
distribution of delaminations for a 48-ply and 16-ply laminate,
57
distribution through the thickness,
56
fibre damage in a 16-ply and 48-ply laminate,
57
response and delaminations due to 10 J impact,
59
wave phenomena and response types during impact,
58
delamination threshold load for various layups and plate geometries,
62
effect of fibre fracture on delamination size,
64
measured load and deflection histories during impact,
64
predicted and measured load vs deflection during impact,
63
strength and stability after impact,
66–71
averaged apparent compressive stress-strain curves,
71
damage width and panel properties on buckling strain,
68
damage width and panel properties on panel buckling strain,
68
damage zones and variation of material properties at two impact energies,
70
experimental delamination size vs velocity and theory,
66
relation between local strains and local stiffness,
69
tensile stress-strain curves,
70
thickness and material on compressive strength after impact,
67
virtual crack closure technique (VCCT),
298
W
Weibull distribution,
375
Whitney–Nuismer point-stress failure criterion,
376
World-Wide Failure Exercise (WWFE),
3–22
current activities,
17–22
description of available models,
World-Wide Failure Exercise (WWFE-1)
diagram showing the adopted process,
stage I: establishing a framework,
design problems solved,
9–17
brief description of the approaches of the originators of failure theories,
11–12
failure progression in glass/epoxy laminate under uniaxial tension,
15
list of major issues addressed in the exercise,
13
predictions of selected cases,
10,
12
summary of failure theories benchmarked in WWFE-1,
10
theoretical predictions of 19 failure criteria and test data for test case 3,
14
various failure models used in WWFE-1,
16
list of major issues addressed in the exercise,
13
setting up test problems,
7–9
details of the laminates and loading (test) cases used in the first exercise,
lamina and laminate coordinates and loading configurations,
World-Wide Failure Exercise-2 (WWFE-2),
17,
18–20
list of participants and their methodology involved,
19
methodologies used,
19–20
World-Wide Failure Exercise-3 (WWFE-3),
17,
20–2
details of test cases used,
21