Composite Materials Research Progress

More documents

Recommendations

Info

184 Giangiacomo Minak and Andrea Zucchelli for a general crisis of the laminate. In fact the PII,1 is followed by a small series of strain energy storing phases, PI,2 and PI,3, and a combination of sub-function of type II, III and IV highlighting a great material damage. The QI3 is characterized by a sentry function that mixes the behaviour of the studied UD and AP laminates. At the test beginning is visible a combination of sub-functions of type I and of type II with a predominant strain energy storing phase. This phase is characterized by the sequence of the following sub-functions: PI,1, PII,1, PI,2, PII,2 and PI,3. A delamination failure is revealed by the slope change of f corresponding to PII,3. After this failure a reduced energy storing capability is revealed by the PI,4 and the following drop PII,4 is due to the failure of the weakest ply inside the laminate. This first ply crisis is followed by a subfunction of type I, PI,5, that has a smooth trend due to the previous material damage. The damage corresponding to the sub-function PII,6 is due to the crisis of one of the stronger plies. After this laminate crisis the energy storing phase represented by the PI,6 is due to the stresses redistribution between the undamaged plies that are now working as springs in parallel. The analysis here described has been used to perform a quantitative estimation of the laminate damage and in particular the sentry function of each laminate has been used to perform a discretization of the stress-strain curve. As an example of this analysis we report the case of UD laminate type. f 40 35 30 25 20 15 10 5 f Stress-Strain Drops 0 0 0.000 0.003 0.005 0.008 0.010 Strain 0.013 0.015 0.018 0.020 Figure 11. Stress and f diagram versus strain, the most key drops of f are highlighted by means of gaps diagram. The analysis of the sentry function in figure 11 allows the identification of 10 drops on the basis of which the stress-strain curve was divided in order to calculate the Elastic modulus. 2500 2000 1500 1000 500 Stress (MPa)
Stress (MPa) Stress (MPa) Damage Evaluation and Residual Strength Prediction of CFRP Laminates … 185 2500 2000 1500 1000 500 0 2500 2000 1500 1000 Experimental Model 0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 0.02 Strain Figure 12. Stress-strain diagram and its discretization according to the key-drops. 500 Stress - Strain Model Young Modulus 0 0.0E+00 0 0.0025 0.005 0.0075 0.01 0.0125 0.015 0.0175 0.02 Strain 2.0E+05 1.8E+05 1.6E+05 1.4E+05 1.2E+05 1.0E+05 8.0E+04 6.0E+04 4.0E+04 2.0E+04 Figure 13. Discretized stress-strain curve and Elastic modulus according to the key-drops analysis. By means of a linear regression the Elastic modulus of the stress-strain curve corresponding to each strain interval was estimated. In figure 12 the discretized stress-strain curve is reported and overlapped to the original diagram. In figure 13 the discretized stressstrain curve and Elastic modulus values are reported. Young modulus (MPa)
Page 3:
COMPOSITE MATERIALS RESEARCH PROGRE
Page 6 and 7:
Copyright © 2008 by Nova Science P
Page 8 and 9:
vi Contents Chapter 9 Recent Advanc
Page 10 and 11:
viii Lucas P. Durand scale transiti
Page 12 and 13:
x Lucas P. Durand machine. In paral
Page 15 and 16:
In: Composite Materials Research Pr
Page 17 and 18:
Multi-scale Analysis of Fiber-Reinf
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
T300 fibers (Soden et al., 1998; Ag
Page 27 and 28:
Page 29 and 30:
1 I L = L : r v Multi-scale Analysi
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
I E ⎡0 ⎢ ⎢0 ⎢ ⎢ ⎢ ⎢0
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Applied macroscopic load Correspond
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Optimization of Laminated Composite
Page 69 and 70:
Page 71 and 72:
⎧σ x ⎫ ⎡ mE ⎪ ⎪ ⎢ x
Page 73 and 74:
and γ 2 γ 0 Optimization of Lamin
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
4 x 10 5 4 3 2 1 Compliance (Nmm) 0
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
3.5 3 2.5 2 1.5 1 Optimization of L
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121:
Page 124 and 125:
110 W.H. Zhong, R.G. Maguire, S.S.
Page 126 and 127:
112 Reinforcement: Advanced materia
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
130 Yuanxin Zhou, Hassan Mahfuz, Vi
Page 146 and 147:
132 Yuanxin Zhou, Hassan Mahfuz, Vi
Page 148 and 149: 134 Yuanxin Zhou, Hassan Mahfuz, Vi
Page 154 and 155: 140 Heat Flow (W/g) Heat Flow (W/g)
Page 158 and 159: 144 Material Yuanxin Zhou, Hassan M
Page 160 and 161: 146 SEM Analysis Yuanxin Zhou, Hass
Page 164 and 165: 150 Governing Equation For the fibe
Page 166 and 167: 152 ⎧ UU = ⎨ ⎩ ⎧ UD = ⎨
Page 170 and 171: 156 Stress (MPa) 120 80 40 0 Yuanxi
Page 180 and 181: 166 Giangiacomo Minak and Andrea Zu
Page 184 and 185: 170 ⎟ ⎞ ⎠ s ⎜ ⎛ ⎝ = a E
Page 202 and 203: 188 A B E (MPa) D 250000 200000 150
Page 204 and 205: 190 D D 1.0 0.9 0.8 0.7 0.6 0.5 0.4
Page 218 and 219: 204 Conclusion Giangiacomo Minak an
Page 223 and 224: In: Composite Materials Research Pr
Page 225 and 226: Research Directions in the Fatigue
Page 241 and 242: Bending force [N] Research Directio
Page 249 and 250:
Research Directions in the Fatigue
Page 251 and 252:
Page 253 and 254:
Damage Variables in Impact Testing
Page 255 and 256:
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
Page 263 and 264:
F peak [kN] 16 14 12 10 8 6 4 2 0 D
Page 265 and 266:
Page 267 and 268:
Page 269 and 270:
Page 271 and 272:
Page 273 and 274:
Eletromechanical Field Concentratio
Page 275 and 276:
Page 277 and 278:
Page 279 and 280:
Page 281 and 282:
Page 283 and 284:
MV/m. Eletromechanical Field Concen
Page 285 and 286:
Page 287:
Page 290 and 291:
276 S.C. Tjong developed in the pas
Page 292 and 293:
278 S.C. Tjong ultrasonic waves gen
Page 294 and 295:
280 S.C. Tjong applications. Goujon
Page 296 and 297:
282 S.C. Tjong nanoparticles were p
Page 298 and 299:
284 S.C. Tjong where DL is lattice
Page 300 and 301:
286 S.C. Tjong stress is temperatur
Page 302 and 303:
288 S.C. Tjong threshold stress res
Page 304 and 305:
290 S.C. Tjong NC Al, and the NC Al
Page 306 and 307:
292 S.C. Tjong (a) (b) Figure 19. T
Page 308 and 309:
294 S.C. Tjong Apart from forming u
Page 310 and 311:
296 S.C. Tjong [29] Saravanan, M.;
Page 312 and 313:
298 braids, 115 broadband, 211 bubb
Page 314 and 315:
300 endothermic, 139 endurance, 32
Page 316 and 317:
302 isostatic pressing, 279, 288 It
Page 318 and 319:
304 piezoelectricity, 261 pitch, 12
Page 320 and 321:
306 67, 69, 70, 71, 72, 73, 84, 94,
show all

Composite Materials Research Progress

Create successful ePaper yourself

Delete template?

Save as template?