cross section crash boxes

More documents

Recommendations

Info

Figure 1. 4. Commercial crash boxes in various geometries. Two methodologies have been recently applied to improve the energy absorption performances of crash boxes. These are the use of multiple-cell structure and filling the crash boxes with a with light-weight metallic foam. Aluminum foam filling particularly has received much interest from both academia and industry since they have relatively very low density as compared with the foams of other metals. Unlike polymeric counterparts, aluminum foams are nonflammable and absorb much more energy under increasingly high deformation loads. In addition, aluminum foams have capabilities for the attenuating noise and vibration. The gear wheel noise emissions were reported to be reduced up to 10 dB (A), with the use of Al foam filling, at the full transmission of torque and turning speed with a 25% weight saving (Stöbener and Rausch 2009). Aluminum foams have recently been considered as the candidate materials for the crash safety applications. Despite many studies on Al foam filling of the columns in the literature, which are reviewed in Chapter 3 of this thesis, there has been no extensive study on Al foam filling of commercial crash boxes experimentally and numerically. The motivations of the present thesis include (a) assessing the effect of Al foam filling on the crash performance of a commercial crash box, (ii) modeling the associated crushing behavior of the filled boxes and verifying the model results with experiments and (iii) optimization of the filled crash boxes made of different materials and alloys. It is believed that with the results of this thesis, many aspects of the Al foam filling of commercially available crash boxes will be clarified and the limits of foam filling in terms crash performance and cost will be determined. In Chapter 2 of the thesis, the production methods and mechanical behavior of Al closed cell metal foams are reviewed. Chapter 3 reviews the crash behavior of circular and rectangular cross- 4
sectioned empty and foam filled crash box structures along with the used crash analysis methodologies and terminologies. The motivations for the research conducted in this thesis are given in Chapter 4. Chapter 5 includes the experimental methods of mechanical testing of the used Al foam filler and the crash box material, 1050H14 aluminum alloy and the production steps of empty and foam filled crash boxes. The details of the numerical simulations are outlined in Chapter 6. The results of experimental and simulation studies are given in Chapter 7 and 8, respectively. The results of optimization of partially aluminum foam filled boxes with Response Surface Methodology are analyzed in Chapter 9. Chapter 10 discusses the crash efficiencies of partially foam filled crash boxes. Conclusions are drawn in Chapter 10 along with suggested future studies. 5
Page 1 and 2: OPTIMIZATION OF THE AXIAL CRUSHING
Page 3 and 4: ACKNOWLEDGEMENTS My PhD quest has b
Page 5 and 6: ÖZET KAPALI HÜCRELİ ALUMİNYUM K
Page 7 and 8: CHAPTER 4 EXPERIMENTAL DETAILS ....
Page 9 and 10: CHAPTER 8 ALUMINUM CRASH BOX OPTIMI
Page 12 and 13: Figure 3.7. Simulations of the defo
Page 14 and 15: Figure 4.9. Dimensions of tensile t
Page 16 and 17: Figure 6.21. Sequential deformation
Page 18 and 19: Figure 7.20. Sequential deformation
Page 20 and 21: LIST OF TABLES Table Page Table 4.1
Page 22 and 23: Figure 1. 1. The body in white stru
Page 26 and 27: CHAPTER 2 AL CLOSED CELL FOAMS: PRO
Page 28 and 29: The processing methods and mechanic
Page 30 and 31: Figure 2. 5 The preferred particle
Page 32 and 33: Figure 2. 8. Typical cellular struc
Page 34 and 35: Figure 2. 10. Manufacturing cost of
Page 36: Figure 2. 12. Laser assisted foamed
Page 41 and 42: Figure 2.16. Shear strength, normal
Page 43 and 44: Figure 2. 19. Yield strength vs. re
Page 45 and 46: Figure 2. 21. Unit cell geometry an
Page 47 and 48: Figure 2. 24. Load-displacement cur
Page 49 and 50: Figure 2. 26. The photographs of a
Page 51 and 52: CHAPTER 3 CRUSHING BEHAVIOR OF TUBU
Page 53 and 54: Figure 3.2. Diamond deformation mod
Page 57 and 58: deformation mode transition from ax
Page 59 and 60: Figure 3.8. Energy absorption of qu
Page 61: (a) (c) Figure 3.10. Deformation mo
Page 65 and 66: (a) (b) Figure 3.13. a) Schematic o
Page 67 and 68: (a) (b) (c) Figure 3.15. a) Load-di
Page 72 and 73: Figure 3.18. The crush terminology.
Page 75 and 76:
The quasi-static compression behavi
Page 77 and 78:
Figure 3.22. The variation of speci
Page 79 and 80:
Figure 3.24. Deformation modes of e
Page 81 and 82:
Figure 3.27. SEA values of empty an
Page 83 and 84:
Figure 3.29. (cont.) 3.5. Motivatio
Page 85 and 86:
CHAPTER 4 EXPERIMENTAL DETAILS 4.1.
Page 87 and 88:
(a) (b) Figure 4.3.Pictures of a) f
Page 89 and 90:
oxes are shown in Figure 4.6. The l
Page 91 and 92:
Figure 4.7. The method of trigger m
Page 93 and 94:
4.4. Compression Tests of Crash Box
Page 95 and 96:
4.5.2. Uniaxial Compression Testing
Page 97 and 98:
Table 4.1 (Cont.) G1 T3 F2 G1T3F2 3
Page 99 and 100:
Table 4.2 (Cont.) G1 T2.5 WP F2 G1T
Page 101:
CHAPTER 5 SIMULATION AND OPTIMIZATI
Page 105:
considered in axial and transverse
Page 109 and 110:
were constrained. Since the width o
Page 116 and 117:
5.4. The Crashworthiness Optimizati
Page 118 and 119:
great effect on the crushing behavi
Page 120:
CHAPTER 6 EXPERIMENTAL RESULTS 6.1.
Page 124 and 125:
Figure 6.3.Tensile stress-strain cu
Page 126 and 127:
(a) (b) Figure 6.5. Sequential defo
Page 128 and 129:
plate (Figure 6(b)). The trigger is
Page 130 and 131:
(a) (b) Figure 6.9. Deformation seq
Page 132 and 133:
Figure 6.12. Sequential deformation
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Figure 6.18. (cont.) (c) (a) (b) Fi
Page 140 and 141:
Figure 6.20.(cont.). (b) (c) 6.5.4.
Page 142 and 143:
Figure 6.21.(cont.) (b) (c) 122
Page 144 and 145:
Figure 6.22.(cont.) (c) Figure 6.23
Page 146 and 147:
Figure 6.24.(Cont.) (b) (c) (a) Fig
Page 148 and 149:
Figure 6.26.(cont.) (b) (c) 6.6. Dy
Page 150 and 151:
Figure 6.27. (cont.) (b) (c) 130
Page 152 and 153:
CHAPTER 7 MODELING RESULTS OF FOAM,
Page 154 and 155:
experimental tensile stress-strain
Page 156 and 157:
significant effect of weld seem ope
Page 158 and 159:
Figure 7.7. Deformation photo of fi
Page 160 and 161:
Figure 7.11. Deformation photos of
Page 162 and 163:
(a) (b) (c) Figure 7.14. Load-displ
Page 164 and 165:
7.4. Simulation of Empty and Partia
Page 166 and 167:
Figure 7.16. (cont.) (c) (a) Figure
Page 168 and 169:
(a) (b) Figure 7.18. Sequential def
Page 170 and 171:
Figure 7.19. (cont.) (b) (c) 150
Page 172 and 173:
Figure 7.20. (cont.) (c) (a) Figure
Page 174 and 175:
Page 176 and 177:
Page 178:
(a) (b) Figure 7.26. Experimental a
Page 182 and 183:
The constructed response surface of
Page 184:
Table 8.1. R 2 , Radj 2 and RMSE va
Page 187 and 188:
(a) (b) Figure 8.7. Response surfac
Page 189 and 190:
an empty tube wall thickness higher
Page 192 and 193:
where, K is a dimensionless constan
Page 194 and 195:
The dynamic simulation and analytic
Page 196:
Figure 9.4. (cont.) (c) (d) Figure
Page 199 and 200:
Figure 9.6. (cont.) (c) (d) (a) Fig
Page 203 and 204:
Equation 9.7 can also be rewritten
Page 206:
(a) (b) Figure 9.10. Energy-absorbi
Page 209 and 210:
Figure 9.11. (cont.) (d) The variat
Page 211 and 212:
foam filling were evaluated. The re
Page 213 and 214:
13. The interaction between foam fi
Page 215 and 216:
Arora, J. S.,2004,Introduction to O
Page 217 and 218:
Dannemann, K. A. and Lankford, J.,
Page 219 and 220:
Hall, I. W., Guden, M. and Yu, C. J
Page 221 and 222:
Kim, D-K. and Lee, S., 1999, Impact
Page 223 and 224:
Mamalis, A. G., Manolakos, D. E., I
Page 225 and 226:
Pugsley, A. G. and Macaulay, M., 19
Page 227 and 228:
T. Miyoshi, M. Itoh S. Akiyama A. K
Page 229:
Zhao, H., Elnasri, I. and Girard, Y
show all

cross section crash boxes

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?