reverse engineering – recent advances and applications - OpenLibra

More documents

Recommendations

Info

264 Reverse Engineering – Recent Advances and Applications Based on FEM analysis have been investigated the stress distribution and structural integrity of a maxillary complete denture. The study focused on fracture resistance evaluation of dentures, in the presence of structural defects of materials, which initiates denture’s cracking or fracture, before the estimated lifetime. Also, was analysed, through defectoscopy method, the porosity degree of dentures depending on the material they are made, and the influence of the defect size and location in denture, on the stress and strain state. 2. Material and methods 2.1 Mechanical properties of the material For this study, have been selected maxillary complete dentures from different acrylic resins obtained by two technologies: heat-curing material - Meliodent (Heraeus Kulzer, Senden, Germany) and light curing material - Eclipse Resin System (Dentsply International Inc.- DeguDent GmbH, Hanau Germany). The dentures were non-destructively evaluated using an Olympus stereomicroscope, Type SZX7, locating the defects and micro-cracks resulted from their technology, fig. 1-a, b. In most of dentures assessed, defects were located in the area indicated in Figure 1. Using an image processing system, QuickphotoMicro 2.2, was made an assessment of defects size, fig. 1-b. In the next step of the study, was performed an experimental program to determine the mechanical properties of the materials involved in the analysis. The materials have been prepared in accordance to the manufacturer’s recommendations, Table 1. The mechanical properties were determined by tensile tests on a testing machine, model Zwick Roell (Zwick GmbH & Co. KG, Ulm, Germany), according to ISO 527 standard and bending tests according to ASTM D 790 standard. The test results showed a brittle fracture behavior, which may indicate some vulnerabilty of this materials in the presence of defects. The area with high density of defects a) b) Fig. 1. Non-destructive evaluation of maxillary complete dentures: a) locating defects in denture; b) measurement of localised defects.
Reverse Engineering and FEM Analysis for Mechanical Strength Evaluation of Complete Dentures: A Case Study Brand Name Meliodent Heat Cure Eclipse Prosthetic Resin System Polymer: monomer ratio Batch No. (polymer/monomer) Description 34g:17mL 64713213/64713308 Base plate supplied as pre-packed material 030822 Heat polymerized Light – activated Table 1. The characteristics of acrylic resins included in this study 265 Polymerization procedure 7 hrs at 70° C and 1 hr at 100° C Visible blue light 2.2 Geometric modeling of the upper complete denture Finite element analysis was performed on geometric models, resulted after the complete dentures’ 3D scanning (with 3D laser scanner LPX1200, Roland) and image processing by ,,reverse engineering’’, taking into consideration the located defects. A thin layer of green dye (Okklean, Occlusion spray, DFS, Germany) was sprayed on the surface of the denture to increase its contrast for scanning. The denture was positioned on the rotating table of the 3D scanner and scanned with a scanning pitch of 0.1 x 0.1 mm. Scanning technique used is that of triangulation which is based on using a 3D non-contact active scanner. Non-contact active scanners emit some kind of radiation or light and exploit a camera to look for the location of the laser dot. Depending on how far away the laser strikes a surface, the laser dot appears at different places in the camera’s field of view. This technique is called triangulation because the laser dot, the camera and the laser emitter form a triangle, fig. 2. DZ Laser Object Fig. 2. Principle of laser triangulation sensor Sensor Lens The results of scanning process may be a point cloud (fig. 3) or a polygon mesh (fig. 4) having the shape of the scanned object. In a polygonal representation, the registered points are connected by straight edges forming a network of small plane triangular facets. After 3D scanning, the point cloud or polygon mesh are processed by reverse engineering technique and converted into a solid geometric model, fig. 5. Dz
Page 1 and 2:
REVERSE ENGINEERING - RECENT ADVANC
Page 5 and 6:
Contents Preface IX Part 1 Software
Page 9 and 10:
Preface Introduction In the recent
Page 11 and 12:
Preface XI and con’s related to t
Page 13 and 14:
Preface XIII the step-by-step appli
Page 17:
Part 1 Software Reverse Engineering
Page 20 and 21:
4 Reverse Engineering - Recent Adva
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
10 Reverse Engineering - Recent Adv
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
58 2. Model driven architecture: An
Page 76 and 77:
Page 78 and 79:
62 Fig. 1. Model, metamodels and tr
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
100 Reverse Engineering - Recent Ad
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
108 Table 1. Number of smoothers an
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 133 and 134:
1. Introduction 60 Surface Reconstr
Page 135 and 136:
Surface Reconstruction from Unorgan
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
1. Introduction A Systematic Approa
Page 151 and 152:
A Systematic Approach for Geometric
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
A Review on Shape Engineering and D
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Integrating Reverse Engineering and
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
Page 227 and 228:
Page 229 and 230: Integrating Reverse Engineering and
Page 231: Part 3 Reverse Engineering in Medic
Page 234 and 235: 218 Reverse Engineering - Recent Ad
Page 254 and 255: 238 5. Summary and discussions Reve
Page 284 and 285: 268 Fig. 6. A closed polygon mesh r
Page 288 and 289: 272 3. Results Reverse Engineering
Page 292: 276 Reverse Engineering - Recent Ad
show all

reverse engineering – recent advances and applications - OpenLibra

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

Delete template?

Save as template?