View/Open - Scholarly Commons Home

More documents

Recommendations

Info

presented that quality concepts should be based upon and developed around, the philosophy of prevention. The Taguchi Method is a multi-stage process as follows: Systems Design, Parameter Design, and Tolerance Design. Systems Design: The centre of the systems design is about finding out new ideas, concepts to provide new, improved products to customers. It includes designing and testing systems based on the scientist‟s understanding of selected materials, parts and technology. It also involves innovation, creativity from different fields of sciences and technology. Parameter Design: Parameter design searches to determine the factor levels that make the best performance of the process under study. It aims to improve the uniformity of the product which could be done at no additional cost to the company. The nominal condition was chosen so that the effect of uncontrollable noise factors causes the least variation of system performance. Noise - Performance Statistics (NPS) are used to identify „Control‟ factors. Signal-to-Noise ratios are also used to evaluate the effect of „Noise‟ on the system. An unreactive system will have a high Signal to noise ratio. Noise Factors: The „noise‟ factors can be classified on the basis of being either internal or external to the system, as either inner or outer noise. Inner Noise is the type of variation from specification, which can be described as product noise. Outer Noise is the variation which is imposed by circumstances, for e.g., temperature, humidity, wear and tear effects. Tolerance Design: Tolerance design is a way to perfect the results of the parameter design by squeezing the tolerance of factors with prominent bear on the product. 90
Such steps usually identify the need of innovation and identification of better machinery, parts etc. Taguchi methodology stresses the importance of the middle stage in the total design process, which is often neglected in industrial design practice. The methodology involves recognising the parameters which are under the control of the scientist, and then the setting up of a series of experiments to find that subset of those parameters which has the most influence on the variation and performance of the design. The scientist is hence able to point out the aspects of the design which most influence the result of the design process. Another aspect of the Taguchi methodology is the "Taguchi loss function" or "quality loss function" which says that there is an increasing loss from the ideal or target value of any design parameter. A larger deviation from target implies the greater loss. The idea of loss being dependent on variation is long established in design theory, and at a systems level is related to the benefits and costs linked to dependability. Variability unavoidably means waste of any kind - but it is impossible to have zero variability. Thus if performance falls anywhere within the range, it is regarded as acceptable, if it falls outside that range it is not acceptable. The Taguchi methodology guides that a more realistic function should used based on the square of the deviation from the ideal target, i.e. that customers get more dissatisfied as performance varies from ideal. The Taguchi loss function strategy stresses for reducing variability and to strive for a process mean that is equal to the nominal specification. Companies using the basic methodology of examining main specifications and striving for a mean of measurements equating to nominal specification values, along with a reduction in data variability, can expect to produce products that are expected by customers to have higher, more consistent quality. Taguchi recommends two-level factors for an initial experiment. If the factors and their interactions are less than 7, a possible matrix is an eight-trial orthogonal array, which is labelled as an L8 matrix. 91
Page 1 and 2:
An Investigation into curved layer
Page 3 and 4:
Contents Abstract..................
Page 5 and 6:
3.5.2 Fabepoxy.....................
Page 7 and 8:
methodology to print simple curved
Page 9 and 10:
List of Figures 1.1 The Rapid proto
Page 11 and 12:
4.3 Parts being tested with Hounsfi
Page 13 and 14:
List of Abbreviations 3D: Three dim
Page 15 and 16:
Fig 1.1 The Rapid prototyping Cycle
Page 17 and 18:
1.1.1 Stereolithography Stereolitho
Page 19 and 20:
The object to be made is first mode
Page 21 and 22:
1.1.5 Laser Engineered Net Shaping
Page 23 and 24:
1.2 Fused Deposition Modeling A det
Page 25 and 26:
Fig 1.8 Deposition Head Different t
Page 27 and 28:
900mc is capable of producing parts
Page 29 and 30:
noted that the parts built in this
Page 31 and 32:
structure. Honeycomb scaffold archi
Page 33 and 34:
optimal direction to build a part t
Page 35 and 36:
processing treatment was analyzed w
Page 37 and 38:
The actual influence of the curved
Page 39 and 40: Separating the Main part with its s
Page 41 and 42: limited to simple models. It could
Page 43 and 44: Fig 2.2 Faces, Edges and Vertices o
Page 45 and 46: 2.1.5 Constructive Solid Geometry C
Page 47 and 48: A STL file is a triangular represen
Page 49 and 50: Fig 2.8 A sample Binary STL File Sl
Page 51 and 52: Different processes may either vary
Page 53 and 54: At the very outset of generating th
Page 55 and 56: and correction of each point to sat
Page 57 and 58: apid prototyping machine are remove
Page 59 and 60: Fig 2.13 Main Part Fig 2.14 Support
Page 61 and 62: As this text file is to be used wit
Page 63 and 64: mounted to the axes carriage. Timin
Page 65 and 66: Fig 3.1 The deposition head At the
Page 67 and 68: 3.2.3 Assembling Electronics and ca
Page 69 and 70: microcontroller is now disconnected
Page 71 and 72: The relationship between test point
Page 73 and 74: on the mechanical properties and po
Page 75 and 76: 3.5.1 Silicone with other materials
Page 77 and 78: Fab@home machine. Since our require
Page 79 and 80: are printed using the two suitable
Page 81 and 82: The support structure‟s dimension
Page 83 and 84: machine Fig 3.13 Flat and curved la
Page 85 and 86: 4.1 Experimental conditions Chapter
Page 87 and 88: have many factors from contention a
Page 89: 4.3 Taguchi methods There are two t
Page 93 and 94: Nominal is best Larger is better S
Page 95 and 96: Control of material flow - The lead
Page 97 and 98: Fig 4.3 Parts being tested with Hou
Page 99 and 100: values in all cases are almost doub
Page 101 and 102: level. The other parameters were in
Page 103 and 104: The finite element method has had a
Page 105 and 106: performance of finished FDM parts [
Page 107 and 108: ehaviour with failure occurring at
Page 109 and 110: Fig. 2 (a) is the thin curved part
Page 111 and 112: Table 5.1 Property data: Fabepoxy M
Page 113 and 114: optimum number. The final finite el
Page 115 and 116: Fig. 5.11 Load and boundary conditi
Page 117 and 118: overall deflection pattern of two s
Page 119 and 120: Fig. 5.13 Variation of compressive
Page 121 and 122: Fig. 5.15 shows the overall deforma
Page 123 and 124: The effectiveness of the deposition
Page 125 and 126: [11] M. Greul, T. Pintat, M. Greuli
Page 127 and 128: [32] Philip J. Ross, 1988, “Taguc
show all

View/Open - Scholarly Commons Home

Create successful ePaper yourself

Delete template?

Save as template?