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ÇUKUROVA UNIVERSITY INSTITUTE OF NATURAL AND APPLIED SCIENCES M.Sc. THESIS THE USE OF COMPOSITE MATERIALS IN AUTOMOTIVE INDUSTRY DEPARTMENT OF MECHANICAL ENGINEERING ADANA, 2010 ÇUKUROVA ÜNİVERSİTESİ FEN BİLİMLERİ ENSTİTÜSÜ THE USE OF COMPOSITE MATERIALS IN AUTOMOTIVE INDUSTRY A THESIS FOR DEGREE OF MASTER OF SCIENCE DEPARTMENT OF MECHANICAL ENGINEERING We certified that the thesis titled above was reviewed and approved for the award degree of the master of mechanical engineering by the board of jury on 31/05/ Prof. Dr. Melih BAYRAMOĞLU Prof. Dr. Necdet GEREN Doç. Dr. Nihat ÇELİK Supervisor Member Member This PhD Thesis is performed in Department of Mechanical Engineering of the Institute of Natural and Applied Sciences of Çukurova University. Registration No: Prof. Dr. İlhami YEĞİNGİL Director Institute of Natural and Applied Sciences Note: The use of tables, figures and photographs (original or referenced) from this thesis, without proper reference, is subject to provisions of Law 5846 concerning Intellectual Property and Artistic Creations. ABSTRACT M.Sc. THESIS THE USE OF COMPOSITE MATERIALS IN AUTOMOTIVE INDUSTRY MURAT ÖNŞEN UNIVERSITY OF ÇUKUROVA INSTITUTE OF NATURAL AND APPLIED SCIENCES DEPARTMENT OF MECHANICAL ENGINEERING Supervisor: Prof.Dr. Melih BAYRAMOĞLU Year: 2010, Pages: 131 Jury : Prof. Dr. Melih BAYRAMOĞLU Prof. Dr. Necdet GEREN Assoc. Prof. Dr. Nihat ÇELİK The automotive industry's use of structural composite materials began in the 1950s. Since those early days, it has been demonstrated that composites are lightweight, fatigue resistant and easily moulded to shape in other words, a seemingly attractive alternative to metals. However, there has been no widespread switch from metals to composites in the automotive sector. This is because there are a number of technical issues relating to the use of composite materials that still need to be resolved including accurate material characterization, manufacturing and joining. This paper reports composite materials determining by Ashby s material selection technique usage in automotive industry. Especially bus exterior and interior components manufacturing by fiber reinforced polymers (FRP) are used in this master thesis. Keywords: Material selection, composite materials, bus components, Ashby s technique, Fiber reinforced polymers I ÖZ YÜKSEK LİSANS TEZİ OTOMOTİV SANAYİNDE KOMPOZİT MALZEMELERİN KULLANIMI ÇUKUROVA ÜNİVERSİTESİ FEN BİLİMLERİ ENSTİTÜSÜ MAKİNE MÜHENDİSLİĞİ ANABİLİM DALI Danışman: Prof. Dr. Melih BAYRAMOĞLU Yıl: 2010, Sayfa: 131 Jüri : Prof. Dr. Melih BAYRAMOĞLU Prof. Dr. Necdet GEREN Doç. Dr. Nihat ÇELİK Otomotiv sanayinde kompozit malzeme kullanımı 1950 li yıllarda başladı. İlk uygulamalarından itibaren kompozit malzemeler hafif, malzeme yorulmasına karşı dayanıklı ve kolaylıkla şekillendirilebilen, metallerin yerine kullanılabilecek alternatif malzeme olduğu ispatlanmıştır. Birçok özelliğinin iyi bilinmesine rağmen metallerden, kompozit malzeme kullanıma geçiş, malzeme karakteristiğindeki belirsizliklerden, üretim ve malzemelerin birleşimi gibi konulardaki belirsizliklerden dolayı tam anlamıyla yapılamamıştır. Bu projede, Ashby malzeme seçim tekniğiyle belirlenen kompozit malzemelerin otomotiv sanayinde kullanımı üzerine birçok örneklendirme yapılarak, kompozit malzemelerin iyi birer alternatif olduğu gösterilmiştir. Özellikle otobüs dış ve iç giydirme malzemelerinde elyaf destekli plastik malzemeler tez içeriğinde kullanılmıştır. Anahtar Kelimeler: Malzeme seçimi, kompozit malzemeler, otobüs parçaları, Ashby tekniği, Elyaf destekli plastikler II ACKNOWLEDGEMENTS I express sincere appreciation to Prof. Dr. Melih Bayramoğlu for his guidance and encouragement throughout the research. The thesis could be much disorganized, without his analytical thoughts and experience in summing up conclusions. I wish to express my special thanks to Mr. İhsan Otabatmaz from TAI (Turkish Aerospace Industries) for introducing me by composite material world. I am thankful to my colleague, Mr. Çetin Doğukaya for his helpful critics and also for providing deeply composite information in his experience. I want to express my special thanks to my manager, Mr. İbrahim Eserce from Temsa Global, for his great support and valuable contribution. Finally, I would like to express my deep gratitude to my family; my mom, dad, sisters who have always supported and confided in me in with endless trust through my education. Great thanks. III CONTENT PAGE ABSTRACT....I ÖZ...II AKNOWLEDGEMENTS...III CONTENT..IV LIST OF TABLES....VII LIST OF FIGURES.VIII 1. INTRODUCTION PREVIOUS STUDIES Composite Materials Manufacturing Processes of Composite Materials Wet Lay-up/Hand Lay-up Resin Transfer Molding Process (RTM) Sheet Molding Compound (SMC) Rotational molding Infusion Process Advantages of Composite Materials Design of Composite Components (Fiber Orientation) Mechanical Properties of Composite Materials Energy Absorption in Various Composite Materials Fatigue Resistance Impact Damage Response in Composite Materials Cost Structure of Composites Material Selection Methods Ashby s Method Dargie s Method Decision Matrices The Pugh Method The Weighted-Properties Method The Pahl & Beitz Decision Matrix 23 IV 2.8. Material Selection Material Selections for Exterior Trimming Parts Bumper Fender Bus Roof Access Door Material Selections for Interior Trimming Parts Sandwich Floor Pedal Box MATERIAL AND METHOD Materials Reinforcements E Glass Fiber Fabric Types and Constructions Fiber Orientation Bulk Materials Unsaturated Polyester Resin Thermoplastic Materials Acrylonitrile Butadiene Styrene (ABS) Method Composites Based Automotive Components Manufacturing Process Selection Criteria Design for Excellence (DFX) Design for Manufacturing and Assembly (DFMA) Test Methods for Composite Materials Tension Test Three-Point Bending Test Heat Deflection Test Barcol Test Burn off Test Burning Behaviour Test Melting Test..51 V UV Resistance Test Heat Cycle Test Thermal Shock Test Heat Aging Test Chemical Resistance Test Abrasion Resistance Test Drop Impact Test Vicat Softening Test Ashby Method and Material Selection Software CES Material Index for Exterior and Interior Trimming Parts RESULTS AND DISCUSSIONS Material Selection Material and Process Selection for Exterior Trimming Parts CES Selector on Limit Stage for Exterior Trimming Parts CES Selector on Graph Stage for Exterior Trimming Parts Test Results for Exterior Trimming Parts Material and Process Selection for Interior Trimming Parts CES Selector on Limit Stage for Interior Trimming Parts CES Selector on Graph Stage for Interior Trimming Parts Test Results for Interior Trimming Parts CONCLUSIONS.103 REFERENCES CURRICULUM VITAE.113 APPENDIX VI LIST OF TABLES PAGE Table 3.1. Mechanical properties of E glass fibers used...33 Table 3.2. Technical properties of Polipol 344-TA and 336 used in closed and open mold applications Table 3.3. ABS sheet material properties according to test results performed..36 Table 3.4. Wear Resistance Test conditions..57 Table 3.5. Evaluated conditions for wear resistance test...57 Table 4.1. Defined design requirements for bumper and fender...65 Table 4.2. Properties of alternative materials for bumper and fender 66 Table 4.3. Mechanical properties used in limit stage for exterior parts..67 Table 4.4. Cost and weight values calculated for bumper by Catia 73 Table 4.5. Cost and weight values calculated for fender by Catia..73 Table 4.6. Three-point bending test results and average values for hand lay-up and RTM.80 Table 4.7. HDT test results and average values for the samples produced by hand lay-up and RTM processes...82 Table 4.8.Tension test results for hand lay-up and RTM samples..83 Table 4.9. Burn off results for hand lay-up and RTM samples..83 Table Design requirements of Headlining.85 Table Properties of alternative materials for Headlining...85 Table Mechanical properties used in limit stage for interior parts 86 Table The weight and cost values for headlining with alternative materials.97 Table Test results for interior trimming material (ABS) 101 VII LIST OF FIGURES PAGE Figure 2.1. Hand lay-up process...8 Figure 2.2. RTM process..9 Figure 2.3. SMC process.10 Figure 2.4. Rotational molding's four basic stations...11 Figure 2.5. Infusion Process...13 Figure 2.6. Fibre orientation- anisotropy...16 Figure 2.7. Specific energy absorption of different materials 17 Figure 3.1. Bumper with exterior and interior appearance 38 Figure 3.2. Fender on the vehicle and backside.38 Figure 3.3. Shimadzu Autography test device Figure 3.4. Dimension of tensile test specimen used in experiment...46 Figure 3.5. Shimadzu Autography test apparatus for three-point bending test...47 Figure 3.6. a. HDT test device, b. Quadrant Engineering Plastic Products test geometry...48 Figure 3.7. Barcol Test device.49 Figure 3.8. Burn off test oven.50 Figure 3.9. The shape and dimensions of the burning behaviour test specimen used in experiment.51 Figure Xenon test device used in weathering test..54 Figure Heat cycle test application sketch...55 Figure Abrasion test device used for interior trimming parts 57 Figure Apparatus with a direct-contact heating unit..59 Figure Relationship among design requirements, material, and process needs 61 Figure Relationship between design flow chart and material 61 Figure Ashby s material selection strategy in four steps...62 Figure Stiff beam length L and minimum mass 63 Figure 4.1. Alternative materials found after entering minimum and maximum density and cost values in limit stage of CES...68 VIII Figure 4.2. Alternative materials obtained after entering minimum and maximum requirements for mechanical properties 68 Figure 4.3. Thermal and electrical properties of candidate materials.69 Figure 4.4. Optical, Processability, Durability values of the candidates 69 Figure 4.5. Durability values of the candidate materials 70 Figure 4.6. Density vs. Young modulus for exterior trimming parts 71 Figure 4.7.Working area on young modulus vs. density graph stage 71 Figure 4.8. Alternative materials on young modulus vs. density graph stage...72 Figure 4.9. Bumpers 3D models drawn by Catia..73 Figure Bumpers 2D drawings drawn by Catia.74 Figure Fender s 3D drawing drawn by Catia 74 Figure Pre-processes are shown on mass range vs. material class 76 Figure Alternative processes on section thickness vs. shape class 77 Figure Pre-processes on Section thickness vs. shape class 78 Figure Roughness values of alternative manufacturing methods..79 Figure Pre-selected manufacturing methods by roughness...79 Figure Stress-strain curves plotted by means of hand lay up specimen for threepoint bending test 80 Figure Stress-strain curves plotted by means of RTM specimens for three-point bending test.81 Figure Limit stage for headlining after entered density and cost...86 Figure Composition and Mechanical properties of Headlining.88 Figure Thermal and optical material properties for headlining.88 Figure Durability results for headlining material selection...89 Figure Durability results for candidate materials..89 Figure Physical attributes shown on limit stage 90 Figure Economic attributes for headlining process selection 91 Figure The values of cost modelling, process characteristic and shape factor..91 Figure Alternative materials on density vs. young modulus for headlining 93 Figure Exact area for alternative headlining materials on young s modulus vs. density.93 IX Figure Alternative materials for interior trimming 95 Figure Alternative materials for headlining on shape factor vs. elongation..96 Figure Pre-selected materials on shape factor vs. elongation 96 Figure Headlining 3D drawings as front and rear drawn by Catia 97 X 1.INTRODUCTION 1. INTRODUCTION The requirement for energy saving in the automotive industry has risen dramatically over the years. One of the options to reduce energy consumption is weight reduction. However, the designer should be aware that in order to reduce the weight, the safety of the car passenger must not be sacrificed. A new invention in technology material was introduced with polymeric based composite materials, which offer high specific stiffness, low weight, corrosion free, and ability to produce complex shapes, high specific strength, and high impact energy absorption. Substitution of polymeric based composite material in automotive components was successfully implemented for fuel and weight reduction. (Suddin, Salit, Ismail, Maleque, Zainuddin, 2004) In its most basic form a composite material is one which is composed of at least two elements working together to produce material properties that are different to the properties of those elements on their own. In practice, most composites consist of a bulk material (the matrix ), and a reinforcement of some kind, added primarily to increase the strength and stiffness of the matrix. This reinforcement is usually in fibre form. Fiber reinforced composite materials have been widely used in various transportation vehicle structures because of their high specific strength, modulus and high damping capability. If composite materials are applied to vehicles, it is expected that not only the weight of the vehicle is decreased but also that noise and vibration are reduced. In addition to that, composites have a very high resistance to fatigue and corrosion (Shin, Lee, 2002) Composite production techniques utilize various types of composite raw materials, including fibers, resins, mats, fabrics, and molding compounds, for the fabrication of composite parts. Each manufacturing technique requires different types of material systems, different processing conditions, and different tools for part fabrication. Each technique has its own advantages and disadvantages in terms of processing, part size, part shapes, part cost, etc. Composite part production success 1 1.INTRODUCTION relies on the correct selection of a manufacturing technique as well as judicious selection of processing parameters (Mazumdar, 2002). Material selection in the automobile industry is an artful balance among market, societal, and corporate demands, and is made during a complex and lengthy product development process. Actual selection of a particular material for a specific application is primarily driven by the trade-off between the material's cost (purchase price and processing costs) and its performance attributes (such as strength, durability, surface finish properties, and flexibility) (Andrea and Brown, 1993) The selection of the correct materials for a design is a key in the process because it is the crucial decision that links computer calculations and lines on an engineering drawing with a working design. Materials, and the manufacturing processes which convert the material into a useful part, underpin all of engineering design. The enormity of the decision task in materials selection is given by the fact that there are well over engineering materials to choose from. There is no method or small number of methods of materials selection that has evolved to a position of prominence. Partly, this is due to the complexity of the comparisons and trade-offs that must be made. Often the properties compared cannot be placed on comparable terms so clear decision can be made. Partly it is due to the fact that little research and scholarly effort have been devoted to the problem (Farag, 1997) In this study, material selection is the key issue to evaluate the alternative materials for automotive industry. Alternative materials for automotive components have been determined by Ashby material and manufacturing selection method that is called as Cambridge Engineering Selector (CES). CES selector has two important stages as limit and graph to assist in material and manufacturing method selection. First of all, in the limit stage, specified material properties obtained from material universe were used to determine alternative materials and manufacturing methods. Limit stage inputs were entered to software as arithmetic values while limit stage outputs were obtained from material and manufacturing list as materials or manufacturing methods. Secondly, graph stage was used to evaluate and compare pre-selected materials and manufacturing methods. At the end of the two stages, preselected materials and manufacturing methods were determined by material and 2 1.INTRODUCTION manufacturing method properties obtained from material and process universe. Before the stages, material selections without CES selector have been performed to define alternative materials and material properties that could be used for exterior and interior components in automotive industry. On the other hand, alternative materials for automotive components as exterior trimming parts; bumper and fender, and as interior trimming part; headlining, have been selected to carry out required material tests including mechanical, physical, thermal, burning behaviour and chemical resistance tests. Test specimens for exterior trimming parts have been obtained from glass fibre reinforced plastic (GFRP) while test specimens for interior trimming part have been obtained from ABS thermoplastic materials. In conclusion, some of comparisons have been performed between materials selected without the aid of the CES selector and materials determined by CES selector including limit and graph stages. The best alternative materials and manufacturing methods were exactly determined by comparisons between limit stage results and graph stage results. The best alternative materials determined by CES selector were evaluated according to the results of the tests that have been made for exterior and interior materials as GFRP and ABS. 3 1.INTRODUCTION 4 2.PREVIOUS STUDIES 2. PREVIOUS STUDIES 2.1. Composite Materials To fully appreciate the role and application of composite materials to a structure, an understanding is required of the component materials themselves and of the ways in which they can be processed. This section looks at basic composite theory, properties of materials used and then the various processing techniques commonly found for the conversion of materials into finished structures (Gurit, 2001) Composite materials are interesting because they have been used for thousands of years in demanding structural applications, and we can expect them to be used indefinitely. Historical composites include cellulose-reinforced lignin (wood), straw reinforced mud (bricks), and steel reinforced concrete. In a general meaning, composite materials for construction, engineering, and other similar applications are formed by combining two or more materials in such a way that the constituents of the composite materials are still distinguishable, and not fully blended. Composite materials currently refer to materials having strong fibers surrounded by a weaker matrix material. Today, the most common man-made composites can be divided into three main groups: Polymer Matrix Composites (PMC s), Metal Matrix Composites (MMC s), Ceramic Matrix Composites (CMC s) (Gurit, 2001) The primary functions of the resin are to transfer stress between the reinforcing fibers, act as a glue to hold the fibers together, and protect the fibers from mechanical and environmental damage. Resins are divided into two major groups known as thermoset and thermoplastic. Thermoset resins are usually liquids or low melting point solids in their initial form. When used to produce finished goods, these thermosetting resins are cured by the use of a catalyst, heat or a combination of the two. Once cured, solid thermoset resins cannot be converted back to their original liquid form. Unlike thermoplastic resins, cured thermosets will not melt and flow but will soften when heated (and lose hardness) and once formed they cannot be 5 2.PREVIOUS STUDIES reshaped. The most common t
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