MARMARA ÜNİVERSİTESİ TEKNOLOJİ FAKÜLTESİ

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1 MARMARA ÜNİVERSİTESİ TEKNOLOJİ FAKÜLTESİ TAŞIT TEKNOLOJİSİ ŞASİ, ÇERÇEVE ve GÖVDE - KAROSER/İ -GİRİŞ- Vehicle Structure Frame, Body, and Chassis Yrd. Doç. Dr. Abdullah DEMİR

2 According to a prediction by British Petroleum (BP), the number of vehicles worldwide will increase from 800 million today to 2 billion in the year 2050 [a]. Global demand for energy will increase by 60 % between now and the year It is estimated that global fossil fuel reserves will last between 40 and 50 years. a) Goeudevert, D.: Die Automobilindustrie ist nicht innovativ. VDI-Nachrichten, Ausgabe D sseldorf, 2006 Bernd (eißing Metin Ersoy (Eds.), Chassis Handbook Fundamentals, Driving Dynamics, Components, Mechatronics, Perspectives, 2011.

3 This statistic shows the number of passenger cars and commercial vehicles in use worldwide from 2006 to In 2012, around 833 million passenger cars and 310 million commercial vehicles were registered worldwide.

4 It can take up to seven years to develop a new vehicle from an initial concept to full series production. Most vehicles remain in series production for approximately seven years. After initial production, passenger vehicles are expected to remain in service for at least ten years and should maintain a high resale value throughout their service life. Engineers and designers must therefore consider a time frame of approximately 25 years starting from the beginning of the concept phase. Bernd (eißing Metin Ersoy (Eds.), Chassis Handbook Fundamentals, Driving Dynamics, Components, Mechatronics, Perspectives, 2011.

5 It should be noted that every automobile is a highly complex machine which consists of 25 to 30 systems, about 500 modules, and more than 50,000 individual parts. Bernd (eißing Metin Ersoy (Eds.), Chassis Handbook Fundamentals, Driving Dynamics, Components, Mechatronics, Perspectives, 2011.

6 Vehicle function levels The V model can be applied to different levels of vehicle development. To facilitate this, the vehicle is divided into different systems, subsystems, modules, etc., until the most basic component level is reached Bernd (eißing Metin Ersoy (Eds.), Chassis Handbook Fundamentals, Driving Dynamics, Components, Mechatronics, Perspectives, 2011.

7 Chassis structures can be separated from the body, as in industrial vehicles and some commercial and off-road vehicles, or they can be integrated, as found in unitized bodies. In this case, auxiliary structures are sometimes applied, to better distribute local loads to the body, supporting suspension mechanisms, engine or power train, transmission and final drive. Chassis structures in these three cases are also called, respectively, frames, underbodies and subframes. G. Genta and L. Morello, The Automotive Chassis, Volume 1: Components Design, 351 Mechanical Engineering Series, 2009 Note: Today, automakers only manufacture about 30 % of each car themselves. The remaining 70 % of the components are purchased from suppliers. Bernd (eißing Metin Ersoy (Eds.), Chassis Handbook Fundamentals, Driving Dynamics, Components, Mechatronics, Perspectives, 2011.

8 Temel Kavramlar

9 The vehicle s main components and sub - systems can be categorically listed as: Power-train, chassis, exterior and interior trims, and the body in white (BiW) or vehicle body - shell. body in white: Beyaz gövde. Bir otomobilin motor vb gibi ana parçaları ile trim donanımı öncesi ana yapısıdır series

10 2013-SL-Class_body_in_white

11 B t n taşıtlar kendilerini ve zerlerindeki y k taşıyan bir gövdeye sahiptir. Kullanım amaçlarına göre farklı olmakla birlikte taşıtların gövdeleri genel olarak iki ana kısımdan oluşur. 1. Şasi 2. Karoseri

12 A typical BiW consists of about stamped pieces, however, only a few main panels affect the overall geometry, fit and finish. These panels are the roof, the trunk (inner, outer, and pan), the hood (inner and outer), the under - body, the wheel - house, the body - side, A and B pillars, the floor pan, the front module (engine cradle, crush zones, shock towers), the quarter panels, and doors (inner, outer). A-pillar: A-direği / s tunu, A- dikmesi. Quarter panel: Arka kelebek panel, çamurluk panel Stamped Preslenmiş parçalar pieces: Figure : The different panels of the vehicle structure Mohammed A. Omar, The Automotive Body Manufacturing Systems and Processes, 2011 John Wiley & Sons Ltd. ISBN:

13 OKUMA PARÇASI: Şasi ve karoseri, otomobilin gövdesini oluşturur. Şasi çerçevesi Şasi çatkısı, aracın b t n parçalarını zerinde taşıyan, motora, karoseriye ve g ç aktarma organlarına desteklik eden bir temeldir. Karoseri ise aracın kaporta ya da gövde diye tabir edilen sac aksamıdır. G n m z araçlarında en genel anlamda iki t r şasi çerçevesi bulunmaktadır. Bunlar ayrı şasi çerçevesi ve birleşik şasi çerçevesidir. Eğer şasi çerçevesi sonradan karoseriye cıvatalarla tutturulacak şekilde yapılmışsa ayrı şasi çerçevesi olarak isimlendirilir. Şasi çerçevesi oldukça katı ve sağlam bir yapıya sahip olmalıdır. G n m z otomobillerinde pek kullanılmamaktadır. Daha çok ağır ticari araçlarda kullanılır. Birleşik şasi çerçevesinde ise; şasi çatkısında parçalar kaynakla tutturulmuştur. Bazı birleştirme yerlerinde kuvvetlendirmeler yapılmak zorundadır. Onun için birleşik karoseri-şasilerin çeşitli böl mlerinde birbirini kuvvetlendiren, t m gövdeyi birlikte destekleyen bir yapı özeliği vardır.

14 Chassis Consists of the vehicle s frame and everything attached to it except the body Includes the tires, wheels, engine, transmission, drive axle assembly, and frame Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co. Chassis Frames The chassis frame is the commercial vehicle's actual load-bearing element. It is designed as a ladder-type frame, consisting of side and cross members. The choice of profiles decides the level of torsional stiffness. Torsionally flexible frames are preferred in medium- and heavy-duty trucks because they enable the suspension to comply better with uneven terrain. Torsionally stiff frames are more suitable for smaller delivery vehicles and vans. Reff: Automotive Handbook

15 Chasis is a French term which denotes the whole vehicle except body in case of heavy vehicles. In case of light vehicles of mono construction it denotes the whole body except additional fitting in the body. Chassis consists of engine, brakes, steering system & wheel mounted on the frame, differential, suspension. ITS PRINCIPAL FUNCTION: To safety carry the maximum load. Holding all components together while driving. Accommodate twisting on even road surface. Endure shock loading. It must absorb engine - driveline torque. «INTRODUCTION TO AUTOMOBILE» Sunumu, SAEINDIA.

16 FRAME Frame is the main part of chassis on which remaining part of chassis are mounted. Frame should be extremely rigid and strong so that it can withstand shocks, twist, stresses and vibrations when vehicle is moving on road. unibody (or monocoque) Strong metal structure that provides a mounting place for other parts of the vehicle Body-over-frame construction chassis parts and body bolt to the frame Unibody (unitized) construction sheet metal body panels are welded together to form the body and frame «INTRODUCTION TO AUTOMOBILE» Sunumu, SAEINDIA.

17 Binek otomobilleri eskiden şasili olarak yapılırlardı. Ancak g n m zde takviye edilmiş karoseri yekpare gövde ile birlikte yapılmaktadırlar. Kendi kendini taşıyan karoseri şasisiz taşıyıcı gövde ve h cre tip karoseri), tabanı kuvvetlendirilmiş bir yapıdadır. Saç gövde gerekli takviyelerle ve şekil mukavemeti yardımı ile dayanıklı hale getirilmektedir Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

18 Ağır kamyonlar ve y k taşıyan taşıtlar şasilidir ve zerinde s r c kabini ile y kleme yapılan kasası vardır. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

19 Karoserinin görevi: Taşıta şekil veren, fonksiyonları yerine getirmesi için ana hacim sağlayan kısmıdır. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006. Made of steel, aluminum, fiberglass, plastic, or composite materials Forms the outside of the vehicle Serves as an attractive covering for the chassis Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

20 Automobile Body Parts Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

21 Kaynak: Toyota

22 Şasi, Çerçeve ve Gövde - Karoser/i

23 Şasinin görevi: İnsan v cudundaki iskelet gibi ana taşıyıcılık görevini yerine getirir. Taşıtın birçok elemanını zerinde taşır. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

24 The Rolling/Driving Chassis Vehicles with ladder-frame chassis configurations (mostly light trucks for the US market) are often preassembled as a rolling chassis including the fuel system, driveline, and other running gear (Figure). This rolling chassis can be assembled by a system supplier and rolled or otherwise transported to the OEM s final assembly line. Rolling chassis (DANA Corp.) [13] Bernd (eißing Metin Ersoy (Eds.), Chassis Handbook Fundamentals, Driving Dynamics, Components, Mechatronics, Perspectives, 2011.

25 Merdiven Tipi Şasi (Paralel Kollu Şasi): Kamyon ve otob slerde yaygın olarak kullanılan şasi tipidir. Paralel iki kol ve bu iki kola bağlanmış kuşaklardan oluşur. Kollar genelde U, kare, dikdörtgen ve daire kesitli olarak preste yapılırlar. Kuşaklar ve st yapı, kaynak, perçin ve cıvata ile şasi kollarına bağlanır. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

26 The ladder frame is the simplest and oldest of all designs. It consists merely of two symmetrical rails, or This design offers good beam resistance because of its continuous rails from front to rear poor resistance to torsion «INTRODUCTION TO AUTOMOBILE» Sunumu, SAEINDIA.

27 Paralel Kollu Şasi (Merdiven Tipi Şasi) Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/03/2006. Kaynak: VW, Otomobil Teknolojisinin Temelleri

28 Çapraz Kollu (X Tipi) Şasi: Oldukça hafif bir yapısı vardır. Daha çok kamyonetlerde tercih edilir. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

29 Tek Kollu (Platform) Şasi: Ortada tek bir kol ve buna bağlanmış kuşaklar, bazen de taban sacı ile bir b t n olarak yapılırlar. Otomobillerde tercih edilir. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

30 Çatal Kollu Şasi: Taşıt motorunun bağlanmasına ve destek oluşturmasına elverişli bir şasi tipidir. Kamyonetlerde ve otomobillerde tercih edilir. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

31 Gövde Tipleri Body Types

32 Vehicle Type Vehicle Classification Body Style Power Train Suspension Passenger Car 2D/3D/4D/5D UniBody Engine: L Trans: 5spd/Auto Driveline: FWD MPV 4D/5D UniBody Engine: > 2.0L Trans: Auto Driveline: FWD SUV Luxury Car 5D Unibody or Body on Frame 4D Unibody or Body on Frame Engine: L Trans: Auto Driveline: FWD/RWD/AWD Engine: >2.5 L Trans: Auto Driveline: FWD/RWD Sports Car 2D/3D Unibody Engine: >3.5 L Trans: 5Spd Driveline: RWD Pickup Truck 2D/4D Body on Frame Engine: >2.5 L Trans: Auto Driveline: RWD/AWD Commercial Truck 2D Body on Frame Fundamentals of Vehicle Design; Dr. Shirish P Patil & Dr. Kamarul Tawi Engine: >5 L Trans: Auto Driveline: RWD Front: McPherson Rear: Multi-link Front: McPherson Rear: Multi-link Front: McPherson/SLA Rear: Multi-link/Solid Axle Front: SLA Rear: Multi-link Front: McPherson Rear: Multi-link Front: SLA Rear: Solid Axle Front: SLA Rear: Solid Axle

33 The purpose of body design is to achieve the following: Aesthetics: to provide a pleasing overall appearance, surface quality and consistent details. Structural function: to support the weight of the transported passengers and load as well as the mechanical parts required for vehicle propulsion, control and other system functions, so withstanding mechanical stresses from multiple sources. Ergonomy and roominess: to supply easy access and adequate room for the driver, passengers and transported goods. Safety: to ensure integrity of passenger compartment in the event of a crash, while absorbing the impact energy as well as to reduce injuries to vulnerable road users (pedestrians, wheelers), in case of collision. Aerodynamics: to minimize drag due to air impact; to control air flow effects on tyre-road contact and vehicle stability. Insulation: to minimize noise, vibration and thermal transmission, generated by body walls, by lack of sealing between compartment and movable parts and by thermal radiation from the surfaces of passengers compartment. Visibility: to provide the highest possible day and night visibility on the environment and to host the lighting devices in the most effective way. Lorenzo Morello, Lorenzo Rosti Rossini, Giuseppe Pia, Andrea Tonoli, The Automotive Body, Volume I: Components Design, e-isbn

34 The interior and exterior trims compose the front and rear ends, the door system, and the cockpit trim. Finally, the body in white is made up of the closures (doors, hood, tail-gate) and the frame, see Figure 1 ). Mohammed A. Omar, The Automotive Body Manufacturing Systems and Processes, 2011 John Wiley & Sons Ltd. ISBN:

35 emmesei.com

36 Body Types Automobiles are available in several body types, including: sedan hardtop convertible hatchback station wagon minivan sport-utility vehicle Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

37 Sedan A sedan is a car with a four-door body configuration and a conventional trunk or a sloping back with a hinged rear cargo hatch that opens upward. Sedan is the most common body style that are cars with four or more seats and a fixed roof that is full-height up to the rear window. Sedans can have two or four doors. Uses center body pillars, or B pillars, between the front and rear doors. A hardtop does not use B pillars. Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

38 Convertible A convertible is a car with a removable or retractable top. Uses a vinyl or cloth top that can be raised and lowered Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

39 Hatchback The large rear door allows easy access when hauling items Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

40 Station Wagon A wagon is a car with an extended body and a roofline that extends past the rear doors. Station wagon or wagon is a car with a full-height body all the way to the rear; the load-carrying space created is accessed via a rear door or doors. Provides a large rear interior compartment Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

41 Minivan Has a higher roofline for more headroom and cargo space A minivan/van is a vehicle with a box-shaped body enclosing a large cargo or passenger area. The identified gross weight of a van is less than lb 4,500 kg. Vans can be identifiable by their enclosed cargo or passenger area, short hood, and box shape. Vans can be divided into mini van, small van, midsize van, full-size van, and large van. The van subdivision has the same specifications as SUV subdivisions. Minivans are boxy wagon cars usually containing three rows of seats, with a capacity of six or more passengers and extra luggage space. Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

42 Sport-Utility Vehicle Provides the comfort of a passenger car, the interior space of a station wagon, and the durability of a truck An MPV (multi-purpose vehicle) is designed as large cars or small buses having off-road capability and easy loading of goods. However, the idea for a car with a multi-purpose application can be seen in other classes, especially SUVs. Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co. An SUV (sport utility vehicle) is a vehicle with off-road capability. SUV is designed for carrying ten or fewer persons, and generally considered a multi-purpose vehicle. Most SUVs are four-wheeldrive with and increased ground clearance. The SUV is also known as 4- by-4, 4WD, 4 4 or 4x4. SUVs can be divided into mini, small, midsize, fullsize, and large SUV.

43 Tam Taşıyıcı Karoseri: G n m zde binek otomobiller şasisiz olarak imal edilmektedirler. Gövde kendi kendini taşıyan bir formda dizayn edilmektedir. Genellikle karoseri gövdesi hücre tip dediğimiz gövdedir. Bilgisayarlar yardımı ile orijinal yapının ve istenilen bölge veya parçaların tek tek deformasyon ve gerilmeleri hesaplanabilir. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

44 Hücre Tipi Karoseri: Taşıt gövdesi ayrı h crelerden oluşur. Yolcu böl m taşıtın ön ve arkasına göre korunmaya alınmıştır. Çarpışma anında ön ve arka h creler daha elastik yapıldıkları için yolculara gelecek darbe minimuma indirilmiştir. Binek otomobillerde genellikle uygulanan bir gövde tipidir. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

45 Karma Tip Karoseri: Şasi ve karoserinin bir nevi kombinasyonundan meydana gelmiştir. Taşıt, bir platform şasi veya çatal şasi ile gövde saçının kaynakla veya cıvata ile birleştirilmesinden oluşur. Otomobil ve otob slerde uygulaması vardır. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

46 Kaynak: VW, Otomobil Teknolojisinin Temelleri

47 Kaynak: VW, Otomobil Teknolojisinin Temelleri

48 Audi Space Frame When it introduced the first A8 in 1994, Audi had not only developed the radically new ASF design and put it into series production, it had also developed all of the steps required for its production. The launch was preceded by a development process lasting 12 years. Since this time Audi has built on its competitive edge step by step. The arc spans three generations of the A8 and also includes the A2 along with its legendary three-liter version, the A2 1.2 TDI. By the end of 2010 alone, the company had produced some 550,000 vehicles with the ASF body far more than any other manufacturer in the world. ASF olarak bilinen Audi Space Frame (Audi Uzay Kafesi), hafif gövde yapısı sayesinde daha fazla performans ve daha d ş k yakıt t ketimi gibi avantajlar sunmaktadır.

49 Şasisiz Otobüs Gövdeleri: Otob s imalinde şasisiz gövdeye örnek olarak gösterilen iki ana grup vardır. Bunlar: 1. Platform takviyeli otobüs gövdesi 2. Tam taşıyıcı otobüs gövdesi Her iki yapı tipide şasili tipe nazaran hafiftir. Taşıt ağırlığında azalma tam taşıyıcı otob s gövdesinde daha fazladır. Ağırlık azalması şasinin çıkması ile %8 civarında olur. Ancak bunun bir kısmı mukavemet arttırmak amacı ile tekrar kullanılır. Taşıtın boş ağırlığı ne kadar az ise işletme şartları da o oranda ekonomik olur. Kaynak: Şase ve Karoseri Sunumu, TÜVTURK, 08/0 / 006.

50 Ek Okuma ve İnceleme Bölümü

51 Moreover, the body must satisfy a series of prerequisites: high reliability (to maintain design functions vehicle life along), low cost (to minimize production investment, process and material cost), high material recyclability (by rapid disassembling and straightforward division of heterogeneous materials). These functions ere required by the completely assembled body and are achieved through the individual contribution of body components and several body systems. Fig. 1: Common body and chassis configurations. Lorenzo Morello, Lorenzo Rosti Rossini, Giuseppe Pia, Andrea Tonoli, The Automotive Body, Volume I: Components Design, e-isbn

52 A) Unitized body or unibody, in which the chassis parts cannot be physically removed from the upper body parts. In this case, suspensions and other mechanical parts are directly fitted (using brackets) to body frame. The main advantage of such solution is relatively low weight, while the main disadvantage is a lower dimensional precision of suspension attachment, due to body tolerance and the lower filtering performance of suspension fittings, reducing the insulation of vibrations due to road-wheel excitation. B) Body on frame, where the chassis frame is connected to upper body frame by bolts with or without the inter-position of rubber bushes. Such a solution offers the main advantage of allowing the adoption of one chassis for different body shapes, providing benefits in terms of mechanical parts standardization and simplification of the assembly process of a mechanical chassis, before being matched to the upper body. This kind of solution is commonly used for cargo vehicles, off-road and SUV. The main disadvantage is the increased weight with respect to configuration A). Farklı ifade biçimleri: Unitized body: Unibody (or monocoque) Body on frame: Body-over-frame Lorenzo Morello, Lorenzo Rosti Rossini, Giuseppe Pia, Andrea Tonoli, The Automotive Body, Volume I: Components Design, e-isbn

53 Unibody Construction The frame is an integral part of the body Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

54 Body-over-Frame Construction The body bolts to a thick steel frame Russell Krick, Modern Automotive Technology Sunumu, The Goodheart-Willcox Co.

55 The frame can be of a uni - body design (Figure 1.1 (a) uni - body), a body - on - frame (Figure 1.1 (b)), or a space - frame (Figure 1.1 (c)). The uni-body design features stamped panels, while the space - frame is made up of extrusions and cast parts. The BiW closures are selected based on the vehicle s constituent material dent - resistance properties (i.e. yield strength) while the frame is designed to provide specific torsional and bending stiffness. Figure 1.1: Top left: (a) a uni - body design, top, right: (b) truck platform; and bottom right: (c) space - frame design Mohammed A. Omar, The Automotive Body Manufacturing Systems and Processes, 2011 John Wiley & Sons Ltd. ISBN:

56 Reading text: Unitized (self-supporting) body (Standard design) The conventional unitized (self-supporting) body is built up of hollow sheet-steel components onto which body panels are welded by welding robots or in multispot welding units. Individual parts can also be glued in position. Depending upon vehicle type, roughly 5000 spot welds must be made along a total flange length of m. The flange widths are mm. Other parts (front fenders, doors, hood and luggagecompartment lid) are bolted to the supporting structure of the body. Other types of body construction include frame and sandwich designs. Reff: Automotive Handbook

57 C) Body with ancillary subframes, for powertrain and suspension systems; connections between the subframe and the body can be either rigid or through elastic bushes. The main advantages are modularity and the division of the assembly process between parallel lines, enabling components to be mounted on the sub-frames. The resulting sub-assemblies can be tested before integration with main body. Moreover, the relative ease in which elastic and damping devices between subframe and body can be inserted, provide an improved insulation from noise and vibration. Again, the main disadvantage is increased weight, but to a lower extent than configuration B). D) Dual frame body, in which body and chassis are separate and connected through elastic and damping bushes. In this configuration, the structural, safety, propulsion and driving functions are concentrated and optimized in the chassis, with priority to front and rear crash absorption, torsional stiffness and resistance to stress induced through the suspension and powertrain stiff and precise, since the filtering of road-surface induced excitation is achieved by incorporating elastic connections between chassis and body. The weight of upper body can be reduced, since the structural task is limited to its own inertial stresses and to those induced by transported components, people and load. The same chassis can also be adopted by different bodies of similar inertia properties. Although the increase of chassis weight remains a disadvantage, it is partially counterbalanced by the reduction in the weight of upper body. Lorenzo Morello, Lorenzo Rosti Rossini, Giuseppe Pia, Andrea Tonoli, The Automotive Body, Volume I: Components Design, e-isbn

58 Ladder Chassis: Ladder chassis is considered to be one of the oldest forms of automotive chassis or automobile chassis that is still used by most of the SUVs till today. As its name connotes, ladder chassis resembles a shape of a ladder having two longitudinal rails inter linked by several lateral and cross braces. Monocoque Chassis: Monocoque Chassis is a one-piece structure that prescribes the overall shape of a vehicle. This type of automotive chassis is manufactured by welding floor pan and other pieces together. Since monocoque chassis is cost effective and suitable for robotized production, most of the vehicles today make use of steel plated monocoque chassis. Backbone Chassis: Backbone chassis has a rectangular tube like backbone, usually made up of glass fibre that is used for joining front and rear axle together. This type of automotive chassis or automobile chassis is strong and powerful enough to provide support smaller sports car. Backbone chassis is easy to make and cost effective. M. Ravi Chandra1, S. Sreenivasulu2, Syed Altaf Hussain3; Modeling and Structural analysis of heavy vehicle chassis made of polymeric composite material by three different cross sections; International Journal of Modern Engineering Research (IJMER) Vol.2, Issue.4, July-Aug pp ISSN:

59 KISA KISA KISA

60 (A) Unibody construction welds major body panels together to form the frame for attaching the engine, drivetrain, suspension, and other parts. This type of construction is commonly used on cars. (B) With body-over-frame construction, a thick gauge steel frame provides the foundation for holding other parts. This type of construction is commonly used on large trucks and SUVs. Figure 1: Two very different methods used to construct modern vehicles: unibody and bodyover-frame construction Chapter 9 Vehicle Construction, Thomson

61 Figure 2: Note the space frame construction. Composite (plastic) panels fasten to a metal inner body structure. Composite panels can be made flexible to resist door dings and small dents. Chapter 9 Vehicle Construction, Thomson

62 Figure 3: This top view of unibody construction shows how structural members are added to support the engine suspension and other mechanical systems. Chapter 9 Vehicle Construction, Thomson

63 Figure 4: Doors normally have strong steel beams under the door skin to protect people during side impact collisions. Chapter 9 Vehicle Construction, Thomson

64 Summary Vehicle classification relates to construction, size, shape, number of doors, type of roof, etc. Three main types of frame construction Body-over-frame, unibody, and space frame Vehicle commonly divided into 3 body sections Front section, or nose section Center section, or midsection Rear section, tail section, or rear clip Vehicle sizes: compact, intermediate, full size Chapter 9 Vehicle Construction, Thomson