sasi-ve-karoseri.pdf

MARMARA NVERSTES TEKNOLOJ FAKLTES

TAIT TEKNOLOJS

HAZIRLAYAN:

Yrd. Do. Dr. Abdullah DEMR

Temel Kavramlar

The vehicles 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.

Btn tatlar kendilerini ve zerlerindeki yk tayan bir gvdeye sahiptir. Kullanm amalarna gre farkl olmakla birlikte tatlarn gvdeleri genel olarak iki ana ksmdan oluur. 1. asi 2. Karoseri

body in white: Beyaz gvde. Bir otomobilin motor vb gibi ana paralar ile trim donanm ncesi ana yaps

Figure : The different panels of the vehicle structure

A typical BiW consists of about 300 400 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).

Mohammed A. Omar, The Automotive Body Manufacturing Systems and Processes, 2011 John Wiley & Sons Ltd. ISBN: 978-0-470-97633-3

A-pillar: A-direi / stunu, A-dikmesi. Quarter panel: Arka kelebek panel, amurluk panel

Stamped pieces: Preslenmi paralar

OKUMA PARASI: asi ve karoseri, otomobilin gvdesini oluturur. asi erevesi (asi atks), aracn btn paralarn zerinde tayan, motora karoseriye ve g aktarma organlarna desteklik eden bir temeldir. Karoseri ise aracn kaporta ya da gvde diye tabir edilen sac aksamdr. Gnmz aralarnda en genel anlamda iki tr asi erevesi bulunmaktadr. Bunlar ayr asi erevesi ve birleik asi erevesidir. Eer asi erevesi sonradan karoseriye cvatalarla tutturulacak ekilde yaplmsa ayr asi erevesi olarak isimlendirilir. asi erevesi olduka kat ve salam bir yapya sahip olmaldr. Gnmz otomobillerinde pek kullanlmamaktadr. Daha ok ar ticari aralarda kullanlr. Birleik asi erevesinde ise; asi atksnda paralar kaynakla tutturulmutur. Baz birletirme yerlerinde kuvvetlendirmeler yaplmak zorundadr. Onun iin birleik karoseri-asilerin eitli blmlerinde birbirini kuvvetlendiren, tm gvdeyi birlikte destekleyen bir yap zelii vardr.

Binek otolar eskiden asili olarak yaplrlard. Ancak gnmzde takviye edilmi karoseri yekpare gvde ile birlikte yaplmaktadrlar. Kendi kendini tayan karoseri (asisiz tayc gvde ve hcre tip karoseri), taban kuvvetlendirilmi bir yapdadr. Sa gvde gerekli takviyelerle ve ekil mukavemeti yardm ile dayankl hale getirilmektedir

Kaynak: ase ve Karoseri Sunumu, TVTURK, 08/03/2006.

Ar kamyonlar ve yk tayan tatlar asilidir ve zerinde src kabini ile ykleme yaplan kasas vardr.


Chassis

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

Consists of the vehicles frame and everything attached to it except the body

Includes the tires, wheels, engine, transmission, drive axle assembly, and frame

INTRODUCTION TO AUTOMOBILE Sunumu, SAEINDIA.

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.

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.


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 unibody (or monocoque)

Karoserinin grevi: Tata ekil veren, fonksiyonlar yerine getirmesi iin ana hacim salayan ksmdr. Kaynak: ase ve Karoseri Sunumu, TVTURK, 08/03/2006.

Made of steel, aluminum, fiberglass, plastic, or composite materials

Forms the outside of the vehicle

Serves as an attractive covering for the chassis


Automobile Body Parts


Kaynak: Toyota

asi, ereve ve Gvde - Karoser/i

Lorenzo Morello, Lorenzo Rosti Rossini, Giuseppe Pia, Andrea Tonoli, The Automotive Body, Volume I: Components Design, e-ISBN 978-94-007-0513-5

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.


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 ).

asinin grevi: nsan vcudundaki iskelet gibi ana tayclk grevini yerine getirir. Tatn birok elemann zerinde tar.



Paralel Kollu asi: Kamyon ve otobslerde yaygn olarak kullanlan asi tipidir. Paralel iki kol ve bu iki kola balanm kuaklardan oluur. Kollar genelde U, kare, dikdrtgen ve daire kesitli olarak preste yaplrlar. Kuaklar ve st yap, kaynak, perin ve cvata ile asi kollarna balanr.

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



Paralel Kollu asi Merdiven Tipi asi

Kaynak: VW, Otomobil Teknolojisinin Temelleri


apraz Kollu (X Tipi) asi: Olduka hafif bir yaps vardr. Daha ok kamyonetlerde tercih edilir.


Tek Kollu (Platform) asi: Ortada tek bir kol ve buna balanm kuaklar, bazen de taban sac ile bir btn olarak yaplrlar. Otomobillerde tercih edilir.


atal Kollu asi: Tat motorunun balanmasna ve destek oluturmasna elverili bir asi tipidir. Kamyonetlerde ve otomobillerde tercih edilir.


Tam Tayc Karoseri: Gnmzde binek otomobiller asisiz olarak imal edilmektedirler. Gvde kendi kendini tayan bir formda dizayn edilmektedir. Genellikle karoseri gvdesi hcre tip dediimiz gvdedir. Bilgisayarlar yardm ile orijinal yapnn ve istenilen blge veya paralarn tek tek deformasyon ve gerilmeleri hesaplanabilir.


Hcre Tipi Karoseri: Tat gvdesi ayr hcrelerden oluur. Yolcu blm tatn n ve arkasna gre korunmaya alnmtr. arpma annda n ve arka hcreler daha elastik yapldklar iin yolculara gelecek darbe minimuma indirilmitir. Binek otomobillerde genellikle uygulanan bir gvde tipidir.


Karma Tip Karoseri: asi ve karoserinin bir nevi kombinasyonundan meydana gelmitir. Tat, bir platform asi veya atal asi ile gvde sann kaynakla veya cvata ile birletirilmesinden oluur. Otomobil ve otobslerde uygulamas vardr.


asisiz Otobs Gvdeleri: Otobs imalinde asisiz gvdeye rnek olarak gsterilen iki ana grup vardr. Bunlar: 1. Platform takviyeli otobs gvdesi 2. Tam tayc otobs gvdesi Her iki yap tipide asili tipe nazaran hafiftir. Tat arlnda azalma tam tayc otobs gvdesinde daha fazladr. Arlk azalmas asinin kmas ile %8 civarnda olur. Ancak bunun bir ksm mukavemet arttrmak amac ile tekrar kullanlr. Tatn bo arl ne kadar az ise iletme artlar da o oranda ekonomik olur. Bu nedenle tatn ar olmas istenmez.

Gvde Tipleri Body Types

Body Types


Automobiles are available in several body types, including: sedan hardtop convertible hatchback station wagon minivan sport-utility vehicle

Sedan

Uses center body pillars, or B pillars, between the front and rear doors. A hardtop does not use B pillars.


A sedan is a car with a four-door body conguration 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 xed roof that is full-height up to the rear window. Sedans can have two or four doors.

Convertible

Uses a vinyl or cloth top that can be raised and lowered


A convertible is a car with a removable or retractable top.

Hatchback

The large rear door allows easy access when hauling items


Station Wagon

Provides a large rear interior compartment


A wagon is a car with an extended body and a rooine 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.

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 identied gross weight of a van is less than 10.000 lb 4,500 kg. Vans can be identiable 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 specications 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.

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 o-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.

An SUV (sport utility vehicle) is a vehicle with o-road capability. SUV is designed for carrying ten or fewer persons, and generally considered a multi-purpose vehicle. Most SUVs are four-wheel-drive 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, full-size, and large SUV.

Ek Okuma ve nceleme Blm


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.


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).

Unibody Construction

The frame is an integral part of the body


Body-over-Frame Construction

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

Figure 1.1: Top left: (a) a uni - body design, top, right: (b) truck platform; and bottom right: (c) space - frame design

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 vehicles constituent material dent - resistance properties (i.e. yield strength) while the frame is designed to provide specific torsional and bending stiffness.


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 multi-spot 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 120...200 m. The flange widths are 10...18 mm. Other parts (front fenders, doors, hood and luggage-compartment lid) are bolted to the supporting structure of the body. Other types of body construction include frame and sandwich designs. Reff: Automotive Handbook


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.


Referring to body missions previously listed, the different configurations result in variations of upper body contribution for just a limited number of functions, in which the characteristics of body connection with the chassis is highly relevant: structural function, insulation and isolation, safety and, partially, aerodynamics (due to floor contribution). The remaining functions are not directly affected . Focusing on the most common body configuration (C), through the example of a 2 box mass production body in white with spot welded steel stamped sheets, it is appropriate to consider the main stamped parts and follow a typical assembling process step-by-step, to gain a deeper understanding of the process used to manufacture the body, widely applied today.

Kaynak: VW, Otomobil Teknolojisinin Temelleri

asinin alma Koullar

ve Traversler

http://www.roversnorth.com/Land-Rover-Parts/77

asinin alma Koullar

Chassis Operating Conditions The design of an automobile chassis requires prior understanding of the kind of conditions the chassis is likely to face on the road. The chassis generally experiences four major loading situations, that include, vertical bending, longitudinal torsion, lateral bending, and horizontal lozenging.

http://what-when-how.com/automobile/chassis-frame-sections-automobile/

asinin alma Koullar

Vertical Bending: Considering a chassis frame is supported at its ends by the wheel axles and a weight equivalent to the vehicles equipment, passengers and luggage is concentrated around the middle of its wheelbase, then the side-members are subjected to vertical bending causing them to sag in the central region.


asinin alma Koullar

Longitudinal Torsion: When diagonally opposite front and rear road-wheels roll over bumps simultaneously, the two ends of the chassis are twisted in opposite directions so that both the side and the cross-members are subjected to longitudinal torsion (Fig. 1), which distorts the chassis.

Fig. 1: Longitudinal torsion. http://what-when-how.com/automobile/chassis-frame-sections-automobile/

asinin alma Koullar

Lateral Bending: The chassis is exposed to lateral (side) force that may be due to the camber of the road, side wind, centrifugal force while turning a corner, or collision with some object. The adhesion reaction of the road-wheel tyres opposes these lateral forces. As a net result a bending moment (Fig. 2) acts on the chassis side members so that the chassis frame tends to bow in the direction of the force.

Fig. 2. Lateral bending


asinin alma Koullar

Horizontal Lozenging: A chassis frame if driven forward or backwards is continuously subjected to wheel impact with road obstacles such as pot-holes, road joints, surface humps, and curbs while other wheels produce the propelling thrust. These conditions cause the rectangular chassis frame to distort to a paral-lelogram shape, known as lozenging (Fig. 3).

Fig. 3: Lozenging http://what-when-how.com/automobile/chassis-frame-sections-automobile/

Murat Ereke, Kubilay Yay, iftkatl Otobs Gvdesinin Bilgisayar Destekli Gerilme Analizi

Bir tata etki eden kuvvetler, tat cinsine gre deiiklik arz etmekle birlikte temelde iki ana gruba ayrlrlar. Bunlar, Statik ve Tekrarl Dinamik kuvvetlerdir. Tatn maruz kald kuvvetlerin bykl ne kadar nemliyse kuvvetlerin tekrar da en az o kadar nemlidir. Zira, kuvvetleri periyodik olarak deitirmek ve deiim saysn yeter derecede arttrmakla bir malzemeyi statik snrlarn ok altnda da harap etmek mmkndr. Statik kuvvetler deiken olmayan kuvvetler ile aracn mr boyunca en fazla 5x103 defa tekrarlanan kuvvetlerdir. Statik kuvvetler, tatn kendi z arl ve yk, fren ve kalk kuvvetleri, viraj kuvvetleri, burulma kuvvetleri, mnferit darbe kuvvetleri, ekici ile rmork aras bindirme kuvvetleri olarak saylabilir. Tekrarl dinamik kuvvetler ise 25x106 tekrar saysndan balayan, yol przll, lastik evresinin dzgnszl gibi sebeplerden dolay ortaya kar.

TAITA ETK EDEN STATK KUVVETLER


Tat gvdesi yapsal analizinde, iletme artlarndan doan kuvvetlere kar dayankllk temel hedeflerden biridir. Hedef, arlk asndan uygun, yeteri kadar mukavim bir yap (hafif yap) elde etmek, malzeme ve enerji tasarrufu salamaktr. Karoserinin karmak yaps gerei, iletme artlarndan doan zorlanma sonucu oluacak gerilmelerin hangi younlukta ve hangi iddette olacann kestirilmesi byk zorluk arz eder. Gerilme ylmalarnn olduu blgeler kritik blgelerdir. Bu blgelerdeki kesitlerin doru tasarm iin gerilmelerin iddetleri bilinmek zorundadr. Deformasyonlarn ve gerilme ylmalarnn tespitinde gvdenin sonlu eleman yntemiyle modellenerek bilgisayar ortamnda analizi modern tasarm tekniklerinin banda gelmektedir.



Tatn Kendi z Arl ve Yk: Tatn dz ve yatay bir zeminde durduu farz edilirse, ekildeki kuvvetlerin etkisi altnda kalacaktr. G arl, tatn z arln ve yk birlikte ifade etmektedir. n ve arka akslar birer lastikli olan tatlar binek otomobilleri, hafif kamyonlar ve hafif rmorklardr. n ve arka aks ykleri arasnda fazla fark olumaz, yani hemen hemen birbirine eit kabul edilebilir.


Fren Kuvveti Fren kuvvetleri tat fren yapt zaman ortaya karlar. Dz yolda ideal fren kuvveti dalm ile elde edilecek fren ivmesi ortalama 4,5 m/s2dir. Balangta bir anlk maksimum deere ulaan fren ivmesi dz ve kuru bir asfalt yolda 8 m/s2ye kadar kar. Fren hesaplarnda fren yolu boyunca muteber olan ortalama ivmedir. / Ref: Murat Ereke, Kubilay Yay, iftkatl Otobs Gvdesinin Bilgisayar Destekli Gerilme Analizi


Viraj kuvveti Tat viraja girdii zaman, merkezka kuvvetin etkisi altndadr. Kuvvetin yn dar doru olduu iin asi d putreline gelen yk artmaktadr. Viraj kuvveti hesaplanrken ekildeki gibi arlk merkezinin yerden yksekliinin (h), tat arlnn (G), viraj ivmesinin (a) ve iki tekerlek arasndaki mesafenin bilinmesi yeterlidir. / Ref: Murat Ereke, Kubilay Yay, iftkatl Otobs Gvdesinin Bilgisayar Destekli Gerilme Analizi



Darbe Kuvveti Tekerlein tek bir sete arpma veya ukura dmesinden meydana gelen darbeden doan dey yk, kamyonlarda ykl arln %100, otobslerde ise %50si olarak kabul edilir.



Burulma Kuvveti Bir tatn n tekerleklerinden biri bir tmsek veya bir engebenin zerine karsa o tekerlein dinamik tekerlek yk artmaktadr. Sa ve sol tekerleklerin dinamik tekerlek yklerinin fark tat uzunlamasna eksen boyunca burulmaya zorlamaktadr. Tekerlek yklerinin birbirlerine gre fark ve dolays ile burulma momentinin bykl engebenin ykseklii, tekerlek iz geniliinin bykl, lastiklerin ve yaylarn katl ve tat gvdesinin katlna baldr. Tatlarn burulma momenti engebe yksekliine bal olarak artmakta olup, her tat iin alabilecek bir engebe ykseklii snr vardr. Tekerlek iz genilii ne kadar byk olursa, belli bir engebe ykseklii iin meydana gelen burulma momenti o kadar kk olur. Lastik ve yaylarn yumuakl ise, belli bir engel yksekliinde gvdenin daha az dnp dnmemesinde rol oynamaktadr. Sspansiyon sistemi ne kadar yumuak olursa, burulma o kadar az olur. Tat gvdesinin katl veya elastiklii de burulma momenti ile ilgili olup gvde elastik olduu lde moment dmektedir.



Burulma Kuvveti (dvm.) Bir tat gvdesinin boyutlandrlmasnda deiik zorlayc kuvvetleri dikkate almak gerekir. Her eyden nce statik kuvvetler altnda gvdede veya aside kalc deformasyonlardan kanmak arttr. Bir otobs gvdesi iin ilk yaklam hesabnda tatn z arl ve yk + %30 mnferit darbe kuvveti + %50 burulma kuvveti kullanlabilir.

Otobs gvdelerinde kutu profilden oluan kiriler kullanlr. Malzemesi ise St 37dir. Literatre gre [1,2], otobs gvdesi imalatnda kullanlan bu malzeme iin ortalama gerilme snr (n gerilme) m= 9 kg/mm2 ve genlik gerilmesi snr g= 8 kg/mm2 deerleri alnmaldr. Akma gerilmesi de F iin de 24 kg/mm2 deerinde alnabilir.


Chassis-frame Design

Side-member And Cross-member

Chassis Frame Sections During movement of a vehicle over normal road surfaces, the chassis frame, is subjected to both bending and torsional distortion as discussed in the previous section. Under such running conditions, the various chassis-member cross-section shapes, which find application, include. Solid round or rectangular cross-sections, Enclosed thin-wall hollow round or rectangular box-sections, Open thin-wall rectangular channelling such as C, T, or top-hat

sections. Side-member Bending Resistance: The chassis side-members, which span the wheelbase between the front and rear axles must be able to take the maximum of the sprung weight. The sprung weight is the weight of the part of the vehicle supported by the suspension system. The binding stiffness of these members must resist their natural tendency to sag. The use of either pressed-out open-channel sections or enclosed thin-wall hollow round or rectangular box-sections can provide the maximum possible bending stiffness of chassis members relative to their weight.


Square bar 1.0 Round bar 0.95 Round hollow tube 4.3 Rectangular C-channel 6.5 Square hollow section 7.2

Chassis Frame Sections A comparison of the bending stiffnesses of different cross-sections having the same cross-sectional area and wall thickness is presented in Fig. A to F. Considering a stiffness of 1 for the solid square section, the relative bending stiffnesses for other sections are, Practically, a 4 mm thick C-section channel having a ratio of channel web depth to flange width of about 3:1 are used as chassis side-members. This provides a bending resistance of 15 times greater than that for a solid square section with the same cross sectional area. For heavy-duty applications, two C-section channels may be placed back to back to form a rigid load-supporting member of I-section (Fig. H). To provide additional strength and support for an existing chassis over a highly loaded region (for example, part of the side-member spanning a rear tandem-axle suspension), the side-members may have a double-section channel. This second skin is known as a flitch frame or plate.

Side-and Cross-member Torsional Resistance. The open-channel sections exhibit excellent resistance to bending, but have very little resistance to twist. Therefore, both side and cross-members of the chassis must be designed to resist torsional distortion along their length. Figure C to F illustrates the relative torsional stiffness between open-channel sections and closed thin-wall box-sections. Comparisons firstly between the open and closed circular sections and secondly between the rectangular sections are made, considering the open section has a resistance of 1 in each case.

Longitudinal split tube = 1.0 Enclosed hollow tube = 62.0 Open rectangular C-channel = 1.0 Closed rectangular box-section = 105.0


Fig.: Chassis-member sections. A. A. Square solid bar B. B. Round solid bar C. Circular tube with

longitudinal slit D. Circular closed tube E. C-section F. Rectangular box section G. Top-hat-section H. I-section I. Channel flitch plate


This clearly explains the advantages of using channel sections over the hollow tube due to high torsional stiffness. The chassis frame, however, is not designed for complete rigidity, but for the combination of both strength and flexibility to some degree.

asi ve Karoser Malzemeleri


asi Malzemeleri Karoseri Malzemeleri St 42 yaygn olarak kullanlan bir malzemedir. Kaynaa ok iyi gelir, pres altnda rahat ekil verilebilir. St-50, St-60, St-70 elikleri de kullanlr. Bu malzemeler daha ok kaynak kullanlmayan perin balantl asiler iin uygundur. Kaynaa gelmezler nk karbon miktarlar yksektir. nce sa dediimiz 3 mm altndaki sa malzeme kullanlr. Karoseri sa olarak kullanlan elik St-10dur. Ayrca hafif metal kullanm da mevcuttur. Hafif metalin avantaj byk snm kabiliyeti ve yksek ekil verme kolayldr. Korozyona kar tercih edilen bir malzemedir. Kendi kendini tayan sistemlerde iskelet ve sa aksam iin hafif metaller kullanldnda tat arlklar nemli miktarda dmektedir. Korozyona kar dayankl olmalar nedeni ile de baz yerlerde Al - Mg - Si alam hafif metaller kullanlmaktadr.


asi Malzemeleri Karoseri Malzemeleri

Kaynak: Mohammed A. Omar; THE AUTOMOTIVE BODY MANUFACTURING SYSTEMS AND PROCESSES - 2011 John Wiley & Sons Ltd. ISBN: 978-0-470-97633-3

Figure: Figure: The material usage trend in automobile bodies

Audi Q7 Servis Eitimi

2006 Model Passat

Kaynak: Mohammed A. Omar; THE AUTOMOTIVE BODY MANUFACTURING SYSTEMS AND PROCESSES - 2011 John Wiley & Sons Ltd. ISBN: 978-0-470-97633-3

A typical automobile is composed of variety of materials to constitute its structure, aid its mobility function, e.g. tires and fluids, and provide comfort to its occupants, e.g. glass and refrigerants.

Figure: The materials in a typical sedan

Reading text - Body materials

Sheet steel Sheet steel of various grades (see Vehicle-body sheet metal is customarily used for the vehicle body structure. Sheet thicknesses range from 0.6 ... 3,0 mm, with most pieces being between 0.75 and 1.0 mm thick. Due to the mechanical properties of steel with regard to stiffness, strength, economy and ductility, alternative materials for the vehicle body structure are not yet available. High Strength low-alloy (HSLA) sheet steel is used for highly-stressed structural components. The resulting high strength of these components allows their thickness to be reduced. Ref: Automotive Handbook - Bosch


Aluminum In order to reduce weight, aluminum can be used for separate body components such as the hood, luggage-compartment lid, etc. Since 1994, an aluminum body has been in use for one of the German luxury-class cars. The vehicle's frame is constructed from aluminum extruded sections, and the sheet components are self-supporting in integrated form (ASF Audi Space Frame). The realization of this principle necessitated the employment of suitable aluminum alloys, as well as new production processes and special repair facilities. According to the manufacturers, the rigidity and deformation characteristics are identical to those of steel or are even superior. Ref: Automotive Handbook - Bosch

An Increasing Trend

http://www2.prnewswire.com/mnr/duckerworldwide/37515/

1 pound = 453,59237 gram

Automotive Handbook - Bosch

Table: Examples of alternative materials

Plastics: Plastics as materials for separate body components are used in a limited number of cases in place of steel.


asi ve Gvde Arzalar

GVDEDE OLUAN ARIZALAR Anma: Gvdedeki balant yerlerinin gevemesi ve geveyen yerlerin harekete gemesi anmaya neden olur. Bu yzden zaman zaman yaplan kontrollerde geveyen yerler tekrar sabitlenmelidir. Bu ilem ara gvdesinin mrn uzatr. atlama ve Krlmalar: Bu olay gvdenin zayf noktalarnda meydana gelebilir. Anormal sr yntemleri, zorlamalar ve imalat hatalar atlamalara/kopmalara sebep olabilir. Ani yol darbelerinden korunmak iin aracn iyi bir sspansiyon sistemi olmaldr. arplma, Eilme ve Burulmalar: Genellikle kaza sonras meydana gelen bu arzalar tekrar dorultmay gerektirir. arpklklar her zaman gzle grlmeyebilir, ancak iyi bir lme ile anlalabilir. Gvdede oluan arzalar tespit etmek amac ile lm yaplmaktadr. arpklklar direksiyon kontroln (ynlendirme stabilitesini) nemli derecede etkiler ve lastik anmalarna sebebiyet verir. Bu yzden arpklk nemli bir konudur.


AS ARIZALARI Korozyon: Tuz ve bazlarda bulunan hidroklorik asidin sebep olduu kimyasal ve fiziksel anma Oksitlenme: D ortamda buluna oksijenin (havann) sebep olduu kimyasal ve fiziksel anma Eilme, Geveme, atlama ve Krlma: Ar ykleme ve kt yol koullarnda arac uygun hzla srmemekten meydana gelirler. st yap reticilerinin yanl delik amalar da

atlamalara neden olur. Onarm yaplmazsa atlak yerler krlr.

Viraj ilerindeki ar hzlar burulmalara neden olurlar.

asideki eilme ve burulmalar gelimi asi dzeltme cihazlarnda standart llere uygun olarak yaplmaldr.

EKLER - 1

Today, most smaller vehicles such as small SUVs and sedans use a unibody (or monocoque) construction.

Heavy-duty vehicles like trucks and busses still use the idea of body-on-frame.

Regardless of the construction technique, steel is still the predominant material used in automotive frames.

Brian Goff, Mario Grasso, Oscar Briceno, Automobile Materials, SRJC - ENGR 45 Semester Project (Fall 09)

Monocoques Typical Ladder Frame

Brian Goff, Mario Grasso, Oscar Briceno, Automobile Materials, SRJC - ENGR 45 Semester Project (Fall 09)

Toyota

i35

n cam Arka spoyler Motor alt koruma Lastik deflektrleri (4 adet)

Ara karoseri

i35

Ara karoseri Aero dynamics: 1. Windshield glass is aerodynamically designed with a pin that prevents the wiper

from lifting, thus minimizing wind noise during high speed driving. 2. Rear spoiler: Continues roof line and reduces wind noise 3. Engine undercover: Smooth surface increases the aerodynamics on the underside of

the vehicle and contributes to a reduced fuel consumption. Further it offers protection when driving off-road.

4. Wheel deflectors: Deflect wind around the wheel openings for better aerodynamics.

The application of high density hood insulation and sound deadening foam a the pillars further contributes to a low noise in the passenger compartment. All directional safety design: Hollow side members gradually increased in diameter from front to back for

improved impact absorption. Rear frame member reinforced. Fuel filler neck base moved forward Side members are designed straight for better impact absorption High tensile steel is utilized for greater safety from impact and weight reduction. Center B pillar is designed as one piece internal roll bar. Hyundai provides a 12 year anti perforation warranty for the vehicle body.

sasi-ve-karoseri.pdf

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asi ve karoseri

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