BY

KALYAN SRIKAR MAJETI

CONTENTS……

Chassis introduction

Types of chassis

Different types of latest structures

Various cars and their chassis

Introduction….

Chassis is the significant structure of an automobile

A skeletal frame with various mechanical parts like engine, tires, brakes, steering and axle assemblies

Usually made of a light metal or composite plastic which provides strength needed for supporting vehicle components and load on it

Types of chassis….

Ladder frame chassis Tubular space frame chassis Monocoque frame chassis Ulasab monocoque chassis Back bone frame chassis Alluminium space frame Carbon fibre monocoque

Ladder chassis

One of the oldest form of chassis that is still used by most of the SUVs till today

Resembles a shape of ladder which having two longitudinal rails interlinked by several lateral and cross braces

The lateral and cross members provides rigidity to the structure

it has no much advantage these days…. Easy and cheap for hand built

Since two dimensional structure…. Torsional rigidity is much lower than other chassis especially with vertical loads or bumps

Most SUVs , classic cars ,lincoln town car, ford crown victoria etc…..

Backbone chassis

Has a rectangular tube like a backbone and simple in structure

made of glass fibre is used for joining front and rear axle and responsible for the strength.

Space within structure used for positioning drive shaft in case of rear wheel drive.

Drive train, engine and suspensions are connected at the ends of the chassis

Strong enough for smaller sports cars and most space saving other than monocoque chassis

Does not provide protection against side impact or off-set crash and not strong for high speed cars

Lotus Esprit, Elan Mk2, TVR, Macros

Monocoque chassis

Most modern cars use this type A single piece of frame work that give shape

to the entire car and built by welding several pieces together

Demand for monocoque chassis is increased because it is suitable for robotized production

Inherently good crash protection and it is space efficient and cheap for mass production

Heavy , impossible for small volume production

Nearly all mass production cars, all current porche

Tubular space frame chassis

A 3-dimensional design employing number of circular and square section tubes

Tubes are positioned in different sections to provide mechanical strength against forces from anywhere

Tubes are welded together and form a complex structure

Very strong when compared with ladder and monococoque chassis of the same weight

Very strong in any direction

Very complex, time consuming to built and engages a lot of space , raise the door sill and results in difficult accessto the cabin

All ferrari before the 360m ,Lamborghini Diablo, Jaguar Xj220 ,caterham

Ulsab monocoque chassis

Traditional steel monocoque chassis becomes heavier than ever ,as a result car makers turned to replace steel with alluminium

More cars use alluminium in body panels American steel manufacturers hired Porsche

Engineering services to develop a new kind of steel monocoque technology calls Ultra Light Steel Auto Body (ULSAB)

Stronger and lighter than conventional monocoque without increasing production cost

Still not strong enough for best sports car

Opel Astra and BMW 3series

Carbon fibre monocoque chassis

Carbon fibre is the most sophisticated material using in aircrafts, spaceships and racing cars

Because of its superior rigidity to weight ratio Several carbon fibres used in motor industry

like Kelvar which has rigidity to weight ratio among them and can be found in body panels of many exiotic cars

Lightest and stiffest chassis

The most expensive

McLaren F1 ,Bugatti EB110SS, Ferrari F50

Aluminium space frame chassis ASF consists of extruded aluminium sections,

vacuum die cast components and aluminium sheets of different thickness

Highly stressed corners and joints and extruded sections are connected by complex aluminium die casting

40% lighter yet 40% stiffer than contemporary steel monocoque

Its quite complex

Lighter than steel monocoque and space effecient

Still expensive for mass production

Audi

One box design

Offers biggest interior space and can frees up the space by pushing windscreen forward

As the windscreen is pushed visibility is deteriorated

Cab forward design

Shortens the engine compartments ,move the windshield forward so that its base rests near the front wheels, this is the so called "Cab- forward" design. Chrysler tells us Cab forward design frees up the room for front passengers

Sandwich Structure –mercedes A class structure

This structure is called "Sandwich" because the horizontal-orientated engine is placed above the floor pan but under the cabin.

Because of the disappearance of the front enginecompartment, it made the car more compact than any other cars but simultaneously offers class-leading cabin space

It provides exceptional crash-protection and no additional crash structure is needed, thus a lot of weight is saved.