Lecture 17 - Mechanical elements: space frames. The following will be discussed in this chapter: Facts about car structure, frames, trusses, planar truss, space truss, 2D truss, how to calculate truss? method of joints,. | Design web Design web ME 1110 – Engineering Practice 1 Introduction Engineering Drawing and Design - Lecture 17 Mechanical engineering deals mostly with machines and mechanisms. Civil engineering deals with structures. Some structures are very interesting for mechanical engineers: Mechanical Elements Space frames » Airplane fuselage » Machine frames » Car chassis Prof Ahmed Kovacevic School of Engineering and Mathematical Sciences Room CG25, Phone: 8780, E-Mail: 1 Ahmed Kovacevic, City University London Formula student project - design of a racing car 2 Ahmed Kovacevic, City University London Design web Design web Facts about car structure Facts about car structure - 2 Chassis Space frame » The most common type of structure used on the early cars 1900’s » Still used on trucks & lorries, Black-Cab taxis » It provides structural platform onto which is mounted a body. Example: in the UK the Land Rover ‘Defender’ and ‘Discovery’ Monocoque » It is currently the standard structure for most cars made around the world in high volume production (100,000+per annum). First introduced by Budd in 1930’s. » Constructed from pressed sheet steel, it combines the function of both chassis and body in a three dimensional structure. » In its purest sense, the term monocoque is applied to a structure which relies entirely on its outer skin for strength. » Most cars (except Jaguar E type) have additional stiffening elements – ‘Semi-monocoque’ » Lighter then chassis and easier to manufacture 3 Ahmed Kovacevic, City University London » Originally developed for performance cars such as Maserati in the early 1950’s. as ‘cage’ of welded tubes onto which a non-structural body shell is attached. » The spaceframe, unlike the monocoque, relies on an internal tubular cage or frame to provide all the load bearing qualities of the vehicle. » Spaceframes are more labour intensive than the welded steel monocoque due a
