G. Savage/ Engineering Failure Analysis 17 (2010)92-115 data concerning their performance. It is most likely however that the use of wood as a chassis material was due in the main to cheapness and convenience rather than to enhance performance. Up until the early 1950s the predominant method of Formula 1 chassis construction consisted of a tubular aluminium space frame surrounded by hand worked aluminium body panels. At that time random orientation glass mat and polyester resins(Glass Reinforced Plastic)developed in wartime re- search became widely available. This material allowed the relatively cheap production of complex compound curvature bodywork which replaced aluminium. The use of grP panelling continued right through to the late 1980s. The first truly composite chassis was built in the early 1960s by Cooper cars. The structure consisted of a hand worked aluminium outer skin, an aluminium honeycomb core and a GRP inner skin. a single piece outer skin was produced from a number of panels to form the final aerodynamic surface of the car. The aluminium honeycomb core was then bonded to the inside of the outer skin using a phenolic resin film adhesive. The inner skin of grP was similarly bonded to the structure in a eparate operation. although the car never actually reached the track, it was to become the basis of Formula 1 chassis design for the next two decades. In the mid-to-late 1970s the preferred method of composite chassis construction used aluminium kinned, aluminium honeycomb material fabricated using the cut and fold"method. The tubs were formed from pre- bonded sheeting which was routed, folded and riveted into the appropriate shape( Fig. 14). The various teams involved later e-formed the skins prior to bonding to the core using an epoxy film adhesive. Carbon fibre composite chassis were first introduced by the Mclaren team in 1980 3. They consisted of pseud lithic arrangement laid up over a"male"mould or mandrel using unidirectional(UD)carbon fibre prepreg tape ( Fig. 15). The mandrel, made of cast and machined aluminium alloy was dismantled for removal through the cockpit opening following an autoclave cure of the composite. a three stage cure was required: one for the inner composite skin, a second to cure the epoxy film adhesive which attached the honeycomb core and a third for a further adhesive layer and the structure 's outer skin. The basic design and manufacturing process remained essentially unchanged for a number of years and was still the basis of chassis construction at McLaren up until the 1992 season. There is some debate as to which team was the first to produce a fibre reinforced composite chassis since the Lotus team were carrying out similar research in parallel with McLa- Fig. 14."Cut and fold"aluminium honeycomb chassis (late 1970s). Fig. 15."Male moulded"chassis manufacturdata concerning their performance. It is most likely however that the use of wood as a chassis material was due in the main to cheapness and convenience rather than to enhance performance. Up until the early 1950s the predominant method of Formula 1 chassis construction consisted of a tubular aluminium space frame surrounded by hand worked aluminium body panels. At that time random orientation glass mat and polyester resins (Glass Reinforced Plastic) developed in wartime re￾search became widely available. This material allowed the relatively cheap production of complex compound curvature bodywork which replaced aluminium. The use of GRP panelling continued right through to the late 1980s. The first truly composite chassis was built in the early 1960s by Cooper cars. The structure consisted of a hand worked aluminium outer skin, an aluminium honeycomb core and a GRP inner skin. A single piece outer skin was produced from a number of panels to form the final aerodynamic surface of the car. The aluminium honeycomb core was then bonded to the inside of the outer skin using a phenolic resin film adhesive. The inner skin of GRP was similarly bonded to the structure in a separate operation. Although the car never actually reached the track, it was to become the basis of Formula 1 chassis design for the next two decades. In the mid-to-late 1970s the preferred method of composite chassis construction used aluminium skinned, aluminium honeycomb material fabricated using the ‘‘cut and fold” method. The tubs were formed from pre￾bonded sheeting which was routed, folded and riveted into the appropriate shape (Fig. 14). The various teams involved later pre-formed the skins prior to bonding to the core using an epoxy film adhesive. Carbon fibre composite chassis were first introduced by the McLaren team in 1980 [3]. They consisted of pseudo-mono￾lithic arrangement laid up over a ‘‘male” mould or mandrel using unidirectional (UD) carbon fibre prepreg tape (Fig. 15). The mandrel, made of cast and machined aluminium alloy, was dismantled for removal through the cockpit opening following an autoclave cure of the composite. A three stage cure was required: one for the inner composite skin, a second to cure the epoxy film adhesive which attached the honeycomb core and a third for a further adhesive layer and the structure’s outer skin. The basic design and manufacturing process remained essentially unchanged for a number of years and was still the basis of chassis construction at McLaren up until the 1992 season. There is some debate as to which team was the first to produce a fibre reinforced composite chassis since the Lotus team were carrying out similar research in parallel with McLa￾Fig. 14. ‘‘Cut and fold” aluminium honeycomb chassis (late 1970s). Fig. 15. ‘‘Male moulded” chassis manufacture. G. Savage / Engineering Failure Analysis 17 (2010) 92–115 99