Auto Integral (mono or unity) construction

Auto Integral (mono or unity) construction 

 Integral body construction employs the same principles of design that have been used for yearsin the aircraft industry. The main aim is tostrengthen without unnecessary weight, and theconstruction does not employ a conventional sepa-rate chassis frame for attachment of suspension,engine and other chassis and transmission compo-nents . The major difference betweencomposite and integral construction is hence thedesign and construction of the floor .In integral bodies the floor pan area is generallycalled the underbody. The underbody is made up offormed floor sections, channels, boxed sections,formed rails and numerous reinforcements. In mostintegral underbodies a suspension member isincorporated in both the front and rear of the body.The suspension members have very much the sameappearance as the conventional chassis frame fromthe underside, but the front suspension membersend at the cowl or bulkhead and the rear suspen-sion members end just forward of the rear bootfloor. With the floor pan, side rails and reinforce-ments welded to them, the suspension membersbecome an integral part of the underbody, andthey form the supports for engine, front and rearsuspension units and other chassis components. Inthe integral body the floor pan area is usually ofheavier gauge metal than in the composite body,and has one or more box sections and several chan-nel sections which may run across the floor eitherfrom side to side or from front to rear; this varietyof underbody construction is due largely to thedifference in wheelbase, length and weight of thecar involved. A typical upper body for an integralconstructed car is very much the same as theconventional composite body shell; the majordifferences lie in the rear seat area and the con-struction which joins the front wings to the frontbulkhead or cowl assembly. The construction in thearea to the rear of the back seat is much heavier inan integral body than in a composite body. Thesame is true of the attaching members for the frontwings, front bulkhead and floor assembly, as theseconstructions give great strength and stability tothe overall body structure.