Background reading/research

Early Chassis Design & Ladder Frame Chassis

"Two long rails running the length of the vehicle, with the engine mounted between hem and the axles suspended underneath. The body would then be mounted on top of the chassis. This kind of chassis is generally known as a ladder-frame design .. . "

"It takes time to make all the joints, and the resulting structure suffers from a lack of diagonal bracing- it can be easily twisted along its length."

"... stronger more rigid chassis involved adding extra members and using thicker material, which adds in weight."

"Ultimate load capacity ... load-carrying capacity that results in the ladder frame chassis still being used for the majority of trucks and commercial vehicles."

"Its adaptability ... shortened, lengthened, widen, or narrowed quite easily."

Space-Frame Chassis

"The suspension and steering systems on cars are designed on the basis that the are mounted to a solid object."

"A ladder frame chassis is stiffer...  add bracing to prevent twist."

"No twisting forces acting on it just compression and tension. space frames removing bending forces acting on a chassis members allow it to be made smaller, thinner and lighter... stiffer overall."

"...each member is only loaded in the direction which it is strongest."

"This structure is much stiffer than a ladder-frame chassis at a far lower weight."

"without much space"

"...even distribution of loading so isn't suited to carrying a couple of tons..."

"...all sections actually have to be welded together accurately."

"hugely labour-intensive exercise"

"space-frame chassis remains a very popular way of building high-performance vehicles where speed of production, interior space, and ultimate stiffness & weight-reduction can be sacrificed in exchanged for being able o use relatively basic materials and techniques."

A space-frame chassis distributes loads across the whole structure.

Backbone Chassis

"If the passenger area is hung on the outside of the chassis, there will be no issue to fit the bracing in place. ... moving the chassis rails closer together to fit between the seats, the loss of stiffness this would cause can be compensated for by the fact that one can now add almost unlimited bracing to this central area. "

"... slightly stiffer than a space frame of the same weight."

"... lend itself better to small or medium sized vehicles."

Floorplans & Tubs

"chassis is purely from sheet metal"

"... take lots of individual pieces of metal, fold them into tubes and weld them together .... press two large sheets of metal with lots of ribs ... sandwich them together ... ribs form tubes between the two sheets . "

"An improvement on the floor plan idea is to build a tub out of sheet metal or composites ... the tub help add stiffness."

Monocoque (single shell) Chassis

"... no matter how light the chassis is made, weight is going to be added when the body panels is placed."

"... the body panel could be used themselves as chassis members, and eliminate weight."

"instead of only making sandwich tubes for the floor, the same can be done for the side panels as well. If a floorpan is like ladder-frame made from pressed sheet, then a monocoque is like a similarly constructed space-frame."

"... monocoque construction is now the technique of choice for mass-production vehicles."

"the pressed-steel-panel monocoque is currently the best compromise available once if concerning about cost and production."

"... thinner material ... easier to buckle ... he safety enhancing crumple zones built into modern cars. the energy of a crash o be distributed around several panels, crumpling them in the process, the length of tie it takes the vehicle to come at a full stoop is extended ... reducing the accelerative forces on the occupants. "

Sub-Frames

"a sub frame design is used in conjunction with a monocoque design ... allows to assemble the components together before assembling the whole vehicle, and gives the adaptability benefits of a ladder-frame chassis."

"The chief advantage is that the chassis can have very tight, accurate tolerances on the sub assembly."