Automobili Lamborghini has been synonymous with cutting-edge innovation in the sports car world. Ahead of launching the first hybrid plug-in V12 high performance electrified vehicle, the company has unveiled a solution it says is unique in today’s automotive landscape.
Replacing the renowned sportscar brand’s mid-engine Aventador, Lamborghini’s new car, currently named the LB744, is based on an aerospace-inspired chassis, termed the ‘monofuselage’. As well as a monocoque made entirely of multi-technology carbon fibre, it features a front structure in Lamborghini’s Forged Composites; a special material made of short carbon fibres soaked in resin. This technology was patented and has been used by Lamborghini in its first structural applications as far back as 2008. In 2016 it won a JEC Composites Innovation Award for Automotive Interiors.
The monofuselage represents a significant step forward from the car maker’s previous Aventador model in terms of torsional stiffness, lightweight qualities and driving dynamics. What’s more, the LB744 is the first super sports car to be fitted with a 100% carbon fibre front structure. Carbon fibre is also used for the front cone structures to ensure a level of energy absorption that is significantly higher when compared to a traditional metal structure – double that of the Aventador’s aluminium front frame – combined with a substantial reduction in weight.
In fact, the LB744 monofuselage is 10% lighter than the old Aventador chassis, and the front frame is 20% lighter than its aluminium predecessor. The torsional stiffness has also been improved with a value of 40,000 Nm/°, up 25% compared to the Aventador and guaranteeing best-in-class dynamic capabilities.
The design concept underlying the development of the new monofuselage is based on the maximum integration between components. This is optimised thanks to the introduction of extensive Forged Composites technology, as well as the development of the monolithic rocker ring assembly. The LB744 single-element rocker ring-shaped component is made of CFRP and forms the supporting structure of the car. The rocker ring encloses and connects the Forged Composites elements, such as the tub, the front firewall and A pillar.
Forging ahead
Lamborghini’s Forged Composites is a type of carbon fibre sheet moulding compound material composed of small pieces of carbon fibre composite material that are pressed into shape as the resin sets. This contrasts to most carbon fibre composites, which are made of larger continuous layers that are laid up one at a time, often manually. The material and process allow for a higher range of shapes to be formed with precision, relative to traditional carbon fibre.
Forged Composites also contains higher fibre volume content, which combined with higher variation in strand orientation, increases the average strength and reduces variability over standard carbon fibre. The material is claimed to have one-third the density of titanium and equal or greater strength.
Approximately 500,000 intertwined fibres are used per square inch. The fibres contain intertwined and folded sheets of carbon atoms aligned with the length of the fibre, and the intertwining improves the fibre strength. The result is improved load carrying capacity as measured in bending per unit of mass.
Malleable moulding
Due to its chopped nature, Forged Composites can be moulded into much more complex geometries than traditional carbon fibre composites and is suitable to make 3D parts and parts which feature complex details, such as thickness transitions, holes, compound curvature. Lamborghini uses Forged Composite for structural components, and interior trim and seats of its cars.
The production of Forged Composites components also optimises efficiency and increases sustainability during the manufacturing process by reducing the energy consumption of cooling equipment and quantity of waste materials.
The more traditional, but no less efficient, technology of autoclave composite production with pre-impregnated material was retained for the roof construction. It is a manufacturing decision that also gives the customer maximum versatility in roof customisation.
Lamborghini says the LB744 represents a new ‘year zero’ in relation to the use of carbon fibre in car production, summed up in the acronym AIM (Automation, Integration, Modularity).
‘Automation’ refers to the introduction of automated and digitalised processes into material transformation, while preserving traditional Lamborghini manufacturing, such as in the discipline of composites. ‘Integration’ relates to the integration of several functions into a single component through the development of compression moulding. This process uses preheated polymers to enable the production of components with a wide range of lengths, thicknesses and complexity, ensuring optimum integration between components to guarantee high torsional stiffness. Finally, ‘Modularity’ refers to making the applied technologies modular and therefore more flexible and efficient to respond to all the product requirements and characteristics.
