Integrated development of CFRP structures for a topless high ...

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Integrated development of CFRP structures for a topless high performance vehicle










Integrated development of CFRP structures for a topless
high performance vehicle
Paolo Feraboli
a,*
, Attilio Masini
b
, Luigi Taraborrelli
c
, Andrea Pivetti
c
a
Department of Aeronautics and Astronautics, University of Washington, Box 352400, Seattle, WA 98195-2400, USA
b
Advanced Composites R&D Division, Automobili Lamborghini S.p.A, Sant Agata Bolognese, Italy
c
Analysis Department R&D Division, Automobili Lamborghini S.p.A, Sant Agata Bolognese, Italy
Abstract
When modern saloon cars are re-engineered as convertibles (or roadsters) it is typical for them to lose 50% or more of the bodys
torsional rigidity. Consequently the vehicles rarely handle quite as crisply, nor do they ride as well as the coupes from which they derived.This paper highlights the fundamental contributions of advanced composites in achieving the desired value of handling of the Murcie`lagoRoadster without penalizing the overall weight of the vehicle. To compensate for the absence of the roof structure, the vehicle wasstrongly redesigned by introducing new structural members and reinforcing existing critical components. A new all-carbon/epoxy com-posite sub-frame, which spans the entire engine bay, is comprised of elliptical tubular members, and it is the rst of its kind in a pro-duction vehicle. Engineering of the sub-frame, from preliminary design to manufacturing decisions, is the focus of this paper, and isachieved through a Building Block approach that sets the program within the Integrated Product Development (IPD) strategy thatthe Advanced Composites Division of Automobili Lamborghini S.p.A. employs for its technology demonstrators. The strategy consistsin a concurrent analytical and experimental development of the product, from the initial conceptual design and coupon testing, throughthe stages of element and subcomponent engineering, to nal component manufacturing.
2005 Elsevier Ltd. All rights reserved.
Keywords: Polymer matrix composites; Selection of material processes; Destructive testing
1. Introduction
1.1. Background
The chassis of a car is the framework that provides the
mounting points for the suspensions, as well as the supportfor the steering mechanism, the power train, the fuel tankand the seats for the occupants, and every additional elec-trical cable and uid line fundamental for the operation ofthe vehicle. While fullling these functions, it has to pro-vide sucient rigidity for accurate handling, absorb crashenergy for the safety of the occupants, and resist opera-tional static and cyclic loads due to the interaction with
the road. Lastly, it needs to be light enough to increase fueleconomy and speed, and to reduce inertia, thereby increas-ing performance
[1]
.
A chassis is typically designed for stiness rather than
strength. It has to be sti enough not to inuence thedynamical behavior of the vehicle, and to resist large defor-mations, which can deter