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In the UK it is a requirement for all newly registered coaches to be Type Approved for rollover crashworthiness in accordance with ECE Regulation 66 (R66). This regulation ensures the stability of the coach structure during rollover accidents in order to maintain a passenger survival space. This paper details the approval of a new coach that used two composite rollbars (front and rear) to absorb the majority of the energy during rollover. The coach was subjected to a full-scale rollover test in order to gain the necessary approval. Additionally to the Type Approval, a computer model was developed to help predict the full-scale rollover test. The model consisted of a detailed finite element mesh and was analysed dynamically using the LS-Dyna3D software. The computer model was calibrated using the full-scale test data so that it could be used to gain future Type Approvals for modifications to the coach structure.

This paper describes additional and more recent results from the DaimlerChrysler study of HANS that includes a sensitivity analysis of HANS performance to variations in crash dummy neck length and other impact test conditions. The objective of the tests was to determine the robustness of the HANS concept in a variety of conditions that might occur in actual use. The results show that the variations in test parameters do effect injury measures from the crash dummy, but HANS provides substantial reductions in injury potential in all cases compared to not using HANS. Also, no injuries were indicated with HANS.

A comparative investigation of airbag and HANS driver safety systems was carried out (HANS, is a Registered Trademark in the U.S.A.). With both systems, head and neck loads were reduced from potentially fatal values to values well below the injury threshold. Both systems performed similarly in reducing the potential for driver injury. For this reason and given the high costs of development and testing, there is no justification for further development of airbags for racing.

This paper presents the design detail of the Lear Extractable Safety Seat, which has been developed in conjunction with the FIA and Stewart Grand Prix for use in the Formula One race car cockpit. The seat is designed for use in the event of an accident that renders the driver incapacitated. The Extractable Seat allows the driver to be fully immobilized for extrication without the need for torso manipulation. This minimizes the risk of exacerbating any potential spinal injuries, while allowing for efficient removal of the driver from the cockpit. The seat was introduced at the 1998 Japanese Grand Prix, and the design has now been specified by the FIA as mandatory for all formula one cars from the 1999 season and beyond. Continued developments are currently underway for the next generation seat in order to improve efficiency of the system and address issues from its first season of implementation. The status of these developments is also presented in this paper.

The Formula SAE and Formula Student competitions, held every year in the USA and UK, challenge teams of engineering students to design and build a small single-seater racing car. The University of Leeds has entered teams into these competitions for the past four years and has developed an award winning hybrid monocoque chassis design. The design enables a light, stiff and extremely safe chassis to be produced at a reasonable manufacturing cost. A chassis which is torsionally stiff enables a desirable roll moment distribution to be achieved for good handling balance. A chassis which can absorb high energy impacts whilst controlling the rate of deceleration will increase the likelihood of drivers surviving a crash without injury. This paper describes how Finite Element Analysis (FEA) techniques have been used to investigate both the torsional stiffness and crashworthiness of the chassis and how physical materials testing has been used to ensure the results are accurate.

Since 1995, Queen's University has been competing in the annual Formula SAE® competition. The first three formula cars were of conventional construction consisting of a tubular welded steel frame and welded steel suspension components. In the summer of 1997 the team began design and construction of their first monocoque chassis. A technique referred to as cut and fold was to be used for the construction. The material selected for the monocoque was a balsa-wood core with aluminum skins, commonly used in the aircraft industry. An innovative method to produce suspension arms with the use of an adhesive was also developed. The main objective in the design of the aluminum composite monocoque was to reduce the weight, increase stiffness, and simplify the design of the racecar. During the initial design stages it became evident that the composite monocoque would have many advantages over the steel frame, such as fewer components and the absence of welding.

There are several fundamental design parameters that determine a race car's performance including mass, centre of gravity height, static load distribution, engine power and aerodynamic forces. A sensitivity analysis is performed on these and other parameters to determine their effect on vehicle performance. This is achieved by looking at specific manoeuvres such as straight line acceleration, braking and steady state cornering to determine the relative effect of the respective parameters. The results presented are determined for both the Leeds University Formula SAE car, figure 1, and a typical mid - late 1990's Formula One car. The results further provide an insight into the differences between high speed cars effected by aerodynamics and low speed cars where aerodynamics makes little or no difference to performance. Combining the performance for a set of manoeuvres provides an insight as to how to improve the overall vehicle lap time.

In this paper, the impact energy absorption behavior of carbon and glass fiber composite materials will be discussed. In particular, the crush behavior of cylindrical and conical structures will be evaluated based on micromechanical failure modes. Studies show that stiffness and strength of the constituent materials alone cannot be used to design impact structures. Experimental results also show that by controlling the mode of micromechanical damage, crush efficiency can be maximized. Moreover, crushed structures which form many microcracks in the fiber and resin have increased energy absorption. Based on these results, some generic design guidelines for improving the energy absorption capacity of composite structures will be shown.

This paper considers the way in which engineering knowledge develops through a process of codification that facilitates innovation and imitation by competing firms. In a chronological case study of the development of ground-effect aerodynamics in Formula One racing, this paper reviews the way constructors, such as Lotus, Williams, Brabham and Ferrari, develop and respond to the innovation of ground-effect aerodynamics. We use the case study to generate a series of implications for the way in which firms manage and influence leading edge engineering knowledge.

A road simulation system has been developed at the Langley Full-Scale Tunnel (LFST) to support the aerodynamic testing of NASCAR-class race cars. The leading edge of the existing ground board was recontoured to alleviate a separation bubble and an active suction boundary layer control system, incorporating a bleed slot and axial flow blower, has been implemented. Performance evaluations include boundary layer surveys at various locations in the vicinity of the car balance with the empty tunnel as well as force measurements with a representative vehicle both with and without the boundary layer control system operating.

As the popularity of motorsport continues to surge throughout the world, so to does the level of competition in the motorsport community. Participants work to achieve a performance edge through superior engineering. As an enabling tool, the wind tunnel has become a focus for enhancing performance. This is evidenced by the increasing interest among motorsport teams in dedicated wind tunnel facilities, as best exemplified by the Formula One community. Part of the reason for this increasing focus on wind tunnels is the availability of breakthrough technologies that better simulate on-track conditions, providing new opportunities to enhance performance.

A full-scale investigative wind tunnel test was performed on a dirt track race car in the Langley Full Scale Tunnel (LFST). Lift and drag forces were measured and flow visualization studies performed for the purpose of quantifying the aerodynamic characteristics in order to assist designers and drivers of this class of vehicle. Results from the downforce measurements showed a rear axle biased aerodynamic balance. Flow visualization studies revealed large areas of separated flow on the forward portion of the side pods as well as over a large portion of the rear deck and spoiler behind the driver.

A description of the new Lola Cars International 50% Scale Aerodynamic Wind Tunnel is presented in the following paper, including results of the recently completed commissioning programme. The wind tunnel is a hybrid of old and new; a large part of the shell is from a retired British Aerospace wind tunnel and includes a new test leg incorporating a rolling road and high-precision overhead balance. The new wind tunnel exhibits flow quality that is better than the former British Aerospace wind tunnel.

This article describes both a computer-aided engineering tool - a computer model - utilized in accelerating design tasks and also the process of building a powertrain design knowledge. The computer model, which integrates engineering and analysis phases into the design process, has been developed to enable rapid evaluation of new powertrain concepts. The model determines the basic geometry of engine and transmission subsystems and components, and allows automation of the engineering and analysis processes. Examples of application of the tool in evaluation of powertrain concepts and the design of components and subsystems are also given.

The paper discusses the design of a racing motorcycle engine to compete in World Superbike racing. This class of motorcycle racing is based on production machines with four-stroke engines only. The rules allow three engine variants to be used, a 750 cm3 four-cylinder engine, a 1000 cm3 twin-cylinder engine, and a 900 cm3 three-cylinder engine. To date only the first two variations have been employed but this paper shows that the 900 cm3 engine has the highest potential power output of the set. This is demonstrated using engine simulation software and the finest detail of the design of the engine and its ducting are supplied within the discussion. The input data for the engine simulation is provided by empiricism so that the design is initially well-matched from the intake bellmouth to the end of the exhaust system. The outcome of this empirical process is confirmed by the engine simulation to be a relevant initial design procedure.

Enthusiasts, accident reconstructionists and racing personnel have always been interested in wheel torque and HP values for vehicles. Modifications to the engine and/or driveline cause factory data to be in error, and special racing engines have no such data available in any case. Engine dynamometers provide useful information, but require the engine to be removed from the car before any testing can occur. Of more interest, particularly in competition situations, is the effect of changes at the driving wheels. We focus here on a simple method of deriving rim torque and HP values from accelerometer data. The data can be acquired using nearly any sufficiently accurate accelerometer package, and the calculations involved can be done by hand or with a spreadsheet program. Unknown vehicle characteristics can be extracted from coastdown tests. Use of a chassis dynamometer is not required.

Air Force (AF) pilots experience forces during emergency escape and/or crash with potential for head and neck injuries. These forces are increased by aerodynamic and inertial properties of current helmet-mounted systems used for flight display and targeting. The motorsports industry has documented many injury-causing crashes and has a higher incidence of mishaps. The Air Force Research Laboratory (AFRL) has entered into cooperative research with motorsports to establish a relationship between multi-axis impact acceleration and injury for improving pilot/driver protection concepts. This paper reports the development and preliminary results of using an instrumented race helmet to obtain head accelerations during racing mishaps. These data may be used to calculate neck loads for correlation to injury, and to revise impact tolerance criteria pertinent to military and commercial crash protection.

This paper presents the results of an extensive test program conducted on behalf of Stewart Grand Prix at Lear Corporation's Technology Division in Southfield, Michigan. This project was conducted in conjunction with Bell Sports, Impact Medical Technologies, and Kistler Instrumentation. The scope of this project was two-fold. The 1st goal was to evaluate alternative materials for the current head surround to improve head impact protection in the F1 cockpit. This involved 2 phases of testing. First was a series of headform drop tests to characterize material performance. A hyge sled test program was then conducted to evaluate the effects of the head surround on occupant head and neck loads during crash simulation. A correlation between these two types of tests is investigated in order to define criteria for future development. The 2nd part of this project involved the evaluation of head acceleration response during the hyge sled tests.

The paper aims at introducing the developments of a performance simulation method for predicting the potential lap time of a given racing car on a given circuit. It is based on a previous work published in [1]. This first attempt produced fairly reliable results but it was not totally satisfactory since computation was very slow. It was then decided to restart from scratch with the following approach. Reference is made to the renowned «Milliken» [2]. The vehicle maximum G-G envelope is estimated. Then the model follows the «real» raceline -acquired with on-board instrumentation- performing within the G-G envelope. Accurate comparison with real-world data is used to identify and calibrate some of the model parameters. After calibration the model can be used to study the effect of different set-ups, aerodynamic balance, gear ratios etc. Where the circuit is new to the team a trajectory can be designed on a circuit map by using a built-in, parametric CAD-like interface.

Considerable effort has gone into modelling the performance of the racing car by engineers in professional motorsport teams. The teams are using progressively more sophisticated quasi-static simulations to model vehicle performance. This allows optimisation of vehicle performance to be achieved in a more cost and time effective manner with a more efficient use of physical testing. Racing cars are driven at the limit of adhesion in the non-linear area of the vehicle's handling performance. Previous simulations have modelled the transient behaviour by approximating it with a quasi-static model which ignores dynamic effects, for example yaw damping. This paper describes a comparison between different cornering modelling strategies, including steady state, quasi-static and transient. The simulation results from the three strategies are compared and evaluated for their ability to model actual racing car behaviour.