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As passenger vehicle design evolves and accelerates, the use of multi-body dynamics solvers has proven to be invaluable in the engineering workflow. MBD solvers allow engineers to build virtual vehicle models that can accurately simulate vehicle responses and calculate internal forces, which previously could only be assessed using physical prototype builds with hundreds of measurement transducers. Evaluation and selection of solvers within an engineering environment is inherently a multi-dimensional activity that can include ease of use, retention of previously developed expertise, accuracy, speed, and integration with existing analysis processes. We discuss here some of the challenges present in developing capability and accumulating data to support each of these criteria. Developing a pilot model that is capable of being applied to a comprehensive set of use cases, and then verifying those use cases, required significant project management activity.

This study aims to develop a virtual structural durability procedure for the formula SAE chassis and apply it on 2015 Maua Racing vehicle in order to identify potential durability concern areas and mass reduction areas. Quasi-static load cases were developed, based upon acceleration experimental data and analytical load transfer function, to represent the vehicle dynamic behavior at several work conditions. Virtual simulations (multibody and finite elements) indicate that 2015 chassis meets the targeted durability criteria for both peak loading and fatigue damage. Borderline regions were verified considering peak loading target and a special attention should be paid to them during reduction mass studies avoiding the target violation. Other regions present structural stress considerably lower than material capability, what indicates significant mass reduction potential.

This study presents the comparison of vehicle handling performance results obtained using physical test tire data and a tire model developed by means of Finite Element Method. Real tires have been measured in laboratory to obtain the tire force and moment curves in terms of lateral force and align torque as function of tire slip angle and vertical force. The same tire construction has been modeled with Finite Element Method and explicit formulation to generate the force and moment response curves. Pacejka Magic Formula tire response models were then created to represent these curves from both physical and virtual tires. In the sequence, these tire response models were integrated into a virtual multibody vehicle model developed to assess handling maneuvers.

This paper presents the results of a study about the influence of the suspension manufacturing and assembly induced dimensional variation on the vehicle dynamic behavior for a compound crank rear suspension. A selection of representative vehicle dynamics metrics has been considered for this assessment and each individual dimensional variation has been categorized with respect to its overall effects on the selected metrics. By doing this, it is possible to identify the critical points where the dynamic behavior of the vehicle is more sensitive to the resulting dimensional variation, therefore creating a new criteria to define the appropriate tolerance control for the manufacturing and assembly of the related parts.

The Brazilian automotive market presents special characteristics: at the same time that it demands similar technologies applied in developed markets like USA and Europe for luxury cars, in the sub-compact entry-level segments (a segment where the profit margin is very tight) there are unique characteristics that justify the development of different cars. Taking into consideration the mini cars segment, there is no car developed specifically for the Brazilian market. While the mini cars development for the entry level segment is still rare, every new auto show presents new proposals and some of them are on the streets, but most are mainly focused in the luxury segment. These vehicles currently in the market are in a price range where it is not economically feasible for them to be acquired by someone who is coming from a motorcycle-based usage.

The Formula SAE competition has the purpose to stimulate the engineering students to work in teams to develop a concept, design and build small racing vehicles. In this competition, students are motivated to build a high performance car, reliable and with low development cost. The success of the team in the competition is determined with a detailed analysis of all aspects involved. Considering the frame development, some key points must be considered for the structural performance: stiffness, durability, modal and safety response. This papers focus on the stiffness analysis to verify if the frame torsional stiffness is compatible with the respective suspension for the level of performance required. The study was performed using the frame of 2012 Formula SAE from Instituto Mauá de Tecnologia using beam elements to model the frame structure in a FEA (Finite Elements Model) software to simulate the system stiffness.

Analytical models are very useful to the vehicle dynamics project engineer in order to provide simple solutions that bring at the same time a deep understanding of the physical phenomena being studied. Due to their structure, the input of analytical models are only the variables of interest affecting the concerned handling metrics - this fact reduce the parameters quantity to build the same model, making them proper choices for advanced studies. Additionally, analytical models are more efficient in computational terms, aspect convenient for studies that involve large amounts of calculation iterations like numerical optimization processes. This paper presents analytical model results for the roll gradient, understeer gradient and steering sensitivity metrics and proposes enhancements in order to obtain results with accuracy compatible to the experimental measured variables.

The required hand wheel effort the driver inputs into the steering wheel during parking maneuvers is an important design factor for a vehicle, that has a strong influence on the customer's overall perception of steering performance. During the development of a new vehicle, the designer is faced by the challenge of achieving the desired level of steering effort without jeopardizing other handling characteristics, like steering sensitivity and on-center performance. The suspension and steering tuning to achieve the adequate trade-off between these different metrics is especially critical for manual steering systems, which is a very common configuration for emerging market vehicles. In addition, due to communization of architectures, it is common that a vehicle with a manual steering system must share common suspension components and geometric parameters with configurations that have power steering assistance, making this trade-off even more difficult.

The sheet metal joining through spot welding is the most widely used process for automotive body building, where an average vehicle has around 5,000 spot welding points in its structure. In this sense, the spot welding project is critical to the final product performance and it must be done in a way that can assure both quality and durability of the vehicle, already taking into consideration the fact that the spot weld mechanical properties related to fatigue and rupture resistance are much lower when compared to other available welding techniques like MIG welding for example. These properties have a direct impact in the fatigue durability and crashworthiness properties of the vehicle, as a significant part of the structural resistance goes through these spot welds. With this scenario, the correct application of FEA techniques is very important to assure that the projected joints and spot weld disposition meet the product targets in terms of safety and durability.

Traditional suspension tuning for ride comfort takes use of a series of physical prototype evaluations by skilled drivers, who analyze the vehicle performance in subjective terms. In this approach, the suspension components (springs, shock absorbers, bumpers, etc) are usually optimized one at a time, regardless of the consequences of the interactions among them in the global suspension behavior – this not uncommonly leads to sub optimized suspension configurations. Another problem with this approach is the fact that it is completely dependent upon physical component prototypes, whose costs and construction lead times can not be afforded in the current tight development cycles. This paper presents an objective approach that has been successfully applied at GMB, based on simulation tools, whose target is to define optimized components for the suspension without the need of physical prototypes.

This paper subject is to define the usage characterization, suspension system functions, influence parameters and the methodology applied to get a desirable ride and handling vehicle behavior. Using robust engineering concept as process guideline, Virtual Ride® software for math simulation and General Motors Cruz Alta Proving Ground tracks to subjective evaluations will result in a robust and appropriated suspension configuration considering a large range of system components specifications achieving the desired vehicle personality.

This work has the proposal of showing the correlation between simulation and field tests’ results for handling maneuvers for Astra and Corsa vehicle platforms. Adams was the main tool used during the modeling development and the correlation was performed for steady state maneuvers (constant radius cornering) and transient maneuvers (series of lane changes at high speed and elk test).

The vehicle design environment from a crashworthiness and safety perspective has become increasingly complex in recent years. New legal requirements imposed by the European Union (EU) and the United States National Highway Traffic Safety Administration (NHTSA) have created a design space of great complexity with many parameters that must be balanced to arrive at an overall design that performs adequately in all of these situations. The customer introduces further complexity through the addition of Consumer requirements in many markets that will influence a purchasing decision. In order to design to all of these conditions, an approach of using physical testing solely has problems associated with it. Due to the prohibitive nature of vehicle prototypes and limited availability during Engineering Development, other tools such a Computer Aided Engineering (CAE) have become popular.