Search Results

Nowadays, electromagnetic compatibility (EMC) has taken an important role in automotive development. This is because the effects that EMC can cause in a vehicle or on the environment. All systems contained in a vehicle emit EMC, and can be influenced by it also. During the vehicle design phase some variables have to be considered and improved to make the vehicle to be electromagnetic compatible. We can list the vehicle systems as electromagnetic generators or victims, as below: Generators: Ignition GPS transmission system Mobile phone transmission system Electrical motors Radars Power modules Victims: Sensors Cables Control modules (BCM, ECM, etc.) An example of a complete system subject to the EM effects is the X-by-wire (or drive-by-wire) system, where mechanical systems are substituted by modules, cables, sensors, actuators. This system has to be designed considering electromagnetic compatibility.

Among all types of vehicle crashes, rollover is the most complex and yet least understood. During the last decades, a constant increase in the studies involving rollover crashes and injuries associated with it can be observed. Although the rollover is not the most frequent type of accident, it is of the greatest significance with respect to injury and trauma caused to the vehicle occupants. The existing standards and procedures to test rollover crashworthiness are still not suitable to computer simulation because of the huge computational effort required, and the need of faithful/overly complex representation of the aspects involved in real crashes. The objective of the present work is the development of computational models particularly adapted to simulate different standards and procedures used to evaluate the vehicles' roof strength. The models are compared with other approaches, and their advantages/disadvantages are discussed.

Even though the rollover is not the most frequent type of accident, it is of the greatest significance with respect to injury and trauma caused to the vehicle occupants. The need to reduce death incidence and serious injuries has increased the importance of computational simulations and prototype testing. This study presents finite element model to simulate rollover events and to predict possible injuries caused in the head, neck, thorax and cervical spine. Numerical models of a sport utility vehicle (SUV) are simulated including anthropomorphic dummy to represent the driver. The injury risks and traumas are verified to the driver considering belted and unbelted dummies. The computational methodology developed proved to be efficient for the evaluation of the vehicle's roof structure in rollover events.

Test Protocols for pedestrian head protection in a car pedestrian accident have been discussed for several Technical Communities in order to identify ideal boundary test conditions to evaluate injury limits. With the purpose to harmonize with final Global Technical Regulation 9 for Pedestrian Protection published by ECE in January 2009, European New Car Assessment Program (ENCAP) has changed their Child and Adult headform weight and geometry boundary test conditions. However 5 Kph remains as difference between both protocols. This work presents a comparative head impact test analysis for both headform at ENCAP and GTR#9 boundary test conditions when performed at critical bonnet regions.

According to several customer perception survey, Squeak and Rattle (S&R) is among the top most annoying defects. Consequently, GMB engineering design, development and validation process must be continuously improved and consistently applied to all platforms to guarantee that all products are free from squeaks and rattles. This paper introduces those concepts and discusses some strategies to eliminate or minimize S&R. Concepts and tests results are commented. Finally, the challenge in detection and analysis of S&R is discussed. Objective and subjective evaluation methodologies are being developed and suppliers training and integration have been improved

Through computational dynamic simulations is possible to achieve high reliability index in the development of automotive components, thus reducing the time and component cost can generate significant levels of competitiveness and quality. This work suggests the validation of a methodology for simulation, able to predict and quantify the best design of the parking brake cable that although it is flexible, has in its structure composite elements of different mechanical properties. Known difficulty of mathematically predict nonlinear relationships deformation under forces and moments effect was first established, studies based on experimental measurements serve as input parameters for simulating the dynamic behavior of the flexible cable. With the aid of motion making use of NX9 CAD software, it was prepared the dynamic movement that the leaf spring suspension system does.

The globalization, rivalry and the technologies have changed the auto industry in a battlefield, where companies are fighting for quality, reliability, the reduction of development cycle and also cost. The manufacturing process of car body is the major responsible for time consumption, labor and investment. One of the bottleneck solutions is to use computational simulations during design phase in order to minimize the reworks. The car body is composed by several stamped parts, and its design requires a series of parallel activities, and one of the fundamental information is the accurate magnitude of spring back distortions, but due to the complexity of the phenomenon, the results are not so accurate as desired. The explored literatures are recommending numeric methods to simulate material's behavior and also the spring back phenomenon.

The development of fuel systems components are becoming challenging with the increasing use of Biofuels like Biodiesels and Ethanol around the world. Biodiesels are one of the most challenging fuels, once they can have multiple sources, which influences its characteristics, mainly the oxidization stability and peroxide levels. As the fuel characteristics changes along the time, the correct materials selection during the development phase is very important for the fuel system performance during the vehicle lifetime. One of the components most affected by the Biodiesel is the in tank fuel pump system. During the vehicle lifetime, it is exposed to all sorts of fuel and its contaminants and exposed to system stress factors like temperature and voltage variation. The wires insulation in the fuel pump systems are one of the most affected components.

The Brazilian Automotive regulations that are aimed towards the safety of drivers, passengers and pedestrians have gone through recent changes to prevent and/or minimize injury and trauma from different types of accidents. Until now, National Traffic Council (CONTRAN) Resolution n° 14/98 required vehicles to only have safety belts for an occupant restraint system, and frontal airbags were not required. Since the recent CONTRAN n° 311/09 Resolution requires mandatory frontal airbags, the occupant restraint system must be tuned due to the interaction with different components that may make up the system, like safety belts with pretensioners and seatbelt load limiting devices. The present study was developed to optimize the restraint system of a current vehicle in production, while focusing on minimizing the vehicle complexity. The optimization tool helped to develop a robust restraint system for the frontal passenger during a frontal impact [1].

Through computational dynamic simulations is possible to achieve high reliability index in the development of automotive components, thereby enabling the reduction of cost and time of a product development with considerable gain in quality. This work suggests the validation of a methodology for simulation where is possible to improve the confidence level for design flexible components, such Heater and Cooling hoses that are under dynamic engine action, in relation to the physical model. Known the difficulty in predicting non-linear mathematical relationship deformation under effect of forces and moments, was established a study based on experimental measurements where were used as input parameters to simulate the dynamic behavior of flexible components, in this case, coolant hoses.

Vehicle ergonomics, more specifically driver ergonomics, has been the subject of interest in the automotive industry as a way to provide customers vehicles that have more than modern project, efficiency and competitive price. The driver ergonomics is related to the way the driver interacts with the vehicle interior, particularly, with the seat, hand and foot controls, considering aspects such as ease of access, space, proper upper and lower limb motion and drivers comfort and fatigue. Regarding the lower limbs, the driver’s comfort can be evaluated in terms of joint moments and muscle forces, which are influenced by the hip, knee and ankle joint angles, which in turn depend on the distances between the seat and pedal. Variations in seat to pedal horizontal or vertical distances will result in different angular positions and, consequently, different joint moments and muscle forces, which are associated to greater or lower muscular activations and greater or lower driver’s fatigue.

Carbon canisters are used in gasoline passenger vehicle and light duty truck applications. The component is part of the vehicle emission control system. Activated carbon (also known as charcoal) traps hydrocarbon vapors from the fuel tank and vapors created during the fuel tank refueling and venting events. Canister design, charcoal type and performance have been driven by evaporative emission regulations around the world, and evaporative emission requirements have enhanced through the years. The trend of evaporative emission requirements in Brazil indicates the use of improved carbon canisters in the near future. Carbon canisters are needed to store hydrocarbons that would otherwise pollute the environment. Wood based activated carbon is manufactured from sawdust, which is a renewable resource. The result is a healthier earth on which we live. Figure 1 illustrates the activation process of carbon. Figure 1 Activation process of carbon.

Acoustics, in a broad sense, is an essential product attribute in the automotive industry, therefore, it is relevant to study and compare theoretical and numerical predictions to experimental acoustic measurements, key elements of many acoustic development processes. The numerical methods used in the industry for acoustic predictions are widely used for exhaust system optimization. However, the numerical and theoretical predictions very often differ from experimental results, due to modeling simplifications, temperature variations (which have high influence on speed of sound), manufacturing variations in prototype parts among others. This article aims to demonstrate the relevant steps for acoustics development applied in automotive exhaust systems and present a comparative study between experimental tests and computer simulations results for each process. The exhaust system chosen for this development was intended for a popular car 4-cylinder 1.0-liter engine.

Brazil, that presents one of the highest accidents indexes of the world, does not have any specific regulation related to the use of an external light during the day time which provides a better visibility of the vehicle in movement and according to studies gives more reaction time for the other road users. Many countries in Europe and North America shows good results since they adopted the lights on during the day with collision reduction of vehicle to vehicle, vehicle to pedestrian and vehicle to cyclists. The aim of this study is to show the benefits of the Daytime Running Lights (DRL) and its relation to the reduction of the traffic accidents, as well as a brief analysis on the use of a dedicated system, which can be more efficient since it can be designed to provide a light distribution allowing a better visibility as possible.

This paper explores the method of modeling and validation the computational tools able to accurately replicate the dynamic behavior of a Formula SAE vehicle. Based on limitations in conducting physical tests, it is possible to mathematically predict the forces and momentum generated on the steering column of the vehicle, minimizing effort and improving driver comfort even before the component physically manufactured. The results in permanent state due technical instrumentations were used in the physical vehicles and compared with other proposals (skid Pad test). As the software simulating the same path, it was possible to adopt values of speed and wheel steering, allowing compare the dynamics of the vehicle, through the signals from other sensors installed in the data acquisition system, validating the behavior of the models presented in permanent state. Other aspects were studied to understand vehicle behavior concerning lateral stability and steering behavior.

Rear underride crashes are responsible for thousands of deaths every year in Brazil. To support the fight against this calamity, it was design and tested an articulated guard able to avoid car underride. Because of its articulation capability, this guard can be placed as low as necessary without impairing the truck maneuverability. Crash tests were carried out with the new guard and with another one constructed according to Brazilian standards. The articulated guard was able to avoid underride of a vehicle GM Corsa colliding at 50 km/h in offset of 50%. The other guard could not avoid underride under the same test conditions.

Nowadays the automotive market is reducing product development time and launching more technological vehicles, always focusing on having even more safety with better customer experience which generates big competitiveness and requires more accurate and faster development, the virtual simulations make it possible to meet this new reality with a high confidence level. This work comprises the validation of a methodology to analyze the design confidence level for flexibles associated with suspension kinematics. To validate the methodology, the scanned physical model was compared with the virtual simulations using the Simcenter 3D Flexible Pipe software. As inputs data for simulation, it is used geometrical, physical, and chemical information. Through the suspension kinematics study was establish possible movement situations to obtain the flexibles deformations attending to all suspension positions.

Rollover crashes are responsible for more than 20% of total passengers deaths in vehicular accidents. Every year a higher number of consumers have been critically injured in rollovers, which translates into hundreds of millions of dollars of unnecessary health care cost. Efforts to reduce the incidence of death and catastrophic injuries associated with rollover crashes have increased the importance of both, prototype testing and computational simulations. Automotive industry and individual researchers have performed numerous rollover tests using instrumented anthropomorphic test devices (ATD), with the objective of predicting possible head, neck, and cervical spine injuries. Some of these works measured accelerations, forces and moments on head, neck and cervical spines, which can cause several other injuries according to medical traumas databases.