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Plastics injection molds are typically subjected to a combination of loadings such as injection pressure, temperature changes, clamping force, and potential interference at seal-off surfaces during manufacturing process. The loadings on the molds are as cyclic as the injection molding cycles. As a result, the molds could fail either in material overstraining or fatigue. In this paper, several failure cases will be presented, along with the FEA stress and fatigue analysis results, to demonstrate the effect of the above mentioned loadings on the mold structural integrity. This paper will also show how the FEA stress and fatigue analyses were effectively employed to determine the mold failure root cause and assist the design modification in a usually constrained time frame.

The demand for a fuel cell as a clean energy source will increase significantly in the automotive and home appliance field. Structural steels (especially, spring steels ), used under high hydrogen pressure in the fuel cell may cause hydrogen embrittlement and delayed fractures; therefore, there is a strong demand for the development of new materials which have excellent resistance to hydrogen embrittlement. The authors have developed an austenitic stainless steel spring wire that maintains high fatigue strength even after hydrogen absorption

A method is described which permits the design of a four stroke, spark ignition engine to an expansion ratio arbitrarily greater than the compression ratio, and the operation of this engine at WOT at all but the lowest power outputs. A test engine employs modified fixed intake valve timing, an intake manifold with a reed valve, plenum, and plenum control valve, and reduced cylinder clearance volume. An independent laboratory compared the test engine to an unmodified stock engine at equal power. The test engine demonstrates a BSFC advantage (up to 36% at idle) when compared to the stock engine at partial throttle.

This paper presents a variable compression ratio (VCR) system that has a new piston-crankshaft mechanism with multiple links. This multi-link mechanism varies the piston position at top dead center (TDC), making it possible to change the compression ratio of the engine continuously. Previous attempts have been made to achieve variable compression ratio with this type of method, but it was difficult to avoid various undesirable effects such as an increase in the engine size, substantial weight increases, increased engine block vibration due to a worsening of piston acceleration characteristics and increased friction resulting from a larger number of sliding parts. At the stage of developing the basic design of the multi-link geometry, emphasis was placed on selection of a suitable link geometry and optimization of the detailed dimensions with the aim of essentially resolving these previous issues.

A new generation Northstar DOHC V8 engine has been developed for a new family of rear-wheel-drive (RWD) Cadillac vehicles. The new longitudinal engine architecture includes strategically selected technologies to enable a higher level of performance and refinement. These technologies include four-cam continuously variable valve timing, low restriction intake and exhaust manifolds and cylinder head ports, a steel crankshaft, electronic throttle control, and close-coupled catalysts. Additional design features beyond those required for RWD include optimized block ribbing, improved coolant flow, and a newly developed lubrication and ventilation system for high-speed operation and high lateral acceleration. This new design results in improved performance over the entire operating range, lower emissions, improved fuel economy, improved operating refinement, and reduced noise/vibration/harshness (NVH).

The extent to which the stress history of a component is non-proportional and out-of-phase can strongly influence the accuracy of the fatigue-life prediction. Phenomenological multiaxial fatigue models are more or less accurate depending upon the extent to which the stress or strain history is non-proportional and out-of-phase. Herein, scalar measures are introduced for characterizing the non-proportional and out-of-phase extent of any stress or strain history. These scalar measures are used to characterize the stress history of a an overhead-cam cylinder-head when subjected to severe cyclic operating thermal loads.

The present work was intended to increase the rolling-contact fatigue life of the crank pin for a motorcycle. The small motorcycle uses a needle roller bearing at the big end of the connecting rod. The needle roller exerts high Hertzian stress on the crank pin. This stress sometimes causes rolling-contact fatigue failure such as pitting. The contaminated oil accelerates the rolling-contact fatigue failure. In order to increase the life of the crank pin, not only the quality of the steel but also the casehardening treatment plays an important role. In the present work, a high quality Cr-Mo steel containing oxygen concentration below 10 ppm was chosen as the base steel. The rolling-contact fatigue life was compared in four types of casehardening: normal carburizing, carbonitriding, super-carburizing and super-carbonitriding. A thrust-type testing machine was used during these comparison tests.

A research project has been completed to determine if commercially available blue coated lamps provide visual benefit for nighttime driving over standard tungsten halogen lamps. As an esthetic option, tungsten halogen lamps with an absorptive coating have been developed to mimic the appearance of HID lamps. The transmission of these coated lamp results in a continuous output spectrum, like standard tungsten halogen, but with a lower “yellow” content, giving an appearance similar to HID lamps. Aside from esthetic reasons for using blue coated lamps, there is also evidence that the spectral output may provide visual benefits over standard tungsten halogen lamps in nighttime driving. While driving at night, off-axis or peripheral vision is in the mesopic response range and the eye's sensitivity shifts towards shorter wavelengths or “blue” light.

Locati method is suitable in preliminary fatigue tests and production quality control. It is efficient since it uses just one test sample. The method requires that the slope of the S-N curve be known a priori, however. In this paper, a modified Locati method is presented that virtually eliminated this requirement. The method produces a point on the S-N plane that is independent of the slope of the S-N curve. The test design strategy to control the fatigue life of such a point is provided. The presented method has been successfully applied to preliminary fatigue tests of several welded components of ground vehicles.

A transient nonlinear Finite Element Analysis (FEA) method has been developed to simulate the inelastic deformation and estimate the thermo-mechanical fatigue life of cast iron and cast steel exhaust manifolds under dynamometer test conditions. The FEA uses transient heat transfer analysis to simulate the thermal loads on the manifold, and includes the fasteners, gasket and portion of the cylinder head. The analysis incorporates appropriate elastic-plastic and creep material models. It is shown that the creep deformation is the most single critical component of inelastic deformation for cast iron manifold ratcheting, gasket sealing, and crack initiation. The predicted transient temperature field and manifold deformation of the FEA model compares exceptionally well with two experimental tests for a high silicon-molybdenum exhaust manifold.

In order to improve automotive headlamp visibility, it is important to conduct visibility evaluation technology while a vehicle is running. Our own evaluation technology in motion has been established according to two points of view; creating evaluation objects and developing evaluation methods. This paper deals with the results of the investigation, and its' effectiveness for AFS, by using this evaluation technology.

Many attempts have been made to improve automotive brake cooling by increasing the pumping action of vented brake rotors, both experimentally and using computational fluid dynamics. Testing of these improvements has occurred by measuring the airflow at the outlet of a rotating brake rotor in still air, however this is a vastly different environment to the actual working condition of the rotor. Airflow around the rotor, as a result of the forward movement of the vehicle, will have a considerable effect on its pumping ability. In this paper a comparison is made between the measured airflow through a straight-vane vented disc: (1) isolated disc still air; (2) disc in still air with the wheel on; (3) disc in moving air with the wheel on; and (4) on road simulation using a ¼ car. Both time-averaged and real-time measurements are presented. In the still air tests results showed a linear relationship between rotational velocity and airflow through the disc.

This paper presents the mathematical and lighting models of the FF (Free Form) ellipsoidal projector with an MPXL discharge light source. The use of models based on “elementary reflection” has been suggested for lighting calculations. The light intensity in the specific direction of projector's space has been determined by the “reverse ray test”, which makes possible determination of the shape of the “Figure of The Bright Points” and luminance distribution inside the figure. The procedures presented below facilitate development of computer programs for projector modelling and calculations.

This paper investigates the effect of ambient temperature on the performance characteristics of an automotive poly-rib belt operating in an under-the-hood temperature environment. A three-dimensional dynamic finite element model consisting of a driver pulley, a driven pulley, and a complete V-ribbed belt was constructed. Belt tension and rotational speed were controlled by means of loading and boundary inputs. Belt construction accounts for three different elastomeric compounds and a single layer of helical wound reinforcing cord. Rubber was considered as hyperelastic material. Cord is linear elastic. The material model was implemented in ABAQUS/Explicit for the simulation. Analysis was focused on rib flank and tip since stress concentrations in these regions are known to contribute to crack initiation and fatigue failure.

The paper describes a unique rating method for the quality of headlamp light distributions with respect to homogeneity. Homogeneity is a significant measure of the quality of light distributions for automotive headlamps. As a factor for headlamp design homogeneity has long been neglected. In a unique trial involving 124 test-persons and 21 different sets of headlamps a vast amount data was collected and evaluated. Measurement data for the road illumination, subjective judgment and experimental data was correlated to form a definition of headlamp quality. The findings show, that different areas of the headlamp beam pattern are relevant depending on the overall adaptation level. The results gathered by the study now provide a better basis for headlamp design and may in future lead to a more widely accepted headlamp rating.

Modern engines are designed to operate at highly rated engine speed and load, which brings up challenges to the lubrication design of main and connecting rod bearings. Damages could occur on rod bearings due to high-speed relative sliding motion. Expensive cross drillings are often seen in today's engineering practice to ensure adequate lubrication in rod bearings. The objective of this study is to establish a methodology for predicting lubrication flows in rod bearings and use it to guide the engineering design. The high-speed nature of the crankshaft makes it difficult to acquire experimental data during its normal operation for better understanding the flow inside rod bearings and oil circuits. In the present study, the commercial CFD code, FLUENT, has been used to evaluate the flow characteristics within the rod bearings and oil passages connecting main bearing to rod bearing.

One of the ways to represent the crankshaft in a 3D engine dynamic simulation is by using structured model consisting of nodes and binary elastic elements. The paper presents a methodology for automatic generation of this kind of models, starting from CAD data. The main advantage of the method - implemented as a software tool - is a significant reduction in time to model the crankshafts, and hence the overall project time. The calculation results show a good correlation with those obtained by commonly used FEA software.

In vehicle-pedestrian impact, the majority of pedestrian fatalities are caused by head injuries. Accident analysis showed that bonnet of car often had consequences with severe head injuries in accidents involving young pedestrians. Important factor involving risk of head injury is design of bonnet structure. The injury risks to the head by such an impact were examined by child headform impact test. HIC value and deformation were the main criteria for assessing of bonnet pedestrian friendliness. Different bonnet modifications were examined using mathematical simulation of such a test and their benefit for child head injury risk reduction was assessed.

The automotive industry is focusing more on protection of pedestrians and cyclists. Approximately 6000 out of every 35 000 persons killed in traffic accidents annually in the European Union are pedestrians. Therefore the development of passive measures to improve pedestrian safety is strongly supported by the European automotive industry. This paper describes in detail the mechanics and kinematics of an active hood. Furthermore the investigation of the integration and effects of the active hood in a feasible safety concept of modern cars is presented. Additionally, detailed evaluations of real hardware testing and simulation of pedestrian head impact are shown in this paper. The results are discussed, and some new information will be brought up for future strategies in safety concepts for new cars.

Several research studies have concluded that light trucks and vans (LTVs) are incompatible with cars in traffic collisions. These studies have noted that crash incompatibility is most severe in side crashes. These early research efforts however were conducted before complete introduction of crash injury countermeasures such as dynamic side impact protection. Based upon U.S. traffic accident statistics, this paper investigates the side crash compatibility of late model cars, light trucks and vans equipped with countermeasures designed specifically to provide side crash protection. The paper explores both LTV-to-car crash compatibility and crash incompatibility in car-to-car collisions.