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A newly developed cross flow cylinder head has been used for comparison between throttled and unthrottled operation using late intake valve closing. Pressure measurements have been used for calculations of indicated load and heat-release. Emission measurements has also been made. A model was used for estimating the amount of residual gases resulting from the different load strategies. Unthrottled operation using late intake valve closing resulted in lower pumping losses, but also in increased amounts of residual gases, using this cylinder head. This is due to the special design, with one intake valve and one exhaust valve per camshaft. Late intake valve closing was achieved by phasing one of the camshafts, resulting in late exhaust valve closing as well. With very late phasing - i.e. low load - the effective compression ratio was reduced. This, in combination with high amount of residual gases, resulted in a very unstable combustion.

Homogeneous-Charge-Compression-Ignition (HCCI) engine operation in a vehicle drive cycle is a very dynamic process. In this paper, a controller is devised on the premise that the vehicle is operating under Drive-By-Wire so that the driver commands the engine torque output according to the perceived vehicle speed. Thus a load-following controller is appropriate. Such a controller was developed for a single cylinder engine with electromagnetic variable valve timing control (also known as Controlled-Auto-Ignition (CAI) operation). Under open-loop operation within the CAI regime, the results indicated that the engine response was bipolar in nature: (a) the engine either responded quasi-statically to the open-loop control, or (b) the CAI combustion failed. The latter happened in a load increase process in which the per-cycle increment was too high.

New devices and control techniques have been adopted to take advantage of variable valve timing properties to improve engine performance or load control. This paper presents a study focused on engine load control strategies associated with early intake valve closing or late intake valve closing. It can be shown that these load control modes can improve the indicated thermal efficiency of the engine as compared with the conventional throttle control. These strategies are sometime called Miller cycle or Atkinson cycle, since the real compression ratio becomes smaller than the expansion ratio. A thermodynamic spark-ignition engine simulation model was employed. The advantage of a simulation model is to conduct parametric studies without the need of complex experimental apparatus. In this way, a deep understanding of the physical phenomena can be achieved and the sole effect of the desired parameter can be shown.

The seat belt system is one of most important component of the safety instrument family in a vehicle. The main purpose of seat belt is to minimize the injuries by preventing the occupant from impacting hard on interior parts of the vehicle and also the passenger from being thrown-out from the vehicle in case of rollover accidents. The standard three-point belt is mounted in the vehicle at three locations namely Anchor, D-ring and Buckle. The position of anchorages is very important to distribute the impact load evenly to the occupants. Very high load in any of these locations could cause breakage of the mountings and also concentrated loading on the occupant chest of pelvis. Current study mainly focuses on the seatbelt assembly performance improvement against UNECE-R16 sled test. The sled test was carried out first using 28g peak acceleration pulse and measurement of forces at shoulder and anchor position was measured using the load cell.

This paper presents a load distribution-specific viscoelastic structural characterization of the Hybrid III 50th percentile male anthropomorphic test dummy thorax. The dummy is positioned supine on a high-speed material testing machine and ramp-and-hold tests are performed using a distributed load, a hub load, and a diagonal belt load applied to the anterior thorax of the dummy. The force-deflection response is shown to be linear viscoelastic for all loading conditions when the internal dummy instrumentation is used to measure chest deflection. When an externally measured displacement (i.e., a measurement that includes the superficial skin material) is used for the characterization, a quasilinear viscoelastic characterization is necessary. Linear and quasilinear viscoelastic model coefficients are presented for all three loading conditions.

Newly developed small-size power relays are described and their test results on switching load durability are presented. They are half the case volume compared to plug-in low-profile ISO Microrelays. Test temperature for the relays was 120 °C keeping in mind engine room conditions. Operation voltage was 14 V. Contact resistance of the normally-open type kept stable values ranging from 3 to 4 mΩ in lamp load tests (11 A, 300k cycles) and in horn load tests (11 A, 150k cycles). Contact resistance in the transfer (change-over) type kept stable values ranging from 3 to 9 mΩ in windshield wiper motor load tests (8 A, INT operation, 600k cycles).

The source in an intake/exhaust system is commonly modeled as a source strength and impedance combination. Both the strength and impedance are normally measured and measurement accuracy depends on selecting an appropriate acoustic load combination. An incident wave decomposition method is proposed which is based on acoustic wave decomposition concepts instead of an electric circuit analogy providing a more straightforward approach to investigating the effect of acoustic load selection. Based on studying wave reflections in the system, the uncertainty for determining source impedance is estimated.

A spark-assist homogeneous charge compression ignition (SA-HCCI) operating strategy is presented here that allows for stoichiometric combustion from 1000-3000 rpm, and at loads as high as 750 kPa net IMEP. A single cylinder gasoline engine equipped with direct fuel injection and fully variable hydraulic valve actuation (HVA) is used for this experimental study. The HVA system enables negative valve overlap (NVO) valve timing for hot internal EGR. Spark-assist stabilizes combustion over a wide range of engine speeds and loads, and allows for stoichiometric operation at all conditions. Characteristics of both spark-ignited combustion and HCCI are present during the SA-HCCI operating mode, with combustion analysis showing a distinctive spark ignited phase of combustion, followed by a much more rapid HCCI combustion phase. At high load, the maximum cylinder pressure rise rate is controlled by a combination of spark timing and retarding the intake valve closing angle.

The performance of a structural design significantly depends upon the assumptions made on input load. In order to estimate the input load, during the design and development stage of the suspension assembly of a BAJA car, designers and analysts invest immense amount of time and effort to formulate the mathematical model of the design. These theoretical formulations may include idealization errors which can affect the performance of the car as a final product. Due to the errors associated with the assumption of design load, several components might have more weight or may have less strength than needed. This discrepancy between the assumed input load (lab or theoretical studies) and the actual load from the environment can be eliminated by performing a real life testing process using load recovery methodology. Commercial load cells exist in industry to give engineers insight to understanding the complex real world loading of their structures.

The need for clear definition of accuracy performance and operating criteria for Load Indicating Systems has been voiced by crane operators, crane manufacturers, and legislative agencies. A thorough study of the existing Recommended Practice was undertaken with the specific goal to upgrade J-376 to permit greater understanding of the minimum performance requirements of Load Indicating Systems.

The majority of fatigue crack growth (FCG) data associated with load interaction effects have been interpreted in terms of plasticity effects at the crack wake. This paper presents a new approach by which the FCG behavior for different R-ratios can be predicted using the master curve. In this approach, the stress intensity factor (SIF) range, ΔK, is normalized in terms of ΔK at R=0. The corresponding mean value of SIF, Km, is normalized by the SIF amplitude, Ka. A curve is plotted for this normalized SIF data, which collapses all the R-ratios into a master curve and therefore enables the prediction of other R-ratios. From the analyses of different materials taken from literature it is demonstrated that the master curve approach is very effective in predicting the R-ratio effects on fatigue crack growth behavior.

An important component in many hybrid electric vehicle (HEV) concepts is the load leveling device (LLD). The best type of LLD for HEVs is under debate. This paper identifies the important concept selection criteria for the three leading types of LLDs being considered for use in HEVs. The performance of electrochemical batteries, ultracapacitors, and flywheels is compared using these criteria. The concept selection methodology indicates that at the present time flywheels show the most promise for development for use in a hybrid electric vehicle. The use of this type of selection methodology is a powerful tool in identifying concepts worthy of development as well as determining performance criteria in need of improvement within each concept.

A novel 2-zone combustion system was examined at medium load operation consistent with loads in the light duty vehicle drive cycle (7.6 bar BMEP and 2600 rev/min). Pressure rise rate and noise can limit the part of the engine map where pre-mixed combustion strategies such as HCCI or RCCI can be used. The present 2-zone pistons have an axial projection that divides the near TDC volume into two regions (inner and outer) joined by a narrow communication channel defined by the squish height. Dividing the near TDC volume provides a means to prepare two fuel-air mixtures with different ignition characteristics. Depending on the fuel injection timing, the reactivity of the inner or outer volume can be raised to provide an ignition source for the fuel-air mixture in the other, less reactive volume. Multi-dimensional CFD modeling was used to design the 2-zone piston geometry examined in this study.

Premixed diesel combustion is intended to supplant conventional combustion in the light to mid load range. This paper demonstrates the operating load limits, limiting criteria, and load-based emissions behavior of a direct-injection, diesel-fueled, premixed combustion mode across a range of test fuels. Testing was conducted on a modern single-cylinder engine fueled with a range of ultra-low sulfur fuels with cetane number ranging from 42 to 53. Operating limits were defined on the basis of emissions, noise, and combustion stability. The emissions behavior and operating limits of the tested premixed combustion mode are independent of fuel cetane number. Combustion stability, along with CO and HC emissions levels, dictate the light load limit. The high load limit is solely dictated by equivalence ratio: high PM, CO, and HC emissions result as overall equivalence ratio approaches stoichiometric.

The load path U* analysis is an effective tool for investigating the load paths in body structures. In the present study, a new index U** is introduced to investigate structures under distributed loading. The new parameter U** is a complementary concept of U*. Although the conventional index U* cannot be applied to cases of distributed loading conditions, the new index U** can be applied to those cases. This paper describes the application of a load path U** analysis to improve efficiently the first eigenvalue of the vertical bending mode in a vehicle body structure model. It also explains how target parts for shape optimization are interpreted on the basis of a load path U** analysis when a load is applied to reproduce the first vertical bending mode.

Heavier, larger pickups and SUVs are bound to encounter lighter, smaller passenger vehicles in many future accidents. As the fleet has evolved to include more and more SUVs, their frontal structures are often indistinguishable from pickup fronts. Improvements in geometric compatibility features are crucial to further injury prevention progress in side impact. In corner crashes where modern bullet passenger car (PC) bumpers make appropriate geometrical overlap with target PC rocker panels, concentrated loads sometimes disrupt foam and plastic bumper corners, creating aggressive edges. In situations where sliding occurs along the structural interface, these sharp edges may slice through doors, panels and pillars. End treatments for such bumper beams should be designed to reduce this aggressive potential.

A new concept, a parameter U*, is introduced to express load transfer in a structure. Two cases of U* analysis for a floor structure of a passenger compartment are examined. In the first case, three conditions of U* are introduced as objective functions, and GA structural optimization is applied. The emergent floor structure after the GA calculation has a unique shape in which a member connects the frontal part of an under-floor member and the rear part of a side-sill. In the second case, the U* values and the load paths in a floor structure under collision are calculated by use of PAM-CRASH. As the collision progresses, the under-floor member becomes the principal load path, and in the final stage of the collision the roll of the under-floor member becomes dominant.

The problems of restraining miscellaneous loads in light vans and passenger cars derivates were quantified with a view to developing specifications for strong anchorage points, bulkheads, racking, and restraint systems. The project brought together the main organisations involved: the fleet operators, vehicle manufacturers, restraint manufacturers, and racking manufacturers. In an information gathering phase, the type of accidents were defined against which the restraint system would be required to provide protection. The specified accidents were simulated using barrier crash tests and dynamic sled tests. The test vehicles were equipped with bulkheads and storage bin systems. Various schemes of loads were held down with webbing restraints attached to anchorage points. This test work, as well as providing the loading information for the restraint specification, also indicated the performance given by existing systems.

A simple spool valve combined with load sensing principles is used for precision flow control on demand. This type of valve, even though it has been in use for about ten years, received new attention during the energy crunch of 1974 and the subsequent interest in load sensing systems The load sensing flow control has been used on many applications and especially for power steering circuits where priority flow is needed. The valve functions in all systems: open center, closed center, and load sensing. It provides flow and pressure to a controlled circuit on demand (only as much as needed). This paper describes the function and some applications of the valve and includes system considerations. Generally, a fluid linked power steering system is used for illustration but the same principles can apply to any circuit using a special four way valve.

Energy conservation was accomplished by combinating a variable volume flow and pressure compensated piston pump with a standard fixed displacement gear pump with Cross 6LR load response valve assembly. This system as designed can be used on mobile equipment with hydraulic systems to 80 GPM cap.