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Cleaner steels, advanced manufacturing techniques and the use of modern design methods have justified an increase of dynamic load ratings for cylindrical and tapered roller bearings as well as ball bearings. With the new load ratings, greater emphasis must be placed on the operating factors that influence the fatigue life of a bearing. These factors include reliability, material, lubrication, alignment and load distribution. A detailed discussion of load rating increases and the life adjustment factors is presented.

The aim of this paper is to demonstrate the methodology to simulate the induced stresses/strains due to thermo-mechanical loading of automobile brake drum.. The brake drum undergoes mechanical load due to applied brake pressure and thermal load due to friction generated between brake pad and brake drum while brake is applied. This coupled thermo-mechanical loading affects the life of the brake drum as the stiffness of the brake drum is reduced. The conventional method of simulating this problem is done using Lagrangian discretization in which the load is applied and inertia effect due to angular velocity is applied to a drum at static condition. In contrast, in this paper Eulerian discretization is adopted for finite element analysis, in which drum brake model is discretized as spatially dependent that facilitates actual rotation of brake drum with simultaneous application of brake load resulting more precise simulation.

Cyclic loading is defined as external loading that varies within the revolution of a bearing and is repeated for every revolution. The cyclicly varying loads may consist of a series of discrete loads that occur in a repeating pattern or a continuously varying force or a combination of these. A simple example of cyclic loading is a single cylinder, double acting piston pump in which the force on the bearings reverses every 180° of a revolution; as a result, the same half of the rotating bearing race passes under the load twice in a single revolution. More complex patterns of cyclic loads occur in rotary engines, fuel injection pumps, nutating engines, etc. The paper presents the theoretical relationships and methods that predict the effect of cyclic loading on the fatigue life of anti-friction bearings. An example problem solved with the aid of a special analysis program illustrates the results from these methods.

Tractors are the self-propelled vehicle which finds its major application in agriculture, haulage and construction equipment. The product development cycle time of a tractor is more as compared to automobiles since it has to undergo rigorous field testing. Bringing more realistic component and system level validation in the test lab will drastically reduce the product development cycle time. Non-availability of standard usage pattern and customer-correlated proving ground pose a bigger challenge for bringing the field conditions to the lab. As a result, the tractor has to be instrumented with sensors and load-time history needs to be acquired as per real world usage pattern. Raw data from the field cannot be used directly for lab testing since the number of load cycles will be very high. Raw data have to be edited based on damage calculation and fatigue sensitivity analysis technique.

A number of service fatigue history summarization statistics are examined for their suitability in regenerating the history in the laboratory. Evaluation criteria applied include: fatigue damage-per-level equivalence, implementation simplicity, waveform similarity, and fatigue life equivalence. The results suggest that a three-dimensional “From-To” matrix that includes sequence information about the original variable amplitude histories, is optimal for service history reconstruction.

Fatigue in crane with particular reference to offshore cranes is briefly discussed, and field measurement records illustrating types of vibration experienced in crane structures are shown. Design rules against fatigue in a couple of recognized Crane standards are discussed. It is pointed out that these standards might be inadequate in the evaluation of fatigue in cranes. A modified procedure for evaluation of fatigue in offshore crane elements is pointed out. The method description is provided with data which should make practical evaluations possible. The material presented is not authorized and is only to be regarded as a contribution to the current research in this field.

This paper introduces a unified framework to perform fault tracking based on a technology-independent and consistent generic functional model capable of representing the entire automotive system while maintaining the ease of use. Based on the example of a complete light function model of a luxury class vehicle, it is illustrated how certain failures such as device break down or signal faults propagate through different subsystems and how these failures can be tracked. Another key feature of the proposed dependency analysis method is its valuable contribution to an efficient change management in the design phase. Given the functional model of the system, a tool can be used to indicate which development departments and resources are affected of possible changes and which are not.

This paper presents a fault-tolerant control (FTC) algorithm for four-wheel independently driven and steered (4WID/4WIS) electric vehicle. The Extended Kalman Filter (EKF) algorithm is utilized in the fault detection (FD) module so as to estimate the in-wheel motor parameters, which could detect parameter variations caused by in-wheel motor fault. A motion controller based on sliding mode control (SMC) is able to compute the generalized forces/moments to follow the desired vehicle motion. By considering the tire adhesive limits, a reconfigurable control allocator optimally distributes the generalized forces/moments among healthy actuators so as to minimize the tire workloads once the actuator fault is detected. An actuator controller calculates the driving torques of the in-wheel motors and steering angles of the wheels in order to finally achieve the distributed tire forces. If one or more in-wheel motors lose efficacy, the FD module diagnoses the actuator failures first.

The problem of synchronizing several loads has been the subject of many studies over the past few years. Some of the authors have been involved in the design of high precision flow divider/combiner valves which are accurate to 99% over large pressure and flow ranges. The disadvantage of these designs lies in their inflexibility in terms of varying flow with complete independence to the various loads. Traditional approaches to the multi-load problem have been to use velocity or flow feedback signals to several electrohydraulic valves to obtain independent action. In this paper, the authors introduce the feasibility of using a single rotary type valve to provide a pulse width modulated flow pulse to each circuit. A model of the basic concept was used to establish the feasibility of the approach using simulation studies. A possible valve configuration to implement the concept is presented.

This paper summarizes the results of a study to examine the feasibility of a system safety monitor (SSM) for application to the trucking of hazardous materials. The concept is to provide a continuous record of truck and safety system operation and to detect the onset of certain critical situations. Although originally developed with respect to liquified natural gas trucking, the basic technology, with suitable modification, is applicable to trucks carrying other types of cargo. In developing the SSM concept, five critical accident scenarios were established following a statistical analysis of accident data and a series of interviews. To minimize the required measurements and instrumentation, a theoretical analysis of truck dynamics was performed to develop a set of directly measurable quantities which are sufficient to indicate the occurrence of the selected scenarios.

A general model, which uses general equations to determine the thermophysical properties of fuels in terms of temperature, molecular mess, critical constants and molecular structure, has been developed to describe the evaporation characteristics of multicomponent fuel droplets according to both the shell and ideal solution postulates. Upon applying this model to alcohol-dodecone mixtures, the feasibility of such mixtures for heterogeneous combustion systems has been assessed, and feasibility charts have been developed.

Many patents and devices exist which purport to prevent or inhibit “jackknifing” of tractor-semitrailer vehicles. The feasibility of such anti-jackknifing systems (AJS), specifically those which are located about the fifth wheel of tractor semitrailers was investigated. Through computer simulation the characteristics of jackknife and trailer swing were identified. Methods of controlling articulation in a jackknife generally produced favourable results. When the same AJS was applied to trailer swing conditions, the swing instability was usually increased rather than decreased. These results lead to the conclusion that efforts should be concentrated on devices for controlling or preventing a jackknife from occurring while maintaining a more or less neutral affect on swing.

This paper discusses the feasibility of electrifying medium to heavy urban goods distribution trucks. As a case study, an existing transport system in the Swedish city of Gothenburg is used. The project is a joint research effort between a vehicle OEM, an electric utility, a fleet operator, the Swedish Transport Administration and two research organizations. One main objective is to determine if and when different electrified powertrains are cost efficient to the end user. The results indicate that by 2015 conventional powertrains are still probably the most cost effective alternative in all applications studied. But in 2025, electrified powertrains are most cost efficient for most transport scenarios. These results indicate a transition in preferred powertrain technology for urban trucks within the coming ten years. It is important to point out that this result may not be general.

A portable remote sensing system capable of real-time detection of particulate emissions from heavy-duty vehicles is being developed. The remote sensing technique employs optical extinction to measure the concentration of the carbonaceous fraction of the particulate matter and the CO2 in the exhaust plumes from individual vehicles. From these two measurements, instantaneous emission indices giving the mass of soot emitted to the amount of fuel burned by the vehicle at the given operating condition can be computed. Two tests designed to characterize the accuracy of the technique were conducted: 1) measurements through an exhaust plume from a laboratory diesel using a sequence of steady-state operating conditions; and 2) measurements of transient emissions from full size diesel-powered buses whose emissions were simultaneously measured in a full-scale dilution tunnel. In both cases, the remote sensing measurements were in good agreement with those obtained by conventional methods.

In this paper, interior noise of a heavy commercial truck was modeled with the room equation. This approach assumed that large truck cabins may be adequately modeled as a practical room as is done in architectural acoustics, where ray theory and statistical concepts are suitable, and where application of complicated wave theory may not be necessary. This simplifies computational requirements, making a semi-empirical scheme useful for timely product development. This study employed sound power measurements at thirty-four surface patches encompassing the interior cabin boundary. Each surface-patch constituted an individual interior noise source. Predicted and measured results correlated well, demonstrating the capability to estimate driver-position noise level from predicted periphery sound intensity changes.

The Global trend to reduce toxic emissions associated with the expansion of Diesel engines usage led to the implementation of new regulations aimed at the reduction of diesel engine emissions. Since 2012, the PRONCONVE P7, which mandates a reduction in NOx emissions, has been in place in Brazil. Therefore, heavy duty vehicle manufacturers had to implement an after treatment system in new vehicles, where an aqueous urea solution (ARLA 32 in Brazil or AdBlue in some other countries) is injected into a Selective Catalytic Reduction (SCR) system to convert NOx gases into N2 and water. The Arla 32 is stored in a tank which needs to be periodically refilled at gas stations. As the ARLA 32 is an aqueous solution with no characteristic odor or color, it can be easily adulterated without any visible sign.

Automatic manufacturability analysis of injection moldings, sheet metal castings, stampings, forgings, etc., using knowledge-based heuristics depends on shape features, which are abstractions of the three dimensional (3D) geometric model of the parts. Conventional CAD systems do not explicitly contain shape feature information, therefore such information needs to be extracted from them. So far, extraction of shape features has been restricted to models with simple geometric shapes such as planar, cylindrical or conical shapes. Extending shape feature extraction to non-linear geometric models will allow Design For Manufacturability (DFM) analysis of non-linear models. This paper presents an approach to extract features from non-linear geometric models. The approach is based on abstract geometric entities called C-loops. The formation of a C-loop depends on a geometric entity called a silhouette. The C-loops are derived from the silhouette boundaries of an object.

A two-stroke Atkinson cycle engine is described. The engine has uniflow stratified mixture scavenging with a variably phased spherical rotary valve in the cylinder head and exhaust ports in the cylinder wall. These features combined in this configuration result in reduced fuel consumption, higher specific power output, less vibration, and smooth part load operation albeit increased size and cost compared to simple two-stroke engines used in power tools.

This paper seeks to answer questions pertinent to Federal regulations of noise in agricultural and off-highway equipment. It discusses the statutes under which authority lies, and whether or not the regulations actually accomplish the purposes for which they are intented.

This presentation shows the concepts and the advantages of the Fendt Vario CVT and the features that have been developed to enhance its use in agricultural tractors. The Fendt Vario transmission has been in production for more than 10 years with more than 60,000 tractors built with this CVT concept (until the first half of 2007, Fendt and OEM). As examples emphasize, the CVT helps to optimize the usable power and the fuel economy - especially when compared to power shift transmissions. The machine productivity is further improved by a variety of features like cruise control or constant engine speed for PTO operation with variable ground speed. Acceleration rates are adjustable and reversing can be accomplished with best operator comfort. Further automation and operation systems make the CVT tractor fit to high-end applications. A macro-instruction system allows the driver to store multiple operations.