It is accepted that defective structural designs are mostly caused by insufficient knowledge of input data, such as material properties or loading, rather than inadequate analysis or testing methods. In particular, loads associated with automotive and transport (trucks, trailers, containers, trains) structures are nontrivial to quantify. Such loads arise from stochastic and ill-defined processes such as driver/operator actions and structure-terrain interaction. The fundamental processes involved with the determination of input loading are measurements, surveys, simulation, estimation and calculation from field failures. These processes result in design criteria, code requirements and/or testing requirements. The present study deals with methods for the establishment of input loading for automotive and transport structures. It is attempted to generalise and unify new and existing techniques into a cohesive methodology. This is achieved by combining researched current theory and best practices, with lessons learned during application on, as well as new techniques developed for, a number of complex case studies, involving road tanker vehicles, light commercial vehicles, industrial vehicles, as well as tank containers. Apart from the above, the present study offers four individual, unique contributions. Firstly, two methods, widely applied by industry, namely the Remote Parameter Analysis (RPA) method, which entails deriving time domain dynamic loads by multiplying measured signals from remotely placed transducers with a unit-load static finite element based transfer matrix, as well as the Modal Superposition method, are combined to establish a methodology which accounts for modal response without the need for expensive dynamic response analysis. Secondly, a concept named Fatigue Equivalent Static Load (FESL) is developed, where fatigue load requirements are derived from measurements as quasi-static g-loads, the responses to which are considered as stress ranges applied a said number of times during the lifetime of the structure. In particular, it is demonstrated that the method may be employed for multi-axial g-loading, as well as for cases where constraint conditions change during the mission of the vehicle. The method provides some benefits compared to similar methods employed in the industry. Thirdly, a complex analytical model named Two Parameter Approach (TPA) is developed, defining the usage profile of a vehicle in terms of a bivariate probability density distribution of two parameters (distance/day, fatigue damage/distance), derived from measurements and surveys. Based on an inversion of the TPA model, a robust technique is developed for the derivation of such statistical usage profiles from only field failure data. Lastly, the applicability of the methods is demonstrated on a wide range of comprehensive case studies. Importantly, in most cases, substantiation of the methods is achieved by comparison of predicted failures with ‘real-world’ failures, in some cases made possible by the unusually long duration of the study. / Thesis (PhD (Mechanical Engineering))--University of Pretoria, 2007. / Mechanical and Aeronautical Engineering / PhD / Unrestricted

Denna studie genomfördes för att undersöka hur Volvo Trucks som globalt företag i Nordamerika riktar sin kommunikation gentemot mottagare i kampanjfilmer. Varav vi har tittat på två som är skapade med att främst rikta sig till den nordamerikanska publiken och den tredje till den globala. Vi gjorde detta för att undersöka vilka visuella arrangemang man använder sig av för att väcka uppmärksamhet och förtroende på en relativt ny marknad som Nordamerika är. För att göra detta har vi genomfört en kvalitativ intervju med en anställd på kommunikationsavdelningen i Nordamerika. För titta närmare på kampanjfilmerna har vi genomfört en multimodal analys för att undersöka vad vi ser i respektive scen. Våra resultat har visat att Volvo Trucks Nordamerika använder sig av symboler, karaktärer och miljöer i sina kampanjfilmer för att de nordamerikanska mottagarna ska uppleva igenkänning och gemenskap för att få förtroende för företaget. I kampanjfilmen som främst riktar sig till den globala publiken, använder sig däremot Volvo av andra känslor samt igenkänningsfaktorn som spänning och internationella karaktärer för att mottagarna ska uppmärksamma Volvo Trucks som varumärke. / This study was designed to investigate Volvo Trucks in North America's focus in how the company communicates to their target group in their campaigns. We also investigated which visual imagery they use to attract attention and retrieve trust on a relatively new market such as North America. A qualitative interview was performed with an employee at the communication center in North America. A more deeper analysis of the campaigns was made with a multi-modal analysis, which helped us investigate what we see in each scene in the campaigns. The result showed that Volvo Trucks in North America uses symbols, characters and environments in their campaigns in a way that makes north Americans recognition and therefore the company receives trust. While the campaign that is directed to the global public uses other emotions and recognitions like excitement and international character, so more people can feel attachment with the Volvo Truck brand.

Pour répondre à la fois aux nouvelles normes législatives et aux exigences du client, la complexité des camions s’est vue fortement augmentée au cours de ces dernières décennies. En plus de réduire les émissions de polluants, ces nouvelles normes imposent la mise en place d’un système de diagnostic des systèmes anti-pollution. Cela implique donc un contrôle plus fin ainsi qu’une surveillance accrue de ces dits systèmes. Le client quant à lui désire augmenter sa productivité et donc la disponibilité des camions. Afin de remplir ces exigences, le développement d’observateurs (ou capteur logiciel) représente une solution attractive. Ils permettent en effet d’obtenir plus d’informations à partir d’un nombre de capteurs donné, sans coûts supplémentaires pour le constructeur. Au cours de cette thèse, plusieurs observateurs ont été développés pour différents sous-systèmes du camion, dont des observateurs non-linéaires, LPV (Linéaire à Paramètres Variants), et avec retard. Dans un premier temps, dans le cadre de la surveillance et de la maintenance préventive, des observateurs ont été conçus dans le but d’estimer différents coefficients caractéristiques de la dégradation d’équipements tels que : un tendeur de courroie, le refroidisseur d'air de suralimentation et le refroidisseur des gaz d'échappement recirculés (EGR). Un observateur de la pression du collecteur d’échappement a également été développé dans le but de diagnostiquer un défaut du capteur mesurant cette pression. Dans un second temps, l’estimation du débit d’air massique EGR a été utilisée pour tester différentes méthodes d'observation sur banc d’essai, cette variable étant importante dans le contrôle des émissions de polluants. Enfin, dans une optique de réduction de coût, une estimation des débits d’air massiques entrant dans le moteur et celui de l’EGR a été réalisée sur la base d’un capteur soumis à un retard. / To meet both new legislative standards and customer requirements, the complexity of trucks has increased significantly in the recent decades. In addition to reducing pollutant emissions, these new standards require on board diagnosis solutions for anti-pollution systems. Therefore it implies a thiner control and increased monitoring of these systems. Besides, the customer wants to increase productivity and therefore the availability of the truck. In order to fulfil these requirements, the development of observers (or virtual sensors) is an attractive solution. Indeed, more information can be obtained from a given number of sensors, without additional cost for the manufacturer. During this thesis, several observers were developed for different truck subsystems, including non-linear, LPV (Variable Parameter Linear) or delay observers. As a first step, from a monitoring and preventive maintenance point of view, observers have been designed to estimate different equipment degradation ratio such as: a belt tensioner, a charge air cooler and an exhaust gas recirculation (EGR) cooler. An observer of the exhaust manifold pressure has also been developed to diagnose a fault of the sensor measuring this pressure. In a second step, the EGR mass flow rate estimation was used to test different observation approaches on a test bench, this variable being important for the pollutant emissions control. Finally, in order to reduce cost, the observation of the inlet air and EGR mass flow rates has been studied with a sensor submitted to a delay.

The goal of this thesis is to determine the contributing factors affecting severe traffic crashes (severe: incapacitating and fatal - non-severe: no injury, possible injury, and non-incapacitating), and in particular those factors influencing crashes involving large vehicles (heavy trucks, truck tractors, RVs, and buses). Florida Department of Highway Safety and Motor Vehicles (DHSMV) crash reports of 2008 have been used. The data included 352 fatalities and 9,838 injuries due to large vehicle crashes. Using the crashes involving large vehicles, a model comparison between binary logit model and a Chi-squared Automatic Interaction Detection (CHAID) decision tree model is provided. There were 13 significant factors (i.e. crash type with respect to vehicle types, residency of driver, DUI, rural-urban, etc.) found significant in the logistic procedure while 7 factors found (i.e. posted speed limit, intersection, etc.) in the CHAID model. The model comparison results indicate that the logit analysis procedure is better in terms of prediction power. The following analysis is a modeling structure involving three binary logit models. The first model was conducted to estimate the crash severity of crashes that involved only personal vehicles (PV). Second model uses the crashes that involved large vehicles (LV) and passenger vehicles (PV). The final model estimated the severity level of crashes involving only large vehicles (LV). Significant differences with respect to various risk factors including driver, iii vehicle, environmental, road geometry and traffic characteristics were found to exist between those crash types and models. For example, driving under the influence of Alcohol (DUI) has positive effect on the severity of PV vs. PV and LV vs. PV while it has no effect on LV vs. LV. As a result, 4 of the variables found to be significant were similar in all three models (although often with quite different impact) and there were 11 variables that significantly influenced crash injury severity in PV vs. PV crashes, and 9 variables that significantly influenced crash injury severity in LV vs. PV crashes. Based on the significant variables, maximum posted speed, number of vehicles involved, and intersections are among the factors that have major impact on injury severity. These results could be used to identify potential countermeasures to reduce crash severity in general, and for LVs in particular. For example, restricting the speed limits and enforcing it for large vehicles could be a suggested countermeasure based on this study.

Recent advancements in social networking and technology, and the increasing popularity of “gourmet” food trucks, have brought renewed attention to mobile food vending. Research indicates that vendors can provide inexpensive food to city dwellers and have a positive impact on the vibrancy of public spaces. The recent popularity of vendors, however, has fueled ongoing debates over public space use and regulation. Municipalities are looking to craft policies to appease community members with a range of opinions on the acceptability of vending on public streets. This thesis uses the case study of Los Angeles to attempt to answer the research question: What are the relationships among policies on food vendors, food vendors, and the public’s use and perception of urban space? The study triangulates information gathered from public space user surveys, behavior mapping and observation, in-depth interviews, and archival research to address this research question. Findings indicate that vending can contribute to vibrancy and activity in public spaces, and public space users generally perceive vendors positively. Findings of the research also suggest, however, that some public spaces do not provide adequate amenities for food truck customers and public space users. These, and other findings, are used to inform the policy and planning recommendations presented in this study.

Air quality permits are required for the construction of all new surface mining operations. An air quality permit requires a surface mining operation to estimate the type and amount of pollutants the facility will produce. During surface mining the most common pollutant is particulate matter having an aerodynamic diameter less than 10 microns (PM10). The Industrial Source Complex (ISC3) model, created by the United States Environmental Protection Agency (U.S. EPA), is a model used for predicting dispersion of pollutants from industrial facilities, including surface mines and quarries. The use of this model is required when applying for a surface mining permit. However, the U.S. EPA and mining companies have repeatedly demonstrated that this model over-predicts the amount of PM10 dispersed by surface mining facilities, resulting in denied air quality permits. Past research has shown that haul trucks create the majority (80-90%) of PM10 emissions from surface mining operations. Therefore, this research concentrated on improving the ISC3 model by focusing on modeling PM10 emissions from mobile sources, specifically haul trucks at surface mining operations. Research into the ISC3 model showed that its original intended use was for facilities that emit pollutants via smoke stacks. The method used to improve the ISC3 model consisted of applying the dispersion equation used by the ISC3 model in a manner more representative of a moving haul truck. A new model called the Dynamic Component Program was developed to allow modeling of dust dispersion from haul trucks. To validate the Dynamic Component Program, field experiments were designed and conducted. These experiments measured PM10 from haul trucks at two different surface mining operations. The resulting analysis of the Dynamic Component Program, ISC3 model, and the actual field study results showed that the Dynamic Component Program was a 77% improvement over the ISC3 model overall. / Ph. D.

A human factors experiment was conducted to assess the intelligibility of synthesized speech under a variety of noise conditions for both hearing-impaired and normal-hearing subjects. Modified Rhyme Test stimuli were used to determine intelligibility in four speech-to-noise (S/N) ratios (0, 5, 10, and 15 dB), and three noise types, consisting of flat-by-octaves (pink) noise, interior noise of a currently produced heavy truck, and truck cab noise with added background speech. A quiet condition was also investigated. During recording of the truck noise for the experiment, in-cab noise measurements were obtained. According to OSHA standards, these data indicated that drivers of the sampled trucks have a minimal risk for noise-induced hearing loss due to in-cab noise exposure when driving at freeway speeds because noise levels were below 80 dBA. In the intelligibility experiment, subjects with hearing loss had significantly lower intelligibility than normal-hearing subjects, both in quiet and in noise, but no interaction with noise type or S/N ratio was found. Intelligibility was significantly lower for the noise with background speech than the other noises, but the truck noise produced intelligibility equal to the pink noise. An analytical prediction of intelligibility using Articulation Index calculations exhibited a high positive correlation with the empirically obtained intelligibility data for both groups of subjects. / Master of Science

The design of the freight train truck has gone relatively unchanged over the past 150 years. There has been relatively little change to the fundamental railway truck design because of the challenges of implementing a cost effective and reliable modification to designs that have proven effective in decades of operation. A common U. S. railway truck consists of two sideframes, a bolster, two spring nests, and four friction wedges. The two sideframes sit on the axels. The bolster rides on springs on top of the sideframes. The friction wedges also ride on springs on top of the sideframe, and are positioned between the bolster and sideframe, acting as a damping mechanism. Better understanding the dynamic behavior and forces on the bodies are critical in reducing unnecessary wear on the components, along with potential negative behavior such as loss of productivity and increase in operating costs. This thesis will investigate the dynamic behavior of the truck under warping conditions using a stand-alone model created in Virtual.Lab. This research covers two main areas. First, the full-truck model will be developed and its simulation results will be compared to test data from the Transportation Technology Center, Inc. (TTCI). Data was provided from warp testing performed at the TTCI facilities in the spring of 2008. Once validated, the model will be used to gain a better understanding of the forces and moments that are propagated through the system, and of the dynamics of all bodies. Due to costs and physical constraints, not every bogie component can be instrumented during test, so the computer model will be able to provide valuable information not easily obtained otherwise. Second, full-truck models using different contact geometry between the wedges, sideframes, and bolster will be compared. A model with extremely worn sideframes will allow for investigation into the effects of wear on the damping abilities and warp stiffness of the truck. Another model using split wedges will be compared with the previous model to investigate into the behavior differences in the truck using different types of wedges. By understanding the impact of different geometries on the overall performance of the truck, better decisions on design and maintenance can be made in the future. After creating the models, we found that the full-truck model created in LMS® Virtual.Lab compared well with the test data collected by TTCI. In the comparison with NUCARS® we determined that the stand-alone model, which incorporates the wedges as bodies, captures the warp dynamics of the truck better than NUCARS®, which models the wedges as connections. By creating a model with severely worn sideframes, we were able to determine that the truck loses its abilities to damp bounce in the system as well as to prevent warping when the components become sufficiently worn. The split-wedge model behaved similarly to the standard full-truck model for bounce inputs, but had a significantly different behavior in warp. Further development will be needed on the split-wedge model to be confident that it behaved as expected. / Master of Science

This thesis had the goal to investigate the potential of 90+ ton trucks in Sweden. As of current, the highest allowed weight on public roads is 74 ton. A few research questions were formulatedin order to capture the most important aspects of the system in which these vehicles operate. The research questions were what the potential economic savings could be, what the environmental improvements could be, where these vehicles best operate and which barriersthat exist for these vehicles to be successfully deployed. The method has consisted of a literature study, interviews with experts and building asimulation model to see if the efficiency observed in some cases would be applicable to other cases as well. The results from the simulations show the same positive trend toward bigger trucks even withmore and longer routes driven. This was the case even when prices for fuel were set to different values in order to see its effect on the relation between the compared trucks. It was also shown that the heaviest vehicle, 98 tons, still would be more effective if its cargo weight was reduced by 10%. The conclusions from the study is that the BK4 road network that exists in Sweden need to be expanded as well as bridges in the network being analyzed and reinforced to handle proposed gross weights in the future. For the 90+ ton trucks themselves, rigid flows of biomass like int hose cases where terminal driving occurs are the most suitable cases for the trucks due to the predictability of the high biomass flow.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2005. / Vehicle Noise, Vibration and Harshness (NVH) is now a more important component of the vehicle design process than ever. Road noise is one of the key criteria used by potential buyers (albeit subconsciously) to choose what they perceive as the best vehicle. Road rumble is a key concern for vehicle manufacturers. Light Utility Vehicles (LUVs) are especially sensitive to a low frequency booming noise due to the fundamental acoustic mode that exists in the vehicle cabin. An investigation into this booming noise in an LUV is documented. The noise is identified and quantified after which the source of the noise in the vehicle cabin is identified using NVH techniques such as Acoustic Modal Analysis (AMA), Experimental Modal Analysis (EMA) and Transfer Path Analysis (TPA). The cabin’s fundamental acoustic mode lay at 100 Hz. Finally the source of the vibrations in the vehicle leading to the booming noise in the cabin is identified, along with its transfer path to the cabin. Solutions for the specific vehicle’s booming noise are proposed, two of which are tested with some success. Solutions to the problems associated with the fundamental acoustic mode of LUVs are also proposed and discussed.