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Introduction: The occurrence of mixed fracture mechanisms in mechanical elements is frequent, due to the action of multiple factors that intervene during their design, manufacturing and operation. Objective: To establish the causes of failures in tripod columns on trucks, based on the characterization of the base metal and the welded joints in the failure region. Materials and Methods: Visual inspection of the failures, chemical and microstructural characterization by optical microscopy of the columns, as well as tensible test of the base material were carried out. Results and Discussion: The integrated visual inspection analysis and the results of chemical and metallographic characterization reveal that the material of the columns is not recommended for welded structures and that measures such as preheating and thermal treatment after welding were not taken. Due to the characteristics of the steel and the location of the detected cracks, they may be associated with diffusible hydrogen cracking. Conclusions: The failure of the columns was the result of a combination of several factors, highlighting design and manufacturing errors in the selection of a non-recommended material and the non-execution of attenuation measures during the execution of the welding, also linked to factors such as, possible overloads or improper operation of the equipment. [ABSTRACT FROM AUTHOR]

We introduce a method for the selection and processing of a biological model to derive an outline that provides morphometric information for a novel aerodynamic truck design. Because of the dynamic similarities, our new truck design will be inspired by biological shapes with a known high level of streamlining and low drag for operation near the seabed, i.e., the head of a trout, but other model organisms will also be used later. Demersal fish are chosen because they live near the bottom of rivers or the sea. Complementary to many biomimetic studies so far, we plan to concentrate on reshaping the outline of the fish's head and extend it to a 3D design for the tractor that, at the same time, fits within EU regulations and maintains the truck's normal use and stability. We intend to explore this biological model selection and formulization involving the following elements: (i) the reason for selecting fish as a biological model for a streamlined truck design; (ii) The choice of a fish model via a functional similarity method; (iii) biological shape formulization based on the morphometric information of models in (ii) outline pick-up, a reshaping step and a subsequent design process; (iv) modify the biomimetic designs and test utilizing CFD; (v) further discussion, outputs and results from the bio-inspired design process. [ABSTRACT FROM AUTHOR]

To support worker and driver safety, this study conducted a comprehensive literature review to identify methods of enhancing TMA visibility, improving work zone configurations, and ensuring worker safety. To increase TMA recognition, this study observed that the use of a 6-to-8-inch wide yellow and black inverted 'V' pattern of retroreflective chevron markings, sloped at a 45-degree angle downward in both directions from the upper center of a rear panel is effective in alerting drivers to work zones. This study also recommends applying amber and white warning LEDs, which flash in an asynchronous pattern at a 1 Hz frequency and are mounted against a solid-colored background for a 360-degree view visible at least 1500 feet from the work zone. In addition, a work zone vehicle configuration consisting of a lead, buffer, and advance warning truck with a buffer space between 100 and 150 ft is suggested to reduce the risk of lateral intrusions and TMA roll-ahead. In parallel, workers should wear high-visibility vests noticeable at a minimum distance of 1000 feet and headwear with at least 10 square inches of retroreflective material. Some intelligent transport systems are also suggested to enhance TMA recognition and potentially minimize work zone fatalities. Application of the recommended guidelines will potentially improve current practices and significantly reduce the occurrence of TMA crashes in construction and maintenance work zones. [ABSTRACT FROM AUTHOR]

In this study, we developed a system to collect and analyze log data related to truck travel times in underground mines using Bluetooth beacons and tablet computers. When a signal from beacons installed at a major underground mine is received by a truck-mounted tablet computer, the beacon information is collected and uploaded to a cloud server. A data processing program integrates the uploaded log data files into a single file, calculating the statistical values for each section of the transport route. The developed system was applied to a limestone underground mine located in Jeongseon, Korea, to diagnose and analyze the transport routes in the study area. As a result of this analysis, it was possible to select sections in which the truck transport time was stable and sections in which it was unstable. Consequently, the transport route could be classified into four types based on the distribution and fluctuations in the truck transport time data. Moreover, it was possible to analyze the causes of the stable and unstable sections through production logs and field staff interviews. The developed system could be used as a tool to improve transport operations by diagnosing and analyzing the truck transport routes of a mine. [ABSTRACT FROM AUTHOR]

The cost of storing and transporting hydrogen have been one of the main challenges for the realization of the hydrogen economy. Liquid organic hydrogen carriers (LOHC) are a promising novel solution to tackle these challenges. In this paper we compare the LOHC concept to compressed gas truck delivery and on-site production of hydrogen via water electrolysis. As a case study we consider transportation of by-product hydrogen from chlor-alkali and chlorate plants to a single industrial customer, which was considered to have the greatest potential for the LOHC technology to enter the markets. The results show that the LOHC delivery chain could significantly improve the economics of long distance road transport. For economic feasibility, the most critical parameters identified are the heat supply method for releasing hydrogen at the end-user site and the investment costs for LOHC reactors. Image 1 • Techno-economic model for point-to-point large scale road transport of hydrogen. • The LOHC concept can decrease long-distance delivery costs significantly. • Heat supply method for dehydrogenation and heat integration are key. • Utilization of waste heat can reduce costs by 40%. [ABSTRACT FROM AUTHOR]

SolidWorks and ANSYS Workbench were used to establish solid model and perform FEM analysis of truck with and without sealing covers respectively. In the past practical production, there has been no precedent for the modal analysis of the truck carriage with a sealing cover; the modal analysis is carried out for the first time in this paper. The vibration characteristics of the truck carriage are obtained. The first ten-order of non-rigid mode of the newly development truck carriage is obtained and the excitation frequency range of the idling state of the engine is calculated to avoid resonating with the ground. In order to avoid the resonance phenomenon during the truck running, the vibration characteristics of the new carriage model were studied, the first ten non-rigid modes of the new carriage model were extracted, and the excitation frequency range of the engine during idling was calculated. The non-rigid natural frequencies of the first 10 free models are between 6.18 ∼ 26.74 Hz. The engine idling excitation frequency is 32.5 ∼ 145 Hz, and the common excitation frequency caused by road roughness is 3 Hz. In theory, it does not cause resonance when driving in a normal state. [ABSTRACT FROM AUTHOR]

One major issue that is source of uncertainty holding back the hydrogen deployment, is the infrastructure development needs and costs. Different studies in the literature tackled this issue in France but partially, assessing either one part of the hydrogen supply chain or the whole supply chain but for one possible delivery pathway. This paper compares five hydrogen pathways, going from the production step up to the fuelling station and tackling pipeline and truck options. In order to capture the time evolution aspect of the infrastructure deployment needs, three demand scenarios are investigated, going from 1% of market penetration up to 15%. Additionally, two scenarios are taken into account when it comes to the location of the hydrogen production sites vis-à-vis the demand centres. According to the results, economies of scale that can be driven by higher market penetration rates have significant impact on lowering the hydrogen cost. • Infrastructure costs are source of uncertainty hampering the hydrogen deployment. • Five hydrogen delivery pathways, going up to the refuelling stations, are compared. • Three scenarios are investigated for the hydrogen demand in passenger mobility. • GIS modelling allowed to visualize a potential infrastructure deployment. • The economies of scale have significant impact on lowering the hydrogen cost. [ABSTRACT FROM AUTHOR]

Copyright of Inzynieria Mineralna is the property of Polskie Towarzystwo Przerobki Kopalin and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new method using a deep neural network (DNN) model is proposed to predict the ore production and crusher utilization of a truck haulage system in an underground mine. An underground limestone mine was selected as the study area, and the DNN model input/output nodes were designed to reflect the truck haulage system characteristics. Big data collected on-site for 1 month were processed to create learning datasets. To select the optimal DNN learning model, the numbers of hidden layers and hidden layer nodes were set to various values for analyzing the training and test data. The optimal DNN model structure for ore production prediction was set to five hidden layers and 40 hidden layer nodes. The test data exhibited a coefficient of determination of 0.99 and mean absolute percentage error (MAPE) of 2.80%. The optimal configuration for the crusher utilization prediction was set to four hidden layers and 40 hidden layer nodes, and the test data exhibited a coefficient of determination of 0.99 and MAPE of 2.49%. The trained DNN model was used to predict the ore production and crusher utilization, which were similar to the actual observed values. [ABSTRACT FROM AUTHOR]

The potential performance of two different ways of designing truck assembly systems, namely line and dock assembly, are analysed. The line system denotes assembly at a mechanically paced moving belt with fixed items, divided in several one-worker stations with a common station time around 20 minutes and located in parallel with up to three other station. The dock system denotes assembly at stations with typical station times around 4 hours the items are moved between station by the workers, who are divided in groups of around ten persons assembling complete trucks. Theoretical models for these specific system are presented which together with the results are applicable to more general situations. The net and gross and times and derived for line and clock assembly where net work time denotes time when work is done and gross work time is net plus lost work time. The potential efficiencies are expressed as the quotient between the net and gross time. The models and hypotheses of human behaviour. A difference between the gross work times of around 30% is obtained in favour of dock assembly, when data from the literature and an existing line are used. Experiments support this result. A maximum work speed consistent personal comfort and safely for each individual and rational cooperation between the group members are assumed. [ABSTRACT FROM AUTHOR]

The article discusses the feasibility of using linear programming for production planning by a medium-sized truck body manufacturer. Linear programming was chosen due to the realism of the necessary assumptions. A linear programming model was adapted for scheduling production and work force levels for one particular type of truck body produced by the firm on a production run basis. A Mathematical Programming Systems (MPS) package was used to obtain the solution of this linear programming problem. The output of the program was a schedule of the monthly employment and production rates for a six-month period of time. A new production forecast was prepared at the end of the first month and the program was rerun with updated information to provide a schedule for the following six months.

Vision-based monitoring methods have been actively studied in the construction industry because they can be used to automatically generate information related to progress, productivity, and safety. Object detection is essentially used in such monitoring methods to infer jobsite context. However, as many classes of construction entities exist in a job site, large amounts of image data are required to train a detection algorithm to detect each class object in images. Although image data augmentation methods using 3D models were proposed, publicly available 3D models are limited to some construction object classes. Therefore, this study proposes a three-dimensional reconstruction method to generate the image data required for training object detectors. To use the generated synthetic images as training data, a histogram of oriented gradient (HOG) descriptor of a target object is obtained from these images. The descriptor is refined by a support vector machine to increase sensitivity to the target object in test images. The performance of the HOG-based object detector is evaluated using real images from ImageNet. The result shows that the proposed method can generate training data more effectively than existing manual data collection practices. [ABSTRACT FROM AUTHOR]

Although the Australian road freight transport industry has seen three mass limits reviews in the mid 1970s, the mid 1980s and in the late 1990s, (Hassall, 2005), there were two very significant truck configuration changes that happened in the mid 1980s and then again in the early 2000s. The first was the trials of a variant of the Canadian B-train (the B-Double) which was introduced into Australia in the mid 1980s. This 'Australian' B-Double could achieve payloads some 30% to 40% higher than the conventional 'semi trailer' articulated combination. By 2016 some 18,900 of these vehicles were operational in Australia. The second adoption of new vehicle configurations started in 1999 through the National Road Transport Commission (NRTC), who adopted, and further developed, another Canadian concept, that of "Performance Based Standards" (PBS). This effectively allowed for new, flexible truck designs, as long as the vehicles performed against a set of 17 specific technical engineering performance criteria. This Performance Based Standards approach, since 1998, also allowed even larger configurations to B-Doubles to be used by operators. The benefits of these new configurations have already delivered billions of dollars in kilometre savings to the road freight industry and to its customers, as well as very significant safety benefits to the community. [ABSTRACT FROM AUTHOR]

Natural gas fuel, as an alternative energy source of transportation, has been used widely since it has an advantage of low emission levels. However, new technologies are required in order to meet the reinforced emission regulations. For this purpose, research into the development of hydrogen-compressed natural gas (HCNG) blend engine was carried out to evaluate its feasibility and emission characteristics. The Engine Research Department at the Korea Institute of Machinery and Materials carried out a large number of tests based on various parameter changes that could affect the performance and emission of HCNG engine in different operating conditions. An earlier stage of the research project focused on the lean combustion of a HCNG engine for heavy duty vehicles to meet the EURO-VI standards. An 11-L/6-cylinder CNG engine was used for the test. The effects of the excess air ratio change were assessed based on various content ratios of hydrogen in the natural gas fuel. In the later part of the HCNG research, a stoichiometric mixture operation was suggested to meet reinforced emission regulation without requiring a De-NOx system. Additionally, an exhaust gas recirculation (EGR) system was introduced for the purpose of improving thermal efficiency and durability. The optimal operating conditions were selected to achieve the best thermal efficiency to meet the required emission levels. In this paper, we demonstrate that a HCNG engine can achieve a significant decrease in NOx emissions, as compared to that of a CNG engine, while meeting the requirements of the EURO-VI standards during a transient mode cycle test. EGR can suppress the weakness of stoichiometric mixture combustion strategy, such as the deterioration of the durability and thermal efficiency, while the emission level can be lowered with the use of a three-way catalyst. The possibility of further reduction of emissions and CO2 with EGR was evaluated to access practical application of a HCNG engine in the field. From that evaluation, the HCNG engine with stoichiometric mixture operation for heavy duty vehicles was developed. The emission levels of HCNG engine were 50 % lower when compared to the EURO-VI standards with a greater than 10 % decrease in CO compared to that of a natural gas engine. [ABSTRACT FROM AUTHOR]

Hand trucks are frequently used in delivery and moving occupations to move a variety of materials including appliances and beverages. Frequently these transport tasks involve ascending or descending stairs. This research assessed the efficacy of three commercially available alternative hand truck designs that could be used to deliver appliances. Nine experienced participants moved a 52.3 kg washing machine up and down a flight of stairs using a conventional two-wheeled hand truck, a multi-wheeled hand truck, and a two-speed powered hand truck. Electromyographic (EMG) data showed reduced right erector spinae, bilateral trapezius, and bilateral biceps 90th and 50th percentile normalized responses while ascending and descending the stairs when using the powered hand truck. The multi-wheel hand truck did not reduce EMG levels relative to the conventional hand truck. Participants, however, did express a potential concern regarding the ascent time with powered hand truck at the slower speed. • Short haul delivery drivers often need to transport heavy freight up or down stairs on hand trucks. • This study compared the muscular effort when using alternative hand truck designs, including a 2 speed powered hand truck. • The powered hand truck reduced electromyographic activity in some arm and trunk muscles during stair ascent and descent. [ABSTRACT FROM AUTHOR]

The aim of this paper is to analyse the mechanical properties of the weld steel structure of car body truck frames after laser welding. The best welding conditions involve the use of proper materials and alloy elements in steel and filer materials, in addition to welding technology, state of stress and temperature of exploitation. We present for the first time the properties of steel track structures after laser welding with micro-jet cooling. Therefore, good selection of both welding parameters and micro-jet cooling parameters is very important to achieve a proper steel structure. In this study, the metallographic structure, tensile results and impact toughness of welded joints have been analysed in terms of welding parameters. [ABSTRACT FROM AUTHOR]

In this study, an autonomous mobile inspection system that can detect and quantify hidden voids in a secondary barrier (triplex layer) of a liquefied natural gas cargo tank is developed using lock-in thermography. The triplex layer is the secondary barrier to prevent gas leaks from a Mark III–type membrane liquefied natural gas carrier cargo tank and consists of three sub-layers: a flexible secondary barrier, a bonding layer, and a rigid secondary barrier. The proposed mobile inspection system consists of a lock-in thermography measurement unit, a mobile inspection unit, and image processing algorithms. First, thermal images are obtained using the lock-in thermography unit as the mobile inspection system maneuvers over triplex layers. Second, the raw thermal images are processed by several image processing techniques to compensate for non-uniform heating, eliminate noise components, and disregard trivial voids in accordance with the current inspection guideline. Third, the void size is more precisely quantified using an empirical mapping function that relates the void size estimated in the previous step to that measured by an independent X-ray test. The contributions of this study include the following: (1) an autonomous mobile inspection system is developed for real-time inspection of the triplex during its installation, significantly saving the inspection cost and time; (2) a suite of image processing techniques is developed, overcoming shortcomings of the existing thermography non-destructive testing techniques; and (3) the sizes as well as the locations of the hidden voids are quantified with high accuracy, reliability, and fast inspection speed. [ABSTRACT FROM AUTHOR]

A rear under-ride protection device is a metal structure that is found on the rear side of the trucks usually made of steel. At present some of the countries claimed to have developed ‘under-ride protection device’ to address the problems related to automobile crashes especially car colliding with a truck from its rear side. However, the crashes lead to fatal ends due to the poor performance of the under-ride protection devices. This review is aimed to discuss the crashworthiness of vehicles under collisions, specific energy absorption during accidental impacts, energy absorbing systems, various types of materials used for energy absorption, under-ride protection devices and various types of under-ride protection devices that exist in the current market. [ABSTRACT FROM PUBLISHER]

To comply with the new non-road emission standards, final Tier 4, two big strategies have been applied to the 11 L heavy-duty diesel engine. The first strategy is to apply Exhaust gas recirculation and selectivity catalytic reduction system to meet the NOx limitation. The other one is to apply low swirl ratio (for higher volumetric efficiency) and multi-hole nozzle, a high pressure direct injection, and an optimized combustion system in order to reduce PM emission. Both strategies put a focus on the optimization of combustion system. In this study, a ULPC bowl concept applied in the previous works has been successfully verified in 11 L heavy-duty diesel engine with wellvalidated 3D combustion simulation, and the ULPC bowl shape has been geometrically optimized. A rough 0D calculation is used to calculate the fuel split ratio of the various ULPC bowl shapes. In the rated-power operating condition of the final Tier 4 engine which is deduced by 1D cyclic simulation, the optimal fuel split ratio of the injected fuel has been verified. Also, additional geometric optimization has been achieved without changing the optimal fuel split ratio. From these results, soot has been reduced by about 30% with ULPC optimum bowl shape against the Tier 3 re-entrant bowl shape. [ABSTRACT FROM AUTHOR]

The article presents the methods for experimental and theoretical research of vibration loads and dynamic stresses of automobile frame. The comparative analysis of the finite element stress and acceleration is performed with SolidWorks and Ansys software with the use of resistive strain gages and g-meters data obtained during automobile road tests. Frame fatigue life calculation of using multibody dynamics model in FRUND software is given. Load-carrying structures of automobiles undergo external loads which are time- and frequency-variable, depending on velocity, current weight, road profile and other factors. Such loading mode provokes the occurrence of fatigue cracks, and their promotion can entail fracture. Thus, frames and load-carrying structures are subjects of cyclic loading tests purposed to estimate stress level and reliability of the structures and detect possible failures. The motion was considered for following road types: concrete road, smooth cobblestone road and special cobblestone profile. Road types and automobile velocities are corresponding to input data for dynamic simulation in FRUND multibody dynamics system. [ABSTRACT FROM AUTHOR]

In this paper, the full-float cab suspension of a self-dumping truck was taken as research object, and a multi-body dynamics model of the self-dumping truck was built based on virtual prototype technology. Then a road test of ride comfort of the vehicle was implemented to verify the validity of the dynamic model. On this basis, the spring stiffness and damping of cab suspension were optimized for improving ride comfort based on grey relational analysis. Meanwhile, a comparison between GRA and TOPSIS was conducted to illustrate the unique merits of grey relational analysis in multi-objective optimization. Then the optimal combination of cab suspension parameters was verified by ride comfort test. The analysis results indicated that the improvement of ride comfort of self-dumping trucks can be up to 15.69% by using the optimal parameters. Hence, the grey relational analysis was a very powerful method used for optimizing the cab suspension parameters. [ABSTRACT FROM AUTHOR]

The present paper presents the design and optimization procedure for parabolic leaf springs for truck axle payloads of 7.5 and 8.0 tons. The requirements to be met in such a process cover the kinematic behavior of the spring (the conformation of the trajectory of the wheel joint connected to the spring with the trajectory of the steering arm), the spring rates, as well as strength and, most importantly, durability criteria. Therefore, a multi-disciplinary optimization has been performed aiming at the fine tuning between the vehicle’s wheel joint kinematics, the leaf stress response and damage for certain multiaxial load spectra. Optimized kinematics have been calculated using proper design parameters. The springs’ durability has been theoretically assessed based on (a) FEM-calculated stresses at pure vertical loading and braking events, which have been identified to cause the highest stresses in operation, and (b) analytical damage calculations for certain multiaxial load sequences based on the Miner’s elementary linear damage accumulation rule. The vehicle’s kinematics behavior has been verified experimentally by driving prototypes at test tracks. Straight-driving, cornering, comfort and steering behavior have been quantitatively evaluated by 7 different expert drivers. The developed springs were found to perform equivalently to (in case of the 8.0 ton spring) or significantly better (in case of the 7.5 ton spring) than the respective serial springs. [ABSTRACT FROM AUTHOR]

Tire failure in mining operations can be hazardous, resulting in financial and productivity losses. There are opportunities to improve tire monitoring systems by safely and remotely providing full-field measurements of tire properties. An optical fault detection system has been developed to investigate the feasibility of using digital image correlation to measure displacement and strain on a tire surface with the aim of detecting tire damage. This study defines metrics for damage visibility and examines the visibility of different damage types at multiple orientations in a laboratory setting. Internal and external damage was successfully detected from changes in surface strain. Knowledge gained from this investigation can be used to drive the future development of industrial tire monitoring solutions. [ABSTRACT FROM AUTHOR]

Finite-element simulations were used to investigate the structural demands generated by a truck colliding with a bridge pier. A reduced coupled mass-spring-damper model is proposed to simulate the collision process. The model is calibrated to the simulation data and accounts for key variables, such as truck weight, impact speed, and pier characteristics. Through comparisons to detailed finite-element analysis, the reduced model is shown to be able to reasonably represent the behavior of a set of coupled vehicle-bridge systems. On the basis of the simulation results, an argument is made that a standard design truck can be specified for impact design. [ABSTRACT FROM AUTHOR]

Front axle is one of the important parts of vehicle. The Fatigue Tool in ANSYS Workbench software is used to analyze its strength situations and fatigue life. The dangerous area of beam is determined, which provides a certain basis for structure improvement. In addition, in view of three kinds of working condition often used, a combined fatigue simulation of multiworking conditions is carried out. The influence of different conditions on fatigue life is studied. Finally, fatigue life of front axle containing crack is investigated to analyze the effect of crack parameters such as length and depth on fatigue life. [ABSTRACT FROM AUTHOR]

Grounded improvement process transporting grain from combines and semitrailers tippers specified on rational method of determining the parameters for the application in the field of movable carts. Obosnovano usovershenstvovanye tehnolohycheskoho process of transportation of grain from combine Tipper semi refined and sootvetstvuyuschaya method for determining parameters at ratsyonalnыh Application for work in the field podkatnыh vozkov. It is proved developments of technological process of conveyance of grain from combines by semi-trailers dump trucks and the matching technique of determination of rational parametres is specified at application for work in the field of roll sleigh. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Papers of Silesian University of Technology. Organization & Management / Zeszyty Naukowe Politechniki Slaskiej. Seria Organizacji i Zarzadzanie is the property of Silesian Technical University, Organisation & Management Faculty and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Active Flow Control (AFC) is being investigated as a tool for boundary layer separation delay. Increasing lift by delaying stall has been the most common objective. More recently AFC is also being studied for drag reduction and mitigation of unsteadiness, resulting from massively separated flows. As such, fuel savings of heavy ground vehicles, while challenging, is a worthy task due to the huge economic, environmental and political impact. This paper describes a series of experiments aimed at increasing the base pressure on the trailer-end of a large truck–trailer configuration driving at highway speeds. In parallel to fundamental studies, not reviewed here for brevity, two road test campaigns were completed; a half scale wind tunnel test and smaller scale generic vehicle model wind tunnel experiments are described and analyzed. The method currently uses a 1/4 cylinder shaped rear-end mounted add-on device in which an array of synchronized Suction and Oscillatory blowing (SaOB) actuators is mounted. The passive as well as active effects of the steady suction and unsteady sideways-oscillating blowing are documented and careful experimentation allows the energy budget to be directly calculated from wind tunnel experiments. Good agreement between road tests and scaled tunnel model tests was found on the path to product development. [ABSTRACT FROM AUTHOR]

The paper provides a discussion on various solutions used in suspension systems of special-purpose vehicles. On account of its low cost and design simplicity owing to which it is commonly applied, the mechanical dependent suspension system based on leaf springs has been described. The paper also addresses non-conventional pneumatic and hydropneumatic systems based on gas springs, allowing for selected suspension parameters to be controlled, including clearance. [ABSTRACT FROM AUTHOR]

Structural optimization for vehicle fatigue durability signifies an exciting topic of research to improve its long-term safety and performance with minimum cost. Nevertheless, majority of the existing studies has been dealing with deterministic optimization and has not involved uncertainties, which could lead to an unstable or even useless design in practice. In order to simultaneously enhance the performance and robustness of the fatigue life for a truck cab, a multiobjective optimization is proposed in this study. After validating the simulation model, different dual surrogate modeling (DSM) methods are attempted to overcome the limitation of classical dual response surface (DRS) method; and subsequently the most accurate model, namely dual Kriging (DKRG) in this case, is selected through a comparative study. Then, the multiobjective particle swarm optimization (MOPSO) algorithm is adopted to perform the optimization. Compared with traditional single objective optimization strategies which yield only one specific optimum, MOPSO allows producing a set of non-dominated solutions over the entire Pareto space for a non-convex problem, which provides designers with more insightful information. Finally, a multi-criteria decision making (MCDM) model, which integrates the techniques of order preference by similarity to ideal solution (TOPSIS) with grey relation analysis (GRA), is implemented to find a best compromise optimum from the Pareto set. The selected optimum demonstrated not only to improve the fatigue life of the truck cab, but also to enable the design less sensitive to presence of uncertainties. [ABSTRACT FROM AUTHOR]

During transport, due to vibration fruits and vegetables could be damaged. The vibration levels that transfer to fruits and vegetables may depend not only on vehicle characteristics (speed and suspension) and the road characteristics but also on the position of boxes packed in truck bed. The purpose of this research was to determine and analyze the vibration that occurs during truck transport as a function of box position and fruit position within the truck bed. For this purpose, two commercial trucks were used (with leaf-spring suspension and air-ride suspension). Test controllable factors includes: height positions of the container column (Bottom, Middle and Up), position of the container along the truck-bed (front axle and rear axle) and depth of fruit inside the container (Down and Top). The obtained values of the power spectral density were used to survey the effect of container positions on fruit vibration. RMS values were also obtained for different positions. The results showed that the power spectral density (PSD) was dependent on the position along the floor of the trucks. Higher vibration levels were recorded for fruits on top of the column. As the fruit height within a box increased, the vibration levels increased. ANOVA test results indicated that the considered factors significantly affected PSD values (Average PSD in the range of 0.1–5 Hz and peak PSD) and root mean square of acceleration ( P < 0.05). [ABSTRACT FROM AUTHOR]

Highlights: [•] Sandwich panels optimization model. [•] Sandwich panels design procedure. [•] Study of sandwich panels for automotive vehicle flooring. [•] Study of sandwich panels for truck cabin exterior. [Copyright &y& Elsevier]

There is evidence that season and truck/trailer design play important roles in pig welfare during transportation although little is known about their interaction and effect on pig behavior. This experiment was designed to examine the influence of season and truck/trailer design on the behavior during loading, transit, unloading, and lairage of market-weight pigs transported to slaughter. A total of 3,756 pigs were transported on either a 3-deck pot-belly trailer (PB; n = 181 pigs/wk in 8 experimental compartments) or a double-decker hydraulic truck (DD; n = 85 pigs/wk in 4 compartments) for 2 h to a commercial abattoir in summer and winter (6 wk in each season). Density on both vehicles was 0.40 m²/pig. Accounting for the number of pigs, loading took longer (P = 0.033) onto the DD than the PB, but season did not (P = 0.571) influence loading time. Pigs loaded onto the PB moved backward more (P = 0.003) frequently than those loaded onto the DD. The frequency of tapping by handler was the lone handling intervention affected by truck type, with more (P = 0.014) tapping needed to move pigs on and off DD than PB. During loading, pigs made more (P < 0.001) slips and falls, overlaps, 180° turns, underlaps, and vocalizations in winter compared with summer. On truck, more (P < 0.001) pigs were standing on the DD at the farm and in transit than on the PB whereas more (P = 0.012) pigs were lying in transit in summer than in winter. Pigs took longer to unload (P < 0.001) from the PB than the DD, but no difference between vehicles (P = 0.473) in latency to rest in lairage was found. Pigs slipped and fell more (P < 0.001) during unloading, took longer (P < 0.001) to unload, and had a shorter (P = 0.006) latency to rest in lairage in winter than summer. Vehicle design, in particular the presence of ramps, influenced pig behavior before, during, and after transportation, regardless of the season. Season affected loading and unloading behavior, especially in terms o slips and falls on the ramp, and differences in truck/trailer designs were also partly to blame for unloading times and lairage behavior. Ramps and changes in direction during unloading appear to slow down the handling process. [ABSTRACT FROM AUTHOR]

The article discusses the concept and utilization of monster trucks. It offers a review on the design and use of monster trucks, emphasizing on truck design, construction and the Science, Technology, Engineering and Mathematics (STEM) information that is essential in designing such innovations. It looks into activities that STEM educators in the U.S. can use to enhance how they teach science and engineering in their classes. It also discusses the entertainment factor and the logistics behind monster truck competitions.

The benefit of trolley truck systems is the substitution of the diesel fuel by the cheaper and more ecological electrical energy. Trolley trucks are powered by electricity from two overhead contact lines, where one is the supply and the other the return conductor. Such trolley trucks are used for haulage at open pit mining sites but could also be used for freight traffic at roadways in the future. Automatic guidance prevents the trolley-powered trucks from leaving the track and thus allows higher operating speeds, higher loading capacity, and greater efficiency. Radar is the ideal sensing technique for automatic guidance in such environments. The presented radar system with two-dimensional digital beamforming capability offers a compact measurement solution as it can be installed on top of the truck. Besides the distance measurement, this radar system allows to detect the location and inclination of the overhead contact lines by digital beamforming in two dimensions. Besides automatic guidance, the knowledge of the inclination of the overhead contact lines could allow automatic speed adaption, which would help to achieve maximum speed especially in hilly terrain. [ABSTRACT FROM AUTHOR]

The article discusses research concerning an anthropometric study of U.S. truck drivers, reporting that truck cab design models should be designed to provide efficient and safe ergonomic conditions for the U.S. truck driving population. According to the article, U.S. truck drivers are heavier, on average, than then general U.S. population. The multivariate accommodation model for cab design is mentioned.

Usually, the design optimization only deals with individual component of the truck because of the complex coupling relation between the cab and frame of the truck under assembly environment. Focusing on the complete optimal problem, a new conception of static modal stiffness was introduced and the sensitivity of static modal stiffness was define& The method for computing static modal stiffness sensitivities was also developed. Above proposed method has been applied to analyze and design the truck's cab, where a finite element model for full vehicle was used and the cab was divided into 15 super-elements. It is concluded that the obtained static modal stiffness sensitivities could be used to improve the design of the cab. [ABSTRACT FROM AUTHOR]

Abstract: This paper estimates the total embodied energy and emissions modal freight requirements across the supply chain for each of over 400 sectors using Bureau of Transportation Statistics Commodity Flow Survey data and Bureau of Economic Analysis economic input–output tables for 2002. Across all sectors, direct domestic truck and rail transportation are similar in magnitude for embodied freight transportation of goods and services in terms of ton-km. However, the sectors differ significantly in energy consumption, greenhouse gas emissions, and costs per ton-km. Recent pressure to reduce energy consumption and emissions has motivated a search for more efficient freight mode choices. One solution would be to shift freight transportation away from modes that require more energy and emit more (e.g., truck) to modes that consume and emit less (e.g., rail and water). Our results show there are no individual sectors for which targeting changes would significantly decrease the total freight transportation energy and emissions, therefore we have also looked at the prospect of policies encouraging many sectors to shift modes. There are four scenarios analyzed: (1) shifting all truck to rail, shifting top 20% sector mode choice, (2) based on their emissions, (3) based on a multi-attribute analysis, and (4) increasing truck efficiency (e.g., mpg). Increasing truck efficiency by 10% results in similar energy and emissions reductions (approximately 7% for energy and 6% for emissions) as targeting the top 20% of sectors when selected based on emissions, whereas selecting the top 20% based on availability to shift from truck results in slightly less reductions of energy and emissions. Implementing policies to encourage higher efficiency in freight trucks may be a sufficient short term goal while efforts to reduce truck freight transportation through sectoral policies are implemented in the long term. [Copyright &y& Elsevier]

The challenge of designing stability control functions for trucks is to guarantee robustness for all variations in truck and trailer combinations. The method proposed in this study can be used to quickly narrow down the number of truck and trailer combinations to a critical set to be evaluated with complex nonlinear simulation software or full-scale tests. To reach this goal, equations of motion are derived for single track linear vehicle models to understand the fundamental differences between the dynamic yaw performance of the truck and trailer combinations. The Hurwitz criterion is used to determine approximate analytical stability boundaries. It is shown that stability does not provide discrimination between combinations as most combinations are stable during normal driving conditions. In contrast, rearward amplification is a discriminatory performance measure. A frequency domain approach is used to study the fundamental differences between vehicle combinations. A comparison with complex nonlinear simulation model results indicates that the proposed method can be used to select critical vehicle combinations and to study the effect of parameter changes. [ABSTRACT FROM AUTHOR]

This paper describes the examination of the vehicle dynamics and stability of four-wheeled forklift trucks (FLTs) in cornering situations. Cornering at excessive speed is one major reason for fatal accidents with forklifts caused by lateral tipover. In order to increase the lateral stability of this kind of working machinery, the influence of certain important design properties has been studied using an appropriate vehicle simulation model and a driving simulator. The simulation model is based on a multi-body system approach and includes submodels for the propulsion system and the tyres. The driving behaviour of the operator has not been modelled. Instead, a driving simulator has been built up and a real human driver was employed for ensuring adequate and realistic model input. As there have not been any suitable standardised test manoeuvres available for FLTs, a new driving test has been developed to assess the lateral stability. This test resembles the well-known J turn/Fishhook turn, but includes a more dynamic counter-steering action. Furthermore, the dimensions of the test track are defined. Therefore, the test is better adapted to the driving dynamics of forklifts and reflects the real driver behaviour more closely. Finally, a parametrical study has been performed, examining the influence of certain important technical properties of the truck such as the maximum speed, the position of centre of gravity, rear axle design features and tyre properties. The results of this study may lead to a better understanding of the vehicle dynamics of forklifts and facilitate goal-oriented design improvements. [ABSTRACT FROM AUTHOR]

This paper presents the largest flaws in the design of big rig trucks. The aim of the paper is to raise awareness amongst truck manufacturers and to determine them to invest and research more in active security measures. [ABSTRACT FROM AUTHOR]

Abstract: The article mainly studies the YJ3128-type dump truck''s sub-frames, for the fatigue crack occurred in the Subframe witch has worked in bad condition for 3 to 5 months, the truck''s working conditions and the load features are researched, and ANSYS is used to analyze the stress of the sub-frame. According the deferent stress, the reason of the fatigue cracks’ occurring is researched too. At last an improvement and optimization to the structures of the frame is provided. For the stress of YJ3128-type dump truck there is no improved research methods and theoretical support, so the analysis in this paper and the proposed improvement scheme has important reference value. [Copyright &y& Elsevier]

This paper presents the results of an empirical study focused on the observation and analysis of an innovative design process. We have had the opportunity to observe and participate in the early phase of a new innovative project within a design office of a truck manufacturer. Our observations based on the actor-network theory highlight the importance of the various design rationales carried by the actors involved. The results of this study show the weakness and complexity of an innovative process within a highly constrained environment. We particularly show that carrying out innovation requires different viewpoints with regard to the object of the design to evolve along with the network of actors and the organisation involved. The issue of product and process integration involving knowledge transfer between actors throughout the design process is also discussed here. As a result, we highlight the importance of rethinking the interface role played by the material expert (in our case) and, in line with other works, we put forward the 'interface actor' as the key network actor involved during the early development phases. To provide the network and the interface actor with a means to share information and co-operate during these informal early design phases we propose some features of a new web-based information system and the basis for a debate on the idea lifecycle management concept as a solution to the issue of innovative idea information structuring. [ABSTRACT FROM AUTHOR]

The oil pan of large diesel engine trucks is identified as a significant contributor to their external noise radiation. This undesired broadband noise is caused by the oil pan's structural vibration and cannot be treated effectively by passive measures, especially in the low frequency range up to 500 Hz. In order to address this challenge, an Active Structural Acoustic Control (ASAC) system was to be realized within the European Union (EU) project "Intelligent Materials for Active Noise Reduction" for the oil pan of a Volvo MD13 truck engine. The technological demonstration was conducted in a laboratory test stand and employs piezoceramic patch actuators to alter the vibrations in a broadband noise reduction manner. The following paper focuses on the tasks of deriving actuator placement and estimating respective broadband sound power minimization capability. First, the oil pan's structural response to typical force excitation at its mounting points was analyzed through finite element simulation, and an actuator placement was derived. The estimation of its sound power minimization capability was then established based on computed structural frequency response functions and numerically derived radiation modes. Finally, the actuator layout was transferred to a serial production oil pan and adjusted by experimental observations. [ABSTRACT FROM AUTHOR]

We consider a cross-docking system in which there is no temporary storage and trucks are permissible not to load or unload all of their products but are held and come back to the dock to continue their tasks in case they are needed. Scheduling the trucks in such systems is a nondeterministic polynomial time-hard problem that motivates us to apply two well-known meta-heuristics-named genetic algorithm and electromagnetism-like algorithm for scheduling trucks with the objective of minimizing total flow time of the system, which is achieved through the best sequence of truck pairs. To attain the best robustness of these algorithms Taguchi’s robust design method is employed. To demonstrate the effectiveness of the proposed methods especially for large-sized problems, various test problems are solved, and the computational results show that our proposed methods perform better than Yu ()’s methods. [ABSTRACT FROM AUTHOR]

A way of parameterizing markets and applications for fatigue life assessments for trucks is discussed. A set of factors influencing the fatigue life of a truck is identified. The demands and usage of the concept are discussed, and a parametric model is constructed for the lateral loads using the identified factors. Some explicit results are given, which approximate the expected damage given by the parameters. These approximations are shown to give results close to the ones found directly from measurements. The properties of the classification and the underlying probability spaces are discussed, as well as the problem of how to handle the uncertainties in estimates and the variation of the parameters from one market to another. [ABSTRACT FROM AUTHOR]

Numerical and experimental investigations shed light on the root causes leading to the emergence and persistence of an acute metallic noise in rear wheel drive light truck drivelines. Sudden demands in engine output torque combined with the presence of lash zones give rise to a phenomenon that is onomatopoeically referred to as clonk. Its multi physics nature requires a comprehensive study, which includes rigid multi-body dynamics, flexible body oscillations, and noise radiation computation. The verification of numerical results is achieved through the design and implementation of a transient dynamic experimental rig, which comprises the complete drivetrain from the engine flywheel to the rear axle. Parametric studies reveal high-frequency contributions in the driveline vibration response of certain structural modes of the driveshaft pieces, which are induced by remote impact of meshing transmission teeth through backlash. The numerically predicted spectrum of vibration is in good qualitative agreement with the experimental measurements. Combined study of the aforementioned results reveals the components that amplify the clonk noise. [ABSTRACT FROM AUTHOR]

This paper describes a successful development of a new accessory rain protection for vans for which the principles of Dynamic Product Development (DPD) was used. The development was done and documented during 10 weeks. The result of the project is a prototype model for Opel Combo that unfolds automatically when the doors are opened (see figure 1 ). The work resulted in a Unigraphic model that makes it possible to easily make rain protections for other types of vans. What characterizes the new rain protection is that it is easy to mount, easy to use, possible to open doors 180° and that it takes a limited space when folded. Due to the materials recommended, it is environmental friendly. [ABSTRACT FROM AUTHOR]