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The 2018 Ultimate GD&T Pocket Guide explains the most common rules, symbols, and concepts used in geometric dimensioning and tolerancing. This one-of-a-kind reference guide includes more than 100 detailed examples to illustrate concepts. Numerous charts for quick reference provide explanations of each GD&T symbol, modifier, and more. This valuable on-the-job resource clarifies how to interpret standard-compliant technical drawings that use ASME Y14.5-2018.

COMVEC™ conference is the only North American event that addresses vehicles and equipment spanning on-highway, off-highway, agricultural, construction, industrial, military, and mining sectors.

Thermal Management Systems Symposium industry discusses latest regulatory impacts, applications to reduce engine emissions, conserve energy, reduce noise, improve the cabin environment, increase overall vehicle performance passenger, commercial vehicle industry.

This paper introduces the characteristics of the 4 wheel independent driving/4 wheel independent steering (4WID/4WIS) electric vehicle (EV). Models of Subsystems and the vehicle are constructed based on Matlab/simulink. The vehicle model allows the inputs of different drive torques and steer angles of four wheels. The dynamic characteristics of drive motors and steer motors are considered, and also it can reflect the vehicle longitudinal dynamics change due to the increase of the mass and inertia of the four wheels. Besides, drive mode selection function that is unique to this type vehicle is involved. Simulations and analyses of crab, oblique driving and zero radius turning which are the special conditions of 4WID/4WIS EV are conducted. The results show that the model can reflect the dynamic response characteristics. The model can be used to the simulation analyses of handling, stability, energy saving and control strategies verification of 4WID/4WIS EVs.

This paper describes the application of statistical techniques related to the condensation of computational models so that gradient based optimization procedures can be used more effectively. The adoption of these techniques is encouraged by the possibility of an important reduction in time and cost associated to the vehicle development process. A sophisticated computational model of a Mini-baja vehicle is defined in the virtual environment by means of CAD/CAE software, intending to provide the major information related to the study of its dynamic behaviour and to define the statistical surrogates (approximate models). The creation of the computational model deals with the determination of physical and geometric properties, and is fed by stiffness and damping parameters obtained through experimental procedures.

The paper addresses some aspects of an ongoing research on a commercial compact excavator. The interest is focused on the analysis and modelling of the whole hydraulic circuit that, beside a load sensing variable displacement pump, features a stack of nine proportional directional control valves modules of which seven are of the load sensing type. Loads being sensed are the boom swing, boom, stick and bucket, right and left track motors and work tools; instead, the blade and the turret swing users do not contribute to the load sensing signal. Of specific interest are the peculiarities that were observed in the stack. In fact, to develop an accurate AMESim modelling, the stack was dismantled and all modules analysed and represented in a CAD environment as 3D parts. The load sensing flow generation unit was replaced on the vehicle by another one whose analysis and modelling have been developed using available design and experimental data.

“Today, wearing parts are regularly subjected to abnormal loading conditions. They must be able to accept these conditions without failure. In continuous operations, unscheduled downtime greatly increases maintenance costs, not to mention the cost of lost production. White iron castings offer premium abrasion resistance for many of these applications, but are often not used due to the possibility of brittle failure and the difficulty of mechanical attachment. This paper discusses the properties and applications of a composite of martensitic white iron and mild steel. This laminate will accept medium to high impact without loss of service failure, and can be installed by mechanical means or with welded attachment.”

A simple contact-point based start of injection sensor has been developed for use in closed-loop injection timing control systems. The main element in this sensor is a highly durable thin film deposited by an advanced ion plating process. This sensor is expected to provide accurate detection of start of injection over all speed ranges. Sensor transient response in the feedback loop is also expected to be fast compared to other types of sensors. This detecting method can easily be applied to many kinds of injectors because of its simple structure. The durability has been confirmed by extensive testing.

Wet multiple plate clutches consist of friction plates, on which a friction material is bonded, and mating plates that are plain metal plates. Since the frequency and the range of load in the field of forklift trucks vary widely and are more severe than those for passenger cars, the wet multiple plate clutches on forklift trucks are often damaged. Damaged clutches that were returned from the field typically had 3 types of symptoms: 1.Only the friction material was damaged, 2.Only the mating plates were deformed, 3.Both symptoms were observed. It was clear that the cause of these symptoms depended on the difference of the operating application and the strength criteria of each part. This showed that a design guide for wet multiple plate clutches considering the strength balance between the two parts according to the work application was required. The relevant flow chart of this design process was proposed.

A software tool has been developed to aid designers and process engineers in the development and improvement of heat treat processes. This tool, DANTE™, combines metallurgical phase transformation models with mass diffusion, thermal and mechanical models to simulate the heating, carburization, quenching and tempering of steel parts. The technology behind the DANTE software and some applications are presented in this paper.

Taking a good longitudinal braking performance on flat and level road of tractor and semi-trailer combination as a target, in order to achieve an ideal braking force distribution among axles, while the vehicle deceleration is just depend on the driver's intention, not affected by the variation of semi-trailer mass, the paper proposes a model based vehicle mass identification and braking force distribution strategy. The strategy identifies the driver's braking intention via braking pedal, estimates semi-trailer's mass during the building process of braking pressure in brake chamber, distributes braking force among axles by using the estimated mass. And a double closed-loop regulation of the vehicle deceleration and utilization adhesion coefficient of each axle is presented, in order to eliminate the bad effect of mass estimation error, and enhance the robustness of the whole algorithm. A simulation is conducted by utilizing MATLAB/Simulink and TruckSim.

In automotive design and development, there are different stages for product design. In this fast changing scenario product design, digital verification of design (CAE), physical validation of the product and launching of the same in short time is important in product development life cycle of any new generation vehicle. This paper proposes a new approach towards development of a green-field platform for commercial vehicles by improving reliability of CAE and thereby reducing the need for prototype testing and hence shortening development cycle and costs - we call it “Hybrid Mule”. This Hybrid Mule has complete design intent under-body and engine-house while upper-body is made of simple representative tubular space frame. FRP skin panels are attached to this space frame to create a safe environment for test-driver. FRP skin also provides early feel of styling in running condition and evaluates basic ergonomics and visibility.

The earth's fossil energy is not limitless, and we should be taking advantage of the highly developed fields of science and technology to utilize it more efficiently and to create a fully environmentally friendly life. Considering the prodigious amount of vehicles in the world today, even a small improvement in their energy-saving performance could have a significant impact. In this paper, a new type of electro-hydraulic power steering (EHPS) system is described. It has two main advantages. First, it can significantly decrease the demand on the motor so that it can be used for a wider range of vehicles. Second, its pressure-flow characteristic can be programmed and is more flexible than hydraulic power steering (HPS) system. A prototype with a 500 W motor was applied to a truck with a front load of 2,700 kg, and static steer sweep tests were conducted to validate its feasibility.

A Rapid Duct Development and Diagnostic airflow simulation Tool (R3DT) has been developed that allows computational fluid dynamics (CFD) airflow simulations to be performed on complex three-dimensional (3D) Heating, Ventilation and Air Conditioning (HVAC) ducts quickly, easily and cost effectively. R3DT is a very automated approach to performing grid generation and CFD. It draws upon the strengths of the tools of ICEM CFD Engineering to create a fully tetrahedral mesh for complicated air duct geometries based on the original CAD data. It also uses FLUENT™ as the tetrahedral CFD solver. R3DT enables designers to make informed design decisions based on the predicted performance of their duct designs early in the development process, with the data still in CAD format. The concepts behind R3DT, as well as its application to a series of three-dimensional ducts with varying levels of geometrical complexity will be presented.

Shot peening has been used for half a century to combat metal fatigue and stress corrosion cracking in highly loaded machines and structures. Despite its success as a “fix” for service problems, there has been a reluctance to specify shot peening in new designs. This has been based on a lack of confidence, the uniformity and repeatability of the process. Much of this has been overcome with the introduction of computer-enhanced peening equipment, which monitors and controls key process parameters. Computer enhanced shot peening and its equipment are reviewed with emphasis on what it does and does not do. The successful marriage of conventional and computer enhanced peening is used for critical aircraft, turbine, nuclear power plant, and truck transmissions and its use promises to grow.

A cargo box is a key structure in a pickup truck which is used to hold various items. Therefore, a cargo box must be durable and robust under different ballast conditions when subjected to road load inputs. This paper discusses a Design for Six Sigma (DFSS) approach to improve the durability of cargo box panel in its early development phase. Traditional methods and best practices resulted in multiple iterations without an obvious solution. Hence, DFSS tools were proposed to find a robust and optimum solution. Key control factors/design parameters were identified, and L18 Orthogonal Array was chosen to optimize design using CAE tools. The optimum design selected was the one with the minimum stress level and the least stress variation. This design was confirmed to have significant improvement and robustness compared to the initial design. DFSS identified load paths which helped teams finally come up with integrated shear plate to resolve the durability concern.

This paper studies the effect of different longitudinal load conditions, roundabout cross-sectional geometry, and different semi-truck pneumatic suspension systems on roll stability in roundabouts, which have become more and more popular in urban settings. Roundabouts are commonly designed in their size and form to accommodate articulated heavy vehicles (AHVs) by evaluating such affects as off-tracking. However, the effect of the roadway geometry in roundabouts on the roll dynamics of semi-tractors and trailers are equally important, along with their entry and exit configuration. , Because the effect of the roundabout on the dynamics of trucks is further removed from the immediate issues considered by roadway planner, at times they are not given as much consideration as other roadway design factors.