ASME Conference Presenter Attendance Policy and Archival Proceedings

2016;():V012T00A001. doi:10.1115/IMECE2016-NS12.

This online compilation of papers from the ASME 2016 International Mechanical Engineering Congress and Exposition (IMECE2016) represents the archival version of the Conference Proceedings. According to ASME’s conference presenter attendance policy, if a paper is not presented at the Conference by an author of the paper, the paper will not be published in the official archival Proceedings, which are registered with the Library of Congress and are submitted for abstracting and indexing. The paper also will not be published in The ASME Digital Collection and may not be cited as a published paper.

Commentary by Dr. Valentin Fuster

Transportation Systems: Propulsion Systems and Fuels

2016;():V012T16A001. doi:10.1115/IMECE2016-66080.

For diesel vehicles equipped with a Diesel Particulate Filter (DPF), flow resistance (pressure drop) is a vital factor affecting power performance, fuel consumption and regeneration performance. Traditional methods for DPF pressure drop reduction mainly focus on developing a new filter material, optimizing its microstructure and structural parameters of gas channels. Although the above methods have greatly reduced the pressure drop, it is still difficult to meet the demand of increasingly stringent energy consumption and carbon emissions standards. Thus, improving the shape of connection (inlet and outlet) cones to further reduce pressure drop has become one of the important topics of DPF development.

In this paper, a simulation model of gas-particle two-phase flow through traditional connection cones has been established and wall-flow filter element is modeled with an equivalent porous material. The flow through DPF has been simulated with Fluent computational fluid dynamics (CFD) software under different exhaust emission velocities, expansion angles and ratios. The influence factors for flow uniformity and pressure drop in DPF have been analyzed. The variation tendency of pressure drop, flow velocity, vorticity, and turbulent kinetic energy in connection cones has been obtained. And then, based on calculation results and Non-Uniform Rational B-Splines (NURBS) theory, the fitting cure of optimum connection cones are drawn out at different expansion angles and ratios, compared with the calculation results of traditional connection cones, to deduce advantages of optimum connection cones on the flow uniformity and pressure drop.

Commentary by Dr. Valentin Fuster
2016;():V012T16A002. doi:10.1115/IMECE2016-66238.

With the rapid development of hybrid and electrically driven transportation systems, several concepts of electrically driven bicycles have been developed and introduced to the market. Also, for storage advantage and portability several versions of folding bikes are available in the market.

In this paper, the design, development and validation process for creating a version of a folding electrically assisted bicycle is presented. The designed, developed, and road tested bicycle concept is targeted for use by college students, exercise enthusiast, or for commuting to work. It is also intended as a means of transportation for those living in large cities with a considerable riding distance and a limited space to store a bicycle. In addition to being foldable, the electrically assisted bicycle is designed with a small footprint and a ride performance comparable to any normal city bicycle.

To achieve the design objectives, the process starts with identifying the key attributes such as portability, durability, drivability, maintainability, and safety. The steps for translating the targeted attributes to design criteria and product specifications are discussed. Consequently, the analysis and integration technical tasks needed to achieve the established bicycle specifications for both architectural and performance integration efforts are identified.

During the early stages of the design phase, different alternatives and off-the-shelf components are considered. Architectural and performance integration activities including detailed virtual modeling, simulations, and analyses are implemented to develop the bicycle and achieve targeted attributes within the design constraints.

For concept proofing, the designed concept was developed and road tested. Preliminary results of physical testing demonstrate the achievement levels of different targeted attributes. While some targets were achieved, the initial physical tests indicate that further design improvements are needed through additional development and validation iterations. These improvements could be achieved through adjustment of targets, weight reduction, and alternative materials.

Topics: Design , Bicycles
Commentary by Dr. Valentin Fuster
2016;():V012T16A003. doi:10.1115/IMECE2016-66312.

The gradual decline of oil reserves and the increasing demand for energy have resulted in automotive manufacturers developing new environmentally friendly vehicles such as electric and hybrid vehicles. Selection of the correct hybrid configuration for a given driving condition is very important since it affects the performance of the vehicle and its fuel economy. This paper focuses on a detailed parametric analysis of a Series Hybrid Electric vehicle (SHEV). The objective of this paper was to develop a SHEV powertrain by initial parameter matching and component sizing, followed by its optimization for given design constraints. This involved study and calculation of components power specifications based on vehicle dynamics. Initial parameterization was followed by optimization to meet the design objective. The simulation of the optimized SHEV was done in the software ADVISOR for an Indian driving cycle (IDC). Based on the simulation results, an optimum range of the powertrain components was established.

Commentary by Dr. Valentin Fuster
2016;():V012T16A004. doi:10.1115/IMECE2016-67181.

This study presents the design of an efficient catalytic converter with increased flow rate and minimum pressure drop using Computational Fluid Dynamics (CFD) techniques. Automobile engines produce undesirable emissions during the combustion process, such as NOx, CO, and unburned hydrocarbons. In addition to these harmful gases, particulate matter, such as lead and soot, is created. As a countermeasure, automobiles are equipped with catalytic converters, which are designed to play a vital role in eradicating emissions. However, due to the catalyst and filler materials found inside the converters, an increase in backpressure develops which leads to an increase in fuel consumption. The gas must pass through a low-porosity substrate to increase the reaction rate, which was simulated using parametric geometry. In this study, parametric simulations of the fluid flow were conducted, utilizing CFD techniques, to determine the optimum parameters that would create a minimal pressure drop while maintaining a high chemical reaction rate.

Commentary by Dr. Valentin Fuster

Transportation Systems: Transportation Systems Crashworthiness, Occupant Protection, and Biomechanics

2016;():V012T16A005. doi:10.1115/IMECE2016-65408.

During a vehicle crash, a major portion of the energy is absorbed by the frame structure. In general, stiffness and durability are considered as the primary criteria for design; but, not the crashworthiness of a frame structure. The purpose of this study is to evaluate the crash worthiness of a ladder frame structure. The effect of variation of bending stiffness and torsion stiffness of the ladder frame on the crashworthiness, specific energy absorption (SEA) and the peak load is investigated. Numerical analysis for frontal crash and stiffness of the ladder frame is done using LS DYNA® and CATIA®-Structural analysis software respectively. The numerical model for the frame frontal crash is validated by benchmarking the results obtained in this work with literature data. The height and the thickness of the frame side member (FSM) which absorbs most of the energy are taken as the design variables. The cross section of the FSM and cross members are taken as rectangular tubes with 90 mm height and 2 mm thickness as the base model dimension. The optimization is done to maximize the SEA of the frame with stiffness as the constraint. An optimized combination of design variables is identified using the response surface method. It is seen that the optimal point is found to be with the maximum height and minimum thickness; it is inferred that the crashworthiness parameters are bounded by the stiffness target set for the frame. Parametric analysis is done to investigate the influence of the design variables on the crash performance of ladder frame. The results show that increase in height by 50% from the base model will result in 4% increase in SEA and 60% reduction in peak loads when compared to a case with 50% increase in thickness. Torsion and bending stiffness was found to be 8% lesser and 62% higher respectively in case of 50% increase in height.

Commentary by Dr. Valentin Fuster
2016;():V012T16A006. doi:10.1115/IMECE2016-65774.

In order to improve the simulation accuracy of composite tube crush by finite element method, a nonlinear progressive damage model predicting the progressive inner-lamina damage of laminates is implemented. Each element of FEM is defined by the model. All parameters in this model were identified according to the published test data. The longitudinal crush was simulated by the solver of ABAQUS /explicit using the nonlinear progressive model. The result shows that the failure form pattern, peak force and energy absorption fit well with the published experimental ones. The robust optimization based on Six sigma technology and probability distribution of design variables is carried out to obtain an improved energy absorption property instead of deterministic optimization. This method can obtain an optimal composite tube with stable high energy absorption capability in a practical manufacture process.

Commentary by Dr. Valentin Fuster
2016;():V012T16A007. doi:10.1115/IMECE2016-65779.

Polymer-metal hybrid (PMH) by over-molding is a kind of weight reduction technology, in which the interface is formed by injecting liquid polymer directly on the surface of stamped metal and then curing under pressure. This technique takes the advantages of both the high strength and stiffness of metal and the complex geometry formability of polymer, and it is usually applied in structural components for weight reduction compared to all-metal structure. However, the different coefficient of thermal expansion (CTE) or hygroscopicity for polymer and metal in PMH structure may possibly produce additional interface stress and decrease joining strength degradation, and finally lead to local separation or complete fracture under various environmental loads. The present paper will provide an effective numerical method and investigate the influence of temperature and humidity on the onset and growth of crack, as well as the degradation of interface fracture toughness in PMH structures. Additionally analytical analysis provides qualitative guidelines and orientation for numerical method. The crack initiation is studied by the tensile test of a lap joint specimen, and the crack growth is studied by the DCB (Double Cantilever Beam) test and ENF (End Notched Flexure) test and of PMH specimen with an initial crack. It proves that both temperature and humidity has a great influence on interfacial strength, ultra bearing capacity and energy release rates of PMH structures, and their coupling has more influence than a single factor. The interface degradation degree of the GF30/PA66-HSS is lower than that of PA66-HSS under the same hygrothermal environment.

Commentary by Dr. Valentin Fuster
2016;():V012T16A008. doi:10.1115/IMECE2016-65876.

This work investigates the elasto-plastic response of platelets-like inclusions reinforced polymer composites showing an imperfect interface. The solution of the heterogeneous material problem is solved through a kinematic integral equation. To account for the interfacial behaviour, a linear spring model LSM is adopted, leading to an expression of the modified Eshelby’s tensor. As a consequence, the interfacial contributions with respect to the strain concentration tensor within each phase as well as in the average strain field are described by a modified version of the Mori-Tanaka scheme for the overall response. The non-linear response is established in the framework of the J2 flow rule. An expression of the algorithmic tangent operator for each phase can be obtained and used as uniform modulus for homogenisation purpose. Numerical results are conducted on graphene platelets GPL-reinforced polymer PA6 composite for several design parameters such as GPL volume fraction, aspect ratio and the interfacial compliance. These results clearly highlight the impact of the aspect ratio as well as the volume fraction by a softening in the overall response when imperfection is considered at the interface. Present developments are analytical-based solutions. They constitute a theoretical framework for further multi-scale applications in automotive. The crashworthiness simulation incorporating an influence of the interfacial behaviour on the strain energy absorption SEA is of interest.

Commentary by Dr. Valentin Fuster
2016;():V012T16A009. doi:10.1115/IMECE2016-66185.

Nowadays the use of thermoplastic materials has been increasing steadily, especially in automotive industries because of its positive effects on vehicle weight which is directly related to fuel consumption. These materials also provide a cost reduction for companies comparing with the steel or other similar materials. The other benefits of the thermoplastic materials are their high stiffness, excellent crashworthiness due to their energy-absorption characteristics, strength-to-weight ratios, fatigue and optimum design. Through their structure occurred by the polymer resins, thermoplastic materials can physically become a homogenized liquid when heated and hard when cooled. The thermoplastic materials are able to reheat, remolded and have good thermal and chemical stability. Also, these materials can be easily recycled which provides a lower environmental impact on the automotive industry. Due to the advantages of the thermoplastic materials, automotive industries have been using these technology in vehicle parts such as door panels, seat backs, load floor, engine cover, front end module, airbag housing, crash boxes, bumpers, instrument panel, air intake manifold, air duck, cross car beam, pedal brackets, gas tank carrier, etc. In order to produce the thermoplastic materials, a number of different methods (i.e. mechanical fastenings, ultrasonic assembly, metal inserts, snap fits, electromagnetic and heat welding, solvent/adhesive bonding) are proposed in the literature and most of them are successfully carried out in industrial applications. However, the identifying the joining technique according to the application area is an important issue to obtain appropriate material. Therefore, this paper presents a literature review of joining methods for thermoplastic materials and classifies the methods according to the structure of the joining technique. Within this context, more than 50 studies about joining techniques for thermoplastic materials are considered the methods are grouped into three main categories: chemical joining techniques, mechanical joining techniques, and thermal joining techniques. Chemical joining methods melt the surfaces of the materials by using a chemical solvent. By using the solvent, one plastic material is joined to itself or the material is joined to another type plastic that dissolves in the same solvent. In mechanical joining techniques, the materials are bonded by using some physical methods such as clipping, clamping, screwing, riveting, etc. Similarly, in thermal joining techniques the surface of the materials to be joined are heated and a pressure is applied until the thermoplastic material is formed. As a result of the review, the differences and efficiency of the joining methods are pointed out in the study with paired comparisons. Moreover, the real life applications of joining methods for thermoplastic materials in the automotive industry are presented. In this paper, effects of the joining techniques on pedestrian and occupant safety are also reviewed by taking into account the high-stress concentration factor, the inconvenient manufacturing process and, the reaction force peaks. Finally, the future challenges of the three categorized are summarized.

Topics: Joining
Commentary by Dr. Valentin Fuster
2016;():V012T16A010. doi:10.1115/IMECE2016-66523.

This paper aims to improve vehicle crashworthiness using vehicle dynamics control systems (VDCS) integrated with an extendable front-end structure (extendable bumper). The work carried out in this paper includes developing and analyzing a new vehicle dynamics/crash mathematical model and a multi-body occupant mathematical model in case of vehicle-to-vehicle full frontal impact. The first model integrates a vehicle dynamics model with the vehicle’s front-end structure to define the vehicle body crash kinematic parameters. In this model, the anti-lock braking system (ABS) and the active suspension control system (ASC) are co-simulated, and its associated equations of motion are developed and solved numerically. The second model is used to capture the occupant kinematics during full frontal collision. The simulations show considerable improvements using VDCS with and without the extendable bumper (EB), which produces additional significant improvements for both vehicle body acceleration and intrusion.

Commentary by Dr. Valentin Fuster
2016;():V012T16A011. doi:10.1115/IMECE2016-67236.

Research to develop new technologies for increasing the safety of passengers and crew in rail equipment is being directed by the Federal Railroad Administration’s (FRA’s) Office of Research, Development, and Technology. Crash energy management (CEM) components which can be integrated into the end structure of a locomotive have been developed: a push-back coupler and a deformable anti-climber. These components are designed to inhibit override in the event of a collision. The results of vehicle-to-vehicle override, where the strong underframe of one vehicle, typically a locomotive, impacts the weaker superstructure of the other vehicle, can be devastating. These components are designed to improve crashworthiness for equipped locomotives in a wide range of potential collisions, including collisions with conventional locomotives, conventional cab cars, and freight equipment.

Concerns have been raised in discussions with industry that push-back couplers may trigger prematurely, and may require replacement due to unintentional activation as a result of service loads. Push-back couplers are designed with trigger loads meant to exceed the expected maximum service loads experienced by conventional couplers. Analytical models are typically used to determine these required trigger loads. Two sets of coupling tests are planned to demonstrate this, one with a conventional locomotive equipped with conventional draft gear and coupler, and another with a conventional locomotive equipped with a push-back coupler. These tests will allow a performance comparison of a conventional locomotive with a CEM-equipped locomotive during coupling. In addition to the two sets of coupling tests, car-to-car compatibility tests of CEM-equipped locomotives, as well as a train-to-train test are also planned. This arrangement of tests allows for evaluation of the CEM-equipped locomotive performance, as well as comparison of measured with simulated locomotive performance in the car-to-car and train-to-train tests.

This paper describes the results of the coupling tests of conventional equipment. In this set of tests, a moving locomotive was coupled to a standing cab car. The coupling speed for the first test was 2 mph, the second test 4 mph, and the tests continued with the speed incrementing by 2 mph until the last test was conducted at 12 mph. The damage observed resulting from the coupling tests is described. The lowest coupling speed at which damage occurred was 6 mph. Prior to the tests, a one-dimensional lumped-mass model was developed for predicting the longitudinal forces acting on the equipment and couplers. The model predicted that damage would occur for coupling speeds between 6 and 8 mph. The results of these conventional coupling tests compare favorably with pre-test predictions. Next steps in the research program, including future full-scale dynamic tests, are discussed.

Topics: Locomotives
Commentary by Dr. Valentin Fuster
2016;():V012T16A012. doi:10.1115/IMECE2016-67356.

Computer finite element simulations play an important role in reducing the cost and time taken for prediction of a crash scenario. While interior crash protection has received adequate attention for automobiles, very little is known for commercial vehicle such as heavy trucks. The understanding of injury types for heavy trucks occupants in relation to different crash scenarios would help mitigation of the injury severity.

Finite element computer models of the heavy truck cabin structure, interior cabin components, anthropomorphic test device (ATD) (also called dummy) and passive restraint systems were developed and assembled to simulate head-on crash of a heavy truck into a rigid barrier. The researchers developed a computer simulation parametric evaluation with respect to specific seat belt restraint system parameters for a speed impact of 56.3 km/h (35 mph). Restraint parameter variations within this research study are seat belt load limiting characteristics, inclusion of seat belt pretensioner, and variation of seat belt D-ring location. Additionally an airbag was included to investigate another restraint system. For each simulated impact characteristic and restraint system variation, the occupant kinematics were observed and occupant risks were assessed.

Within the approximations and assumptions included in this study, the results presented in this paper should be considered as preliminary guidance on the effectiveness of the use of seat belt as occupant injury mitigation system.

Commentary by Dr. Valentin Fuster
2016;():V012T16A013. doi:10.1115/IMECE2016-67669.

Finite Element (FE) models are commonly used for automotive body design. However, even with increasing speed of computers, the FE-based simulation models are still too time-consuming when the models are complex. To improve the computational efficiency, SVR, a potential approximate model, has been widely used as the surrogate of FE model for crashworthiness optimization design. Generally, in the traditional SVR, when dealing with nonlinear data, the single kernel function based projection can’t fully cover data distribution characteristics. In order to eliminate the limitations of single kernel SVR, a mixed-kernel-based SVR (MKSVR) is proposed in this research. The mixed kernel is constructed based on the linear combination of radial basis kernel function and polynomial kernel function. Through the particle swarm optimization algorithm, the parameters of the mixed kernel SVR are optimized. Then the proposed MKSVR is applied to automotive body design optimization. The application of MKSVR is demonstrated by a vehicle design problem for weight reduction while satisfying safety constraints on X direction acceleration and Crush Distance. A comparison study for SVR and MKSVR in application indicates MKSVR surpasses SVR in model accuracy.

Commentary by Dr. Valentin Fuster
2016;():V012T16A014. doi:10.1115/IMECE2016-67671.

The Manual for Assessing Safety Hardware (MASH) defines crash tests to assess the impact performance of highway safety features in frontal and oblique impact events. Within MASH, the risk of injury to the occupant is assessed based on a “flail-space” model that estimates the average deceleration that an unrestrained occupant would experience when contacting the vehicle interior in a MASH crash test and uses the parameter as a surrogate for injury risk. MASH occupant risk criteria, however, are considered conservative in their nature, due to the fact that they are based on unrestrained occupant accelerations. Therefore, there is potential for increasing the maximum limits dictated in MASH for occupant risk evaluation.

A frontal full-scale vehicle impact was performed with inclusion of an instrumented anthropomorphic test device (ATD). The scope of this study was to investigate the performance of the Flail Space Model in a full scale crash test compared to the instrumented ATD recorded forces which can more accurately predict the occupant response during a collision event.

Results obtained through this research will be considered for better correlation between vehicle accelerations and occupant injury. This becomes extremely important for designing and evaluating barrier systems that must fit within geometrical site constraints, which do not provide adequate length to redirect test vehicles according to MASH conservative evaluation criteria.

Topics: Risk assessment
Commentary by Dr. Valentin Fuster
2016;():V012T16A015. doi:10.1115/IMECE2016-67754.

The purpose of this research was to develop a 31-inch (787 mm) W-beam guardrail system to be placed with a 3H:1V slope in front of the barrier. The structural capacity and the occupant risk factors of such a proposed guardrail system were evaluated with respect to the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) TL-3 criteria. Finite element computer models of new guardrail designs for evaluation when placed on a 3H:1V sloped terrain configuration were developed and impact simulations were conducted to support their evaluation according to MASH standards evaluation criteria.

Three barrier designs for placement on a 3H:1V slope were suggested for evaluation through predictive computer simulations. All systems appear to be crashworthy and likely to pass safety evaluation criteria required for MASH. Depending on the desired system post distance location from the 3H:1V slope break, the researchers recommend evaluation of selected design through full-scale crash testing according to MASH TL-3 criteria. The information compiled from this research will provide the Federal Highway Administration (FHWA) and State Departments of Transportation with a W-beam guardrail design as a crashworthy system to be placed with a 3H:1V slope in front of a barrier.

Commentary by Dr. Valentin Fuster

Transportation Systems: Transportation Systems Dynamics and Controls

2016;():V012T16A016. doi:10.1115/IMECE2016-66307.

In this paper, a collision avoidance algorithm (CAA) has been proposed using variable time headway considering heterogeneous traffic. The time headway used in the proposed CAA was tuned based on the traffic scenarios, the host vehicle’s load conditions and the type of the lead vehicle that the host vehicle encounters in the traffic. The proposed variable time headway would help to avoid the intervention of the collision avoidance system during normal driving and gain driver’s acceptance. The CAA was evaluated using a hardware-in-the-loop (HiL) experimental set-up integrated with the vehicle dynamic simulation software IPG/TruckMaker® for different categories of lead vehicles such as 2/3 wheelers, passenger cars, light commercial road vehicles (LCVs) and heavy commercial road vehicles (HCVs). From the results, it was observed that while following a HCV, a smaller time headway was sufficient to prevent a collision compared to following a passenger car, LCV and 2/3 wheeler.

Commentary by Dr. Valentin Fuster
2016;():V012T16A017. doi:10.1115/IMECE2016-66355.

Regenerative braking is applied only at the driven wheels in electric and hybrid vehicles. The presence of brake force only at the driven wheels reduces the lateral traction limit of the corresponding tires. This impacts the vehicle lateral response, particularly while applying the regenerative brake in a turn. In this paper, a detailed study was made on the impact of regenerative brake on the vehicle lateral response in front wheel drive and rear wheel drive configurations on dry and wet asphalt road surfaces. Simulations were done considering a typical set of vehicle parameters with the IPG CarMaker® software for different drive conditions and braking configurations along the same reference track. The steering wheel angle, yaw rate, lateral acceleration, vehicle slip angle, and tire forces were obtained. Further, they were compared against the conventional all wheel friction brake configuration. The regenerative braking configuration that had the most impact on vehicle lateral response was analyzed and response variations were quantified.

Commentary by Dr. Valentin Fuster
2016;():V012T16A018. doi:10.1115/IMECE2016-66470.

The occurrence of perturbations in traffic flow may lead to the formation of stop-and-go waves traveling upstream, or to traffic jams. Therefore, traffic flow stability analysis is considered to be one of the fundamental problems in traffic flow theory, and a lot of effort has been spent to analyze the formation and evolution of such traffic flow instabilities. Recent advances in the field of Vehicle Automation and Communication Systems (VACS), including the most widespread Adaptive Cruise Control (ACC) systems, may consist a possible solution in reducing the magnitude or even eradicating the development of such traffic flow instabilities. This paper aims to perform a nonlinear stability analysis of a second-order macroscopic traffic flow model, which was recently developed by the authors for the simulation of the traffic flow of ACC-equipped vehicles, and identify the ways that ACC systems affect the stability of the flow, in relation with large traffic disturbances around the equilibrium state. Numerical simulations are additionally conducted, to validate the derived stability conditions.

Commentary by Dr. Valentin Fuster
2016;():V012T16A019. doi:10.1115/IMECE2016-67084.

Autonomous vehicles provide an opportunity to reduce highway congestion and emissions, while increasing highway safety. Intelligently routed vehicles will also be better integrated with existing traffic patterns, minimizing travel times. By reducing the time wasted in traffic; harmful emissions will consummately be reduced. Well-designed autonomous control systems provide for increased highway safety by reducing the frequency and severity of traffic accidents caused by driver error. In order to achieve this, a robust multi-layered control system must be designed, which minimizes the likelihood of computer error, while enabling seamless transition to and from human control.

Autonomous vehicle navigation systems rely on accurate and timely sensor inputs to determine a vehicle’s location, attitude, speed, and acceleration. This paper describes a telemetry sensor fusion approach, which enables an autonomous vehicle to navigate, complex intersections, based on previously planned paths and near field sensors. This reduces computational overhead on the vehicle’s computer, and provides real time redundancy for system errors or delays. In conjunction with a full complement of environmental sensors, this path planning - path following approach enhances the robustness of autonomous vehicle operating models.

This research supports the rapidly expanding field of autonomous automobiles by examining novel concepts for robust telemetry sensor fusion between inertial, GPS, and wheel speed sensors, which allows for error correction and enhanced positional accuracy, when compared to conventional navigation algorithms.

Topics: Sensors , Vehicles , Errors
Commentary by Dr. Valentin Fuster
2016;():V012T16A020. doi:10.1115/IMECE2016-67123.

Traditionally speaking, prototype tires are designed, and then tested on an experimental basis to evaluate performance. Using finite element analysis instead allows tire design parameters to be modified at will and underperforming architectures to be ruled out. This paper characterizes the dynamic response of a tubeless pneumatic vehicle tire as it is exposed to sudden impact and determines conditions under which failure would occur. Three cases were studied using a 175SR14 passenger tire, since passenger tires are most commonly used and impacts are more substantial on smaller tires. ABAQUS finite element program was used to perform nonlinear transient dynamic three-dimensional finite element analyses for three commonly tire encountered conditions. The first case, direct curb impact, determined that a safe inflation pressure range for tire velocities exists between 10 and 60 km per hour (kph). The second case, angled curb impact, found a smaller range of 10 to 40kph. The third case, impact with a pothole, found that at low inflation pressures, less stress is produced at higher velocities; increasing inflation pressure results in a transition point, causing larger stresses to be produced at higher velocities. From these analyses, several conclusions are drawn: inflation pressures below 100KPa do not produce a useful relationship between tire velocity and stress; thicker sidewalls help shield the tire from impact failure; and it is better for the tire to accelerate past a pothole in the 30 to 70kph range.

Topics: Simulation , Tires
Commentary by Dr. Valentin Fuster

Transportation Systems: Transportation Systems Technologies, Design, and Simulations

2016;():V012T16A021. doi:10.1115/IMECE2016-65090.

This paper presents a model reference adaptive control (MRAC) approach to enhance the lateral stability of car-trailer systems. To this end, a 3 degrees of freedom (DOF) linear yaw-plane car-trailer model was developed as a “reference model”. The yaw rate of leading and trailing units of the reference model were used as the target states to control and stabilize a virtual vehicle plant represented by a 5 DOF linear yaw-roll car-trailer model. A Lyapunov-based controller was designed to handle the lateral stability of the car-trailer dynamical system. The model parameters and operating conditions of the system were predefined while designing the controller. The effectiveness of the adaptive controller for improving the lateral stability of car-trailer systems was demonstrated under a simulated multiple cycle sine-wave steering input maneuver. It was observed that the lateral stability of car-trailer system was improved by controlling respective yaw rates of the car and the trailer, using model reference adaptive control approach in conjunction with Lyapunov stability criterion.

Commentary by Dr. Valentin Fuster
2016;():V012T16A022. doi:10.1115/IMECE2016-65381.

To address concerns of how mobile proximity detection systems will adapt to underground mobile haulage vehicles, researchers have collected and categorized data on the parameters of 145 mine haulage vehicles in 5 categories including load-haul-dump, shuttle car, roof bolter, haul truck, and mobile coal haulage (face drill, production drill, and others.) Statistical methods were used to determine the appropriate representative vehicle for each category. These representative vehicles’ parameters and characteristics could then be used to develop a dynamic model that predicts their dynamic behavior on an underground haulageway surface. These models can be used in conjunction with worker escapability data and/or interaction with other vehicles to provide insight as to whether or not the proximity detection systems will be adequate for the underground mining workplace.

Commentary by Dr. Valentin Fuster
2016;():V012T16A023. doi:10.1115/IMECE2016-65430.

Modular Design has made an important contribution to the industrial evolution, increase of quality of products and goods and to economic development. It has produced an important evolution in design (technical modularity), in the organization of production and of companies. It allowed going beyond vertical integration, by fostering vertical specialization in both manufacturing and innovation. Several authors are appointing important question on the modular approach. They move observations of different nature concluding that the enthusiasm for modularity has gone too far. One of the critical positions sustains that modular design has imposed technical choices that conflicts with energy efficiency in vehicle design such as a gradual increase of weight over time and the consequent reduction of potential gains in terms of energy consumption and environmental footprint of vehicles. This paper agrees with some arguments of the revisionist literature in cautioning against errors that can be produced by a pervasive modularity. But it moves from an energetic analysis and has not the objective of defining an alternative theory. More modestly, it aims to present a possible way for coupling modular design with energy optimization in the case of an electric vehicle. The initial inspiration can be of this case study is Bejan’s preliminary modular definition of constructal optimization, which can fit perfectly with industrial modular design. Even if this modular optimization does not have the ambition of defining the best possible solution to a complex design problem, such as Multidisciplinary Design Optimization has, it allows defining configuration that can simply evolve over time by mean of a step by step optimization of the critical components that influences the behavior of a complex industrial system. It reveals then to be applicable to the concept of vehicle platform that is today widely in use. The specific test case is the design of an electric city vehicle which has been optimized by a step applying this modular optimization approach. This paper has also a romantic value because it ha taken the move from the emotion that has been caused by the stop to the production of an extraordinary myth, such as Land Rover Defender. 70 years of production without important changes means that Defender has been not only the most successful British vehicle, but also that it has been a fundamental part of our way of living. This extraordinary longevity is an extraordinary technical and cultural heritage to our time. This decision forces the authors to try to analyze the conceptual modular design of a vehicle that can compete with Defender in terms of use and performances. Results have been surprising demonstrating that the use of industrial grade components and their accurate choice will allow defining new vehicle platforms that can radically improve energy efficiency of vehicles.

Commentary by Dr. Valentin Fuster
2016;():V012T16A024. doi:10.1115/IMECE2016-65536.

Since 1984, remote controlled continuous mining machines (CMM) have caused 40 crushing and pinning fatalities in the United States. Due to limited space in the underground environment and visibility needs, CMM operators typically work close to the machine which exposes them to the danger of being struck or pinned by it. Because of these fatalities, the Mine Safety and Health Administration (MSHA) has published a rule requiring proximity detection systems (PDSs) on all CMMs except for full-face machines. To test PDS performance, researchers at the National Institute for Occupational Safety and Health (NIOSH) conducted a series of field tests in underground coal mines throughout the United States on CMMs equipped with PDSs. The field tests collected data under a variety of conditions to evaluate the warning and shutdown zone performance of these systems. A baseline test condition was measured when the machine was operating in non-mining mode. Three additional conditions discussed in this paper include testing of the PDS while the machine was operating in mining mode, examining the possibility of parasitic coupling to the trailing cable, and examining the effects of the presence of a shuttle car. The results of this study indicate that the average warning and stop zones vary minimally between non-mining mode and trailing cable influence measurements, as well as between the mining mode and shuttle car presence tests. A majority of the measurements for warning and stop zones showed repeatability within +/− 5 inches (12.7 cm). Additionally, parasitic coupling to the trailing cable was not experienced during this field testing. However, these results show that the range of stop zone measurements varied by 4.7 ft on average and as much as 11.7 ft in different field sites. This is most likely due to individual preferences by operators during installation when the warning and stop zone distances are set. While a PDS should effectively stop a CMM when an operator gets too close to the machine, the large variations between field test measurements indicate that there is a wide variation of performance established during system installation.

Commentary by Dr. Valentin Fuster
2016;():V012T16A025. doi:10.1115/IMECE2016-65648.

This paper presents a parametric study of linear lateral stability of a car-trailer (CT) combination in order to examine the fidelity, complexity, and applicability for control algorithm development for CT systems. Using MATLAB software, a linear yaw-roll model with 5 degrees of freedom (DOF) is developed to represent the CT combination. In the case of linear stability analysis, a parametric study was carried out using eigenvalue analysis based on a linear yaw-roll CT model with varying parameters. Built upon the linear stability analysis, an active trailer differential braking (ATDB) controller was designed for the CT system using the linear quadratic regulator (LQR) technique. The simulation study presented in this paper shows the effectiveness of the proposed LQR control design and the influence of different trailer parameters.

Topics: Stability
Commentary by Dr. Valentin Fuster
2016;():V012T16A026. doi:10.1115/IMECE2016-66162.

When traveling through heavy traffic, vehicles lose a large amount of their kinetic energy. These losses can be attributed to various sources such as the roll friction of the tires against the road pavement. According to the Federal Highway Administration, there are an average of 304,000 cars a day travelling on the US-75 near the Dallas Fort Worth Arlington area in Texas. With so much available energy being wasted, it is essential to find a different way to harness losses so that they can be recycled. The purpose of this research project is to design a system that will harvest some of this lost energy using a set of pneumatic cylinders built into the road. The cylinders will have a dome shape that extends slightly above the surface of the road. As cars pass over this dome the cylinder will retract and compressed air will be sent through a pneumatic system, to an air tank where it is stored. The energy generated by the air stored in the cylinder can be used to drive a pneumatic motor that can turn a generator. The generator could then be used for multiple purposes such as: charge a battery, power a toll booth or other near highway structures. The compressed air stored in the tank may be used for other applications. This is useful due to the fact that almost every industry from the medical industry to the food industry use compressed air to power their pneumatic tools. The pneumatic cylinder will be used in areas of high traffic such as when a car approaches a toll booth, or entrances and exits of multi-level parking garages. The pneumatic cylinder and the associated air flow system using a CAD and a pneumatic software. The behavior of the system could then be tested and be better understood. After the initial simulation testing, a physical prototype has been built in order to gather practical data that can be compared to the simulations. Based on the gathered data on the prototype an assembly of numerous road rumbles can be built and tested on real streets. It is expected that a high pressure will be built in the tank using the prototype. Once pressure is built in the system data will be generated using various instruments, which will show pressure versus time, and pressure versus number of strokes so that the system can be better understood during the testing period. This data will then be used to determine the efficiency, and viability of the proposed system in generating compressed air as a form energy.

Commentary by Dr. Valentin Fuster
2016;():V012T16A027. doi:10.1115/IMECE2016-67130.

Ground vehicles with autonomous navigation require medium range external sensing for early obstacle detection and terrain mapping. Both are essential for path planning. The conventional method for accomplishing this is achieved by very complex and expensive LiDAR sensors with 32 to 64 individual lasers rotating rapidly and taking readings from the top of the vehicle. Our most pertinent research question however is to ascertain if a less cumbersome and cost effective setup of a small number of single beam laser rangefinder sensors can accomplish the same task. Our current method to achieve this is to sweep the sensors a variable number of steps along a predetermined angle. The information obtained is used to develop a complete and detailed view of the world around the autonomous vehicle.

This paper is focused on a small laser ranger finder attached to a programmable pan-tilt mount positioned at the front of the autonomous vehicle. These were chosen as they are the most viable type of sensors for this process due to low interference and also because long range accuracy data can be obtained with reasonable power consumption. The sensors and mount are connected to a microcontroller which gathers position and distance information of significant objects in the path of the vehicle, in polar coordinates. This information is then converted to more useful Cartesian coordinates and plotted on a point cloud which is then used for path planning in real time.

Future work will include sensor fusion of this system and an image sensor for detection of relevant objects such as traffic signs. Such systems establish a distance from the vehicle as well as distinguish them by shape and color.

Topics: Lasers , Sensors , Vehicles
Commentary by Dr. Valentin Fuster
2016;():V012T16A028. doi:10.1115/IMECE2016-68013.

The market of the hybrid electric vehicles has been increasing for several years. Different commercial EV and PHEV solutions are available for passenger cars and light vehicles for freight deliveries. However, the market of heavy trucks still regards traditional ICE vehicles powered by diesel oil fuel. The recent interest for electric solutions have been pushing the development of the hybrid solutions, but only micro-hybrid systems are considered feasible for heavy truck applications. The proposed research aims to define a methodological approach with a virtual model in order to simulate the behavior of a hybrid heavy truck. The scope of this research is the feasibility analysis of a retrofit hybrid heavy truck. A real driving cycle has been used in order to obtain reliable results in terms of cost, energy consumption and gas emission. The layout of the hybrid system has been proposed as well as the sizing of battery and electric motor. A commercial tool has been used for the vehicle modelling and simulation. As a test case, an 18-ton truck has been analyzed with a 10-liter diesel engine. Firstly, the simulation of the diesel truck has been reproduced considering the real driving cycle data. Secondly, the simulation activity has been focused on the evaluation of the hybrid system behavior by investigating different battery sizes with the same boundary conditions related to the real driving cycle.

Topics: Modeling , Roads
Commentary by Dr. Valentin Fuster
2016;():V012T16A029. doi:10.1115/IMECE2016-68128.

For the vehicle to move forward, the engine has to be connected to driving wheels so as to propel the vehicle. The engine rotates at relatively high speeds, while the wheels are required to turn at slower speeds. The torque requirements of the vehicle vary as per the prevailing conditions of load, terrain etc. Gear box provides different gear ratios between the engine and the driving wheels, to suit the varying road conditions such as when climbing hills, traversing rough road, moving on sandy road or pulling a load. The required gear shift for providing varying torque requirements can be obtained either manually or automatically. Automatic gear shifting mechanism is a concept implementing an embedded control system for actuating the gears automatically without human intervention. The automation is achieved by using a microcontroller and suitable sensor and actuator hardware. Whenever the speed of the vehicle increases or decreases beyond a pre-defined set of values, the microcontroller based control system actuates the clutch as well as the gear and helps maintain a steady operation of the automobile. The concept of automatic gear change is applied in this work to a 4-stroke, manual transmission motorcycle. The clutch is actuated by means of a DC Motor actuated mechanism and gear lever is actuated by means of the spring loaded solenoid actuator, both controlled by a microcontroller based circuit, programmed to read the signals from an inductive proximity sensor which senses the actual speed of the wheel. The system design and development is described in this paper with control circuit and control logic.

Commentary by Dr. Valentin Fuster

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