Search Results

For years, producers of low to medium volume products of high unit cost have been faced with the questions-“How much do we test?” and “What if we don't?” Today, manufacturers cannot compete in the market if these questions are not answered. This paper presents a methodology for answering these questions quantitatively. It applies Bayes Theorem of “apriori knowledge” to generate a probabalistic model of the new product testing task. It uses the existing knowledge and expertise within the organization and a simple matrix technique to determine the testing needs for the project at hand. This paper is intended to address the issues of durability and reliability of new products that are manufactured in relatively low volumes, such as Lift Trucks and Farm Equipment and/or products of high unit cost such as construction or off highway machinery.

Four different off-highway truck hydraulic steering systems with varying complexity are presented. The reliability of each type of system is compared showing the effects of redundancy of components. The importance of system configuration is brought out to offset the adverse effects of a low reliability component. The advantages of a stored energy system in providing an emergency steering capability and in reducing the size of the pump are discussed.

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.

Several highly technical skills are required to design and develop a self-propelled vehicle. One such skill is to design or select the appropriate size drive train. The more accurately this can be accomplished, the more significant will be the savings in development cost. Various references are available on the theoretical approach; however, a significant unknown is the relationship to practical applications. Zahnradfabrik Friedrichshafen AG has over many years of experience developed a computer program that can reliably assess the service life of power train designs. The reliability of this approach has been proven by both vehicle manufacturers and end users.

This paper discusses a simplified analytical/experimental method for evaluating and designing large buses and motor coaches for rollover protection. The proposed method makes use of the work-energy principle in analyzing the energy-absorbing capacity of the roof and sidewall structure of the vehicle. The basic structural unit is treated as a nonlinear, elastoplastic, 4-bar linkage, with the links connected at hinge points. During rollover, the deformation of the structure is focused at these hinge points and energy absorption is achieved through plastic bending and rotation of the hinge material. The proposed method allows the evaluation and design of these plastic hinges to achieve the energy-absorbing requirements for the vehicle. This paper demonstrates the proposed methodology by evaluating an exemplar large bus design against the European ECE-R.66 rollover design standard.

In a diaphragm used for an accumulator, the relationship between design factors and durability in low temperature is discussed from the occurrence of buckling phenomenon through the observation results. The durability of the diaphragm which has a sandwich structure of rubber and resin films, is greatly influenced by the buckling phenomenon which occurs during deformation of the diaphragm when used for an accumulator in low temperature condition.

Turbulence is known to influence the aerodynamic and aeroacoustic performance of ground vehicles. What is not thoroughly understood are the characteristics of turbulence that influence this performance and how they can be applied in a consistent manner for aerodynamic design and evaluation purposes. Through collaboration between Transport Canada and the National Research Council Canada (NRC), a project was undertaken to develop a system for generating road-representative turbulence in the NRC 9 m Wind Tunnel, named the Road Turbulence System (RTS). This endeavour was undertaken in support of a larger project to evaluate new and emerging drag reduction technologies for heavy-duty vehicles. A multi-stage design process was used to develop the RTS for use with a 30% scale model of a heavy-duty vehicle in the NRC 9m Wind Tunnel.

This paper describes a methodology for design and development of On-Board Diagnostic system (OBD) with an objective to improve current reliability process in order to ensure design & quality of the new system as per requirement of commercial vehicle technology. OBD is a system that detects failures which adversely affect emissions and illuminates a MIL (Malfunction Indicator Lamp) to inform the driver of a fault which may lead to increase in emissions. OBD provides standard and unrestricted access for diagnosis and repair. Below given Figure 1 shows the working principle of OBD system. The exhaust emission of a vehicle will be controlled primarily by Engine Control Unit (ECU) and Exhaust Gas After Treatment Control (EGAS CU). These two control units determine the combined operating strategies of the engine and after treatment device. Figure 1 Modern Control Architecture for OBD System in Commercial vehicle [1]

This paper is divided into two parts: Part 1 - Systems engineering fundamentals Part 2 - Engine cooling design from a systems engineering perspective In Part 1, we explain how the task of designing a complex system can be made easier by the application of Systems Engineering principles. (This part is self contained and may be of general interest to those who have no special interest in engine cooling). Systems Engineering provides three key benefits: It facilitates communication: Requirements define the problem, they allow team members to see their own work in context Key information is standardized and made easier to visualize and verify. An “audit trail” is maintained ensuring that important information is documented, and human memory is no longer relied on for important decisions. Translates requirements into design.

A new unitized heavy duty axle oil seal (Figure 1) has been developed that meets in whole objectives that are demanded by the modern truck owner. These objectives are, unitized assembly, simplified no tool installation, damage resistance, external contaminant exclusion, use in aluminum hubs and a proven reliability and ultimate life capability. This paper discusses the advanced design which is supported by extensive laboratory and field testing in excess of one hundred million vehicle miles. Typical laboratory testing included intensive functional life bench testing, comparative dust testing and cold follow-ability and fracture tests. The field testing has made use of a broad array of vehicle applications from continuous duty coast-to-coast transport in Canada to short haul quarry pit and numerous city traffic fleets. The results of the laboratory and field testing are discussed, revealing how this design has met the demands of the modern seal user.

A new oval test track will be designed, constructed and operated in a manner that will successfully pull-together representatives from virtually all of the key interests in dealing with the challenging issues of highway pavement and truck durability. With construction scheduled to begin in the Summer of 1998 and completion scheduled for late 1998 or early 1999, the mission and commitment for this venture is to pull-together the people from several state DOTs, respective universities, and, of vital importance, the truck manufacturing industry. Results from these tests, over a period of a few years, will provide answers that not only greatly improve performance of hot mix asphalt pavements in all state DOTs, but also efficiently and productively address issues of durability and wear performance of medium / heavy duty trucks and key components.

A web based software program has been developed to do a Finite Element (FE) analysis of a simplified driveline system. In the past, an expert analyst had to make a Finite Element Model, analyze and then report results. It has been observed that this process is time consuming besides the difficulties of doing quick parametric studies, geographical location of designers, analysts, etc. The web-based software program aims to solve these issues. The designer could get analytical & Finite element results anywhere around the world (where the designer has access to the web) without any expertise in FE modeling. This software is a joint effort of Engineering and Information Technology (IT) software groups. It is based on Active Server Page (ASP) technology and MSC/NASTRAN technologies combined. Input data deck is prepared from user inputs and submitted over the internet to a remote system, solved and results are retrieved and plots shown in minutes, instead of days earlier.

This SAE course is for individuals in quality management systems, implementation, and auditing to the AS9100:2016 series of standards.

This 1-day introductory-level course builds on fundamentals of geometric dimensioning and tolerancing and teaches the impact of GD&T on the manufacturing process. The course focuses on the basic requirements of engineering drawings, size dimensions, form tolerances, and the datum system, as well as how tolerancing requirements affect production. Each participant receives: A GD&T for Manufacturing Workbook,  A GD&T Ultimate Pocket Guide (2009), and Class handouts.  Newly acquired learning is reinforced with numerous practice exercises.

Durability tests of commercial vehicles are performed on road running uphill and downhill as well as on flat roads; these tests take very long time and have high costs. To lower test time and costs, it is proposed to accelerate the durability tests of commercial vehicles power trains by using a Towing Trailer with an electromagnetic (EM) brake, developed in Brazil, simulating uphill. This Trailer was already presented [1], [2] for cooling test simulation at 20 km/h on commercial vehicles up to 250 HP. In the cabin (cab) of the vehicle under test, there are the braking level control and a laptop, which receives wireless and registers the operational parameters of the Towing Trailer. The GPS in the truck cabin (cab) supply information such as time, speed, latitude and longitude allowing the control of the route.

In the modern automotive sector, durability and reliability are the most common terms. Customers are expecting a highly reliable product but at low cost. Any product that fails within its useful life leads to customer dissatisfaction and affects the reputation of the OEM. To eradicate this, all automotive components undergo stringent validation protocol, either in proving ground or in lab. This paper details on developing an accelerated lab test methodology for steering gearbox bracket using fatigue damage and reliability correlation by simulating field failure. Initially, potential failure causes for steering gearbox bracket were analyzed. Road load data was then acquired at proving ground and customer site to evaluate the cumulative fatigue damage on the steering gearbox bracket. To simulate the field failure, lab test facility was developed, reproducing similar boundary conditions as in vehicle.

This paper describes an integrated dynamic simulation and RPC (Remote Parameter Control) shaker test approach that accelerates product development of structural components. The simulation is based on the principle of random vibration and is used for optimizing the design in the early stages of the design process. Once the prototypes are built, RPC shaker test is used to verify the structural integrity of the optimized designs. The benefits of this integrated approach are demonstrated using a tractor seat development example. The simulation was able to pin-point potential failure locations and estimate the fatigue life. The design was optimized using only one design iteration.

The application of accelerated testing theory is a difficult proposition, yet one that can result in considerable time and cost savings, as well as increasing a product's useful life. In Accelerated Testing: A Practitioner's Guide to Accelerated and Reliability Testing, readers are exposed to the latest, most practical knowledge available in this dynamic and important discipline. Authors Bryan Dodson and Harry Schwab draw on their considerable experience in the field to present comprehensive, insightful views in this book. Development and quality assurance tests are defined in detail and are presented from a practical viewpoint. Included are testing fundamentals, plans and models, and equipment and methods most commonly used in accelerated testing. Individuals seeking to evaluate and improve the design lives of components and systems will find this book a valuable reference, with special attention being paid to testing in the mobility industries.