Search Results

Wheel end bearing is one of the critical components of the vehicle as it shares the loads & support wheel rotation simultaneously. ...In wheel end, taper roller bearings are used. It helps to withstand both vertical & lateral loads imparted during cornering. ...In wheel end bearing systems bearings are kept at distance w.r.t to each other based on position of load line, sharing the total portion of load accordingly.

In this paper we consider sample size selection for life tests when the product life follows the two parameter Weibull distribution. Two situations are considered: 1) an acceptance test where the purpose is to determine whether the product under test meets specified or historical life objectives and 2) a routine endurance test where the purpose is to determine a parameter’s value within a sufficiently small interval of uncertainty just to add to a growing body of knowledge and serve as an item of information in future as yet unformulated decision making processes. ...Two situations are considered: 1) an acceptance test where the purpose is to determine whether the product under test meets specified or historical life objectives and 2) a routine endurance test where the purpose is to determine a parameter’s value within a sufficiently small interval of uncertainty just to add to a growing body of knowledge and serve as an item of information in future as yet unformulated decision making processes.

Single-module cycle life of the Horizon® valve-regulated lead-acid battery has been limited principally by the growth of the negative electrode edges. ...Left unchecked in the first-generation Horizon® design, this anode growth contacts the positive electrode in a contiguous cell, shorting the cells, and prematurely ending battery life. In the current Horizon® design, Electrosource has modified the module plenum with an intercellular insulator, which interdicts anode edge growth and moves the end-of-life mechanism to the cathode. ...This modification approximately doubles Horizon® cycle life to greater than 700 cycles (C/ 1 to 80% DOD) and improves robustness of the battery significantly.

Described is an overall life support design for a crew of 100 to 600 persons that encompasses all required life support subsystems, arrangement and construction of Habitat enclosures and protection from the effects of a subsurface environment. ...Regenerative and non-regenerative systems were compared on the basis of life cycle cost. Results of this Life Support System study were much different than those previously conducted for space and submarine application due to the difficulty in rejecting heat. ...This paper presents the requirements and baseline design for a subsurface Life Support System (LSS) to support an underground habitat. The purpose of this effort was to demonstrate/validate the feasibility of building an operational habitat to support survivable and enduring operations of a deeply based ICBM weapon system.

In this reference study, we examine deviations resulting from production and design variations known as” noise factor” which can affect the fatigue life of a parabolic leaf spring. It will be a mistake to evaluate the design roughly with the stress levels on the layer. ...Criteria for the eye forms design and the fatigue behavior of eye forms, the effect on fatigue of leaf spring end form differences, the effect on fatigue of leaf springs with the same rate value designed in different cross-sections, u-bolt fixing force effects and similar topics have been verified with finite element analysis and endurance rig outputs, and the evaluation results are presented in this study.

Commercially available software tools are widely used to assist in conducting life cycle inventory, life cycle assessment (LCA), life cycle impact analysis (LCIA), and design for the environment (DfE) studies. ...On the basis of these scores, the authors chose GaBi version 3.2 as the LCA software package currently best suited for use by experienced life cycle practitioners in conducting environmental life cycle assessments in the automotive industry. ...Five leading software tools, Boustead 4.2, GaBi 3.2, SimaPro 4.0, TEAM 3.0, and Toolkit, currently in use or under consideration by life cycle practitioners, were selected for testing, and a detailed evaluation scheme was used to evaluate the effectiveness of these tools for practical application in automotive life cycle studies.

Life cycle benefits of a fully integrated thermoplastic instrument panel (IP) are compared to a traditional steel lattice construction. ...Design, manufacture, use and end-of-life phases are reviewed and presented in a life cycle management methodology. All components and processes are reviewed in a design for “X” format (i.e., recyclability, assembly, separability, disassembly, etc.) ...This methodology has been found useful to examine complex systems to guide decision makers in optimizing total life cycle costs.

Key features of the inventory modeling and the data collection and analysis methods are included in this paper along with life cycle inventory profiles of aluminum and magnesium alternatives. The life cycle inventory (LCI) was interpreted using a set of environmental metrics and areas needing further research were identified. ...This paper describes a Life Cycle Assessment (LCA) done to evaluate the relative environmental performance of magnesium (Mg) and aluminum (Al) automatic transmission cases.

Cold-lap defects were predicted to eliminate the fatigue crack initiation life but to affect very little the fatigue crack propagation life....Consequently, a specially designed stress-concentration-reducing part termed “stress diffuser” incorporated in the wrap-around welds at the ends of the longitudinal attachments increased the fatigue strength of longitudinal attachments to equal that of transverse attachments but only when cold-laps were eliminated. ...The fatigue life predictions made using the a two-stage Initiation-Propagation (IP) Model were in good agreement with the experimental results.

Determining Li-ion battery life through life modeling is an excellent tool in determining and estimating end-of-life performance. ...Achieving End-of-Life (EOL) can be challenging since it is difficult to achieve both cycle and calendar life during the same test without years of testing. The plan to correlate testing with the model included three (3) distinct temperature ranges, beginning with the four-Season temperature profile, an aggressive profile with temperatures in the 50 to 55°C range, and using a mid-temperature range (40-45°C) as a final comparison test.

This paper gives complete design, development and testing methodology of rubber bush in which pre-compression of rubber is used to enhance rubber bush life. In bogie suspension, axle to torque rod join is critical as it has to transfer lateral and longitudinal load with flexibility. ...In this torque rod to axle joint called as End bush, compressed rubber is used to carry high load with flexibility. Other possible material for bush can be brass bush which able to carry high load however not able to give high flexibility Design and finite element calculations are done to design pre-compression and rubber volume to get desired strength and stiffness to carry required load with flexibility. ...Once this End bush is made, different laboratory testing is carried out to verify durability and stiffness achieved.

Special attention should be given for composite parts which require long service life. If a poor designed composite component shows damage in the service, it becomes more challenging to investigate the cause and determine the repair procedure. ...In the end of the study, very widely discussed issue of using manned aircraft standards in the UAV world is answered with numerical advantages.

One example of an important decision is the way resources are provided to an EVA portable life support system (PLSS) from the life support system. Another example is the impact of including or neglecting waste recovery from a PLSS system on resupply requirements of the life support system. ...Greater benefits are achievable when systems that share common interfaces are optimized as an integrated unit, including taking advantage of possible synergies or removing counterproductive efforts at the mission level. Life support, extravehicular activity (EVA), and habitability are three systems that have significant interfaces with the crew, and thus share many common interfaces with each other. ...Many of these impacts stem from the use of water by the crew and the way that the life support system provides and processes that water. Other resources, especially air-related, can have significant impacts as well.

This is especially true as increased emphasis is placed on extending oil drain intervals and increasing equipment life in the face of greater performance demands through new heavy-duty vehicle designs. End-users ultimately benefit from extended oil drain intervals and increased equipment life. ...End-users ultimately benefit from extended oil drain intervals and increased equipment life. However, the effort to achieve both initiatives will prove successful only through careful development and selection of the proper performance additives and base fluids. ...This paper highlights new automotive gear oil technology specifically developed to balance the opposing needs of extended oil drain intervals and extended equipment life in heavy-duty trucks and buses.

A new technique of heat treatment is developed for the bearings of automotive transmission and chassis to maximize their service life under contaminated and severe environments. This study demonstrates an improvement of the microstructure of bearing steels by applying special heat treatments. ...The endurance test results show that the specimens with new treatment have an excellent fatigue life compared with the conventional bearing samples.

In particular, the paper discusses the impact on the wheel end bearings, which must handle higher GAWRs (gross axle weight ratings) at lower center of gravity heights on electric vehicles. ...This solution focuses on the mid- and large-size SUV market where bearing capacity could be a limiting factor for electric vehicle variants - driving significant wheel end brake corner design changes to accommodate the larger bearings. The paper also looks at the effects of different vehicle parameters between internal combustion engines and electric vehicles, showing the major influencing factor is the GAWR. ...Further, the analysis evaluates the different bearing design load capacities and their performance under a USA duty cycle, including bearing life, torque and stiffness. This analysis shows that an existing design upgraded to meet the electric vehicle GAWR changes the envelope dimensions and increases the weight by 40%, an additional 1.8 kg per wheel end.

Applying the Economic Input-Output Life Cycle Assessment (EIOLCA) method to the question of fielding newly manufactured or remanufactured vehicles provides an illuminating view of the economic and environmental advantages of remanufacturing. ...Expanding and exploiting the entire vehicle life cycle is a profitable and sustainable extension of work to date; such extension calls for remanufacturing to move from vehicle components to the entire vehicle. ...Mainstream remanufacturing will affect entire industries including insurance, licensing, and financing as they incorporate remanufactured vehicles in a new narrative and expanded life cycle. Objective decisions about production, acquisition, and regulation should include considerations for not only the life cycle but extending it as well.

To assess the primary energy and carbon dioxide equivalent (CO2e) implications of vehicle designs utilizing these materials, this study examines the potential life cycle impacts of two lightweight material alternative vehicle designs, i.e., steel and aluminum of a typical passenger vehicle operated today in North America. ...A “cradle-to-cradle” life cycle assessment (LCA) was conducted for these three vehicle material alternatives. LCA methodology for this study included material production, mill semi-fabrication, vehicle use phase operation, and end-of-life recycling. ...Vehicle use phase mass reduction was found to account for over 90% of total vehicle life cycle energy and CO2e emissions. The AIV design achieved mass reduction of 25% (versus baseline) resulting in reductions in total life cycle primary energy consumption by 20% and CO2e emissions by 17%.

This SAE Aerospace Standard (AS) provides the minimum design and performance requirements for individual, inflatable life preservers, divided into six categories: “Adult,” “Adult-Child,” “Child,” “Infant-Small Child,” “Adult-Child-Infant-Small Child,” and “Demonstration.”

According to TMF analysis, cylinder head life which contains the exhaust manifold fulfilled the life cycle target. Temperature and vibration test were done on rig test, good correlation is shown between test and simulation results. ...Moreover, due to shorter length, lighter weight, and less component connections, the exhaust manifold and hot end durability will improve apparently. In this work, an advanced cylinder head with integrated exhaust manifold is adopted in a three-cylinder turbo engine. ...To validate the exhaust manifold and hot end durability, series simulation and test validation work have been done. Firstly, overall steady state and transient temperature simulation was done for global model.