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Lightweight metals such as Al and Mg alloys have been increasingly used for reducing mass in both structural and non-structural applications in transportation industries. Joining these lightweight materials using traditional fusion welding techniques is a critical challenge for achieving optimum mechanical performance, due to degradation of the constituent materials properties during the process. Friction stir welding (FSW), a solid-state joining technique, has emerged as a promising method for joining these lightweight materials. In particular, high joining efficiency has been achieved for FSW of various Al alloys and Mg alloys separately. Recent work on FSW of dissimilar lightweight materials also show encouraging results based on quasi-static shear performance. However, coach-peel performance of such joints has not been sufficiently examined.

Friction stir linear welding (FSLW) is widely used in joining lightweight materials including aluminum alloys and magnesium alloys. However, fatigue life prediction method for FSLW is not well developed yet for vehicle structure applications. This paper is tried to use two different methods for the prediction of fatigue life of FSLW in vehicle structures. FSLW is represented with 2-D shell elements for the structural stress approach and is represented with TIE contact for the maximum principal stress approach in finite element (FE) models. S-N curves were developed from coupon specimen test results for both the approaches. These S-N curves were used to predict fatigue life of FSLW of a front shock tower structure that was constructed by joining AM60 to AZ31 and AM60 to AM30. The fatigue life prediction results were then correlated with test results of the front shock tower structures.

This paper starts with an analysis of design configurations of the drivelines with different power-dividing units (PDUs) of main dump truck manufacturing companies. As it follows from the analysis, improvements of articulated truck energy efficiency and reduction of fuel consumption by optimizing the power distribution to the drive wheels are still open issues. The problem is that a variety of operating and terrain conditions of dump trucks requires different wheel power distributions that cannot be provided by one set of PDUs employed in a truck. The central PDU in the transfer case was identified as the most important PDU among the five PDUs, which plays a crucial role in the power distribution between the front axle and the rear tandem of a 6×6 articulated dump truck. The paper formulates a constraint optimization problem to minimize the tire slippage power losses by optimizing the power distribution between the drive wheels.

Liquid coolants are commonly used as thermal transport media to increase efficiency and flexibility in aerospace vehicle design. The introduction of gas bubbles into the coolant can have negative consequences, including: loss of centrifugal pump prime, irregular sensor readings, and blockage of coolant flow to remote systems. One solution to mitigate these problems is the development of a passive gas removal device, or gas trap, installed in the flight cooling system. In this study, a new hydrophilic, composite membrane has been developed for passage of the coolant fluid and retention of gas bubbles. The trapped bubbles are subsequently vented from the system by a thin, hydrophobic, microporous membrane. The original design for this work employed a homogeneous membrane that was susceptible to fouling and pore plugging.

The Alabama Technology Network, Inc. (ATN) provides technical assistance, management assistance and training that complements workforce and economic development. The ATN center at the University of Alabama in Huntsville (UAH) has focused on lean manufacturing. This paper summarizes the principles of “lean”, presents three phases to implementing lean, and illustrates its application in a training simulation of a setup/changeover reduction. Finally, success stories show how UAH is helping many small and medium size manufacturers improve rapidly using lean techniques.

The problem of supplying JIT assembly workstations from a central depot with a goal of minimizing inventory and vehicle requirements is the focus of this paper. To minimize work-in-process inventory, the quantity of component parts delivered to each workstation must be just enough to satisfy production until the next delivery of components. To minimize vehicle requirements, there should be no vehicle idle time. The problem is modeled as a vehicle routing problem with a nonlinear capacity constraint. A heuristic solution procedure is outlined and a relaxed formulation is given to provide a lower bound on the number of vehicles required.

A nominal 520 kW (thermal) air-conditioning system based on the seasonal storage of cold water in an aquifer has cooled a University of Alabama building since 1983. During cold weather, ambient, 18° C water is pumped from warm supply wells, chilled to about 6° C in a cooling tower, and reinjected into separate cold storage wells. In warm weather, water is withdrawn from the cold wells and pumped through building heat exchangers for air conditioning. Presented here are results of 6 years of study [sponsored by the U.S. Department of Energy through Pacific Northwest Laboratory] of the first successful U.S. application of this technology. This system yields high energy efficiency, with measured annual average COP of about 5 (SEER = 17 Btu/Wh), and energy recovery efficiency ranging from 40 to 85%, shifts utility loads from summer to winter, and no chlorofluorocarbon (CFC) release.