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A damper is one of the most important elements in a vehicle suspension system. The damper valves are a fully coupled hydraulic system where the suspension fluid flow interacts with the elastic response of the valve structure. The base valve in the hydraulic damper plays a significant role in compression damping force characteristics of a damper, and therefore designing of the base valve is critical for damping force tuning. In this paper, the impact of the base valve design complexity reduction is quantitatively analyzed. The Current base valve design is restrictive which prevents achieving the required compression damping force ranges without a substantial base valve body parts library. A new base valve assembly is suggested with one more degree of freedom via a restrictor plate. Introducing this new element allows reducing the number of base valve designs for damping performance tuning.

This paper presents the “Virtual Failure Mode and Effects Analysis (vFMEA)” system, which is a high-fidelity electrical-failure-simulation platform, and applies it to the software verification of an electric power steering (EPS) system. The vFMEA system enables engineers to dynamically inject a drift fault into a circuit model of the electronic control unit (ECU) of an EPS system, to analyze system-level failure effects, and to verify software-implemented safety mechanisms, which consequently reduces both cost and time of development. The vFMEA system can verify test cases that cannot be verified using an actual ECU and can improve test coverage as well. It consists of a cycle-accurate microcontroller model with mass-production software implemented in binary format, analog and digital circuit models, mechanical models, and a state-triggered fault-injection mechanism.

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.

Experiments were carried out to study the effect of thermal expansion of the tool during Friction Stir Spot Welding (FSSW) of large commercial automotive grade aluminum sheets. The objective of this study was to evaluate the tool “growth” using both experimental and numerical techniques and to see its effect on the weld quality (measured in terms of static strength). Two hundred friction stir spot welds were made over 25 Al sheets (A6022-T4) with a specific time interval between each sheet, thereby trying to simulate the welding conditions/sequence on a production line. An Infrared (IR) camera was used to monitor the temperature gradient on the tool during the welds. In addition, finite element analysis was run to predict the thermal expansion of the tool based on the temperature boundary conditions obtained from the IR camera during the experiment.

A numerical simulation technique was implemented to automatically optimize the plunger velocity to reduce the defects occurring during die-casting by considering the number of free surfaces and potential energy of the molten metal. In pressure die-casting, the most common defect is porosity that is formed by air entrapment in the following two stages - the first is the injection of the molten metal into shot sleeve, and the second is the filling of the molten metal into the cavity. The latter phenomenon has been investigated in detail by various numerical simulation codes, but there is limited information concerning the former. In order to the simulate flow pattern in the shot sleeve, a moving boundary method is incorporated into the conventional filling simulation system. In addition, the plunger speed and the acceleration time for the various pre-filled levels of molten metal in the sleeve are determined by automatic optimization.