Applied Mechanics and Materials Vol. 165

Abstract: Proportional Integral Derivative and clipped-optimal control strategy controllers are studied to control the response of Quarter-car suspension profile. A Semi-active device is used for this purpose because it carries valuable result which maintains the reliability of passive control methods and includes the advantage of the adjustable parameter characteristics of active systems. Semi-active devices like Magnetorheological fluids dampers are very effective to control vibration, which use MR fluids to produce controllable damping force and provide both the reliability of passive systems and the facility of active control systems with small power supply. The quarter car model is used here can be described as a nonlinear two degrees of freedom system which is subject to excitation from different road profile. For the best possible reduction of vibration in suspension systems, various Magnetorheological damper models are studied which Bouc-wen model, Neuro-fuzzy model and Bingham model. The performances of these models are evaluated to select a best model. The quarter-car model is executed using step input with two most common and effective control algorithm in vehicle suspension control which are linear quadratic regulator control, and Proportional Integral Derivative control algorithm. The main objective of this study is to evaluate performances of these control algorithms.

Abstract: This paper reports the early results of the evaluation of driver's pre-driving skill on a driving simulator using the Intelligent Dynamic Event Analyzer approach. The IDEA Evaluator module, developed as an out-of-process Component Object Model ActiveX-Exe, is integrated into the ASIS^TM driving simulator to monitor drivers action during pre-driving activities. Fundamental actions detected from ASISTM simulator are fed to the Intelligent Dynamic Event Analyzer evaluator module and the result (Correct / Incorrect) is returned back to ASIS^TM. The integrated system was observed to be able to successfully evaluate the driver activities. The whole process is executed online utilizing ASIS^TM driving simulator module.

Abstract: This paper describes the design of a Special Purpose Off Road Vehicle which was developed as the main body for an Unmanned Ground Vehicle. The stringent requirement for off-road capabilities and the need to incorporate a plethora of vision based sensing mechanism was the main design criteria that were fulfilled by the Special Purpose Off Road Vehicle. The Special Purpose Off Road Vehicle is incorporated with a host of actuators, instrumentation and drive circuits, Data Acquisition System and remote communication and control module. The Special Purpose Off Road Vehicle is also equipped with an onboard 2 GHZ Pentium Core 2 Duo Processor Class PC that serves as the main controller when it is operated in the UGV mode. The final prototype unit of the Special Purpose Off Road Vehicle was successfully designed, developed and fabricated according to the set requirement and is used as a research prototype unit at Science and Technology Research Institute for Defence, Ministry Of Defence, Malaysia.

Abstract: This paper presents the quantification of Field of View of external Rear View Mirror in automobiles. The decision based on available Field of View and the blind zone for lane changing is one of the major factors in road accident. This study presents a preliminary study of quantifying field of view of rear view mirror in automotive vehicles. A simple method of estimating the Field of View is shown and also a passive method of increasing the Field of View is discussed. The proposed method helps the designers and road users to choose the mirror of right size to provide extra field of view beyond the regulatory requirements.

Abstract: The finite element method is used to construct the sequential processing model of the package. The model is used to simulate the warpage and interfacial stresses of FBGA (Fine-pitch Ball Grid Array) package due to the coefficient of thermal expansion mismatch between layered materials of package during assembly processes. The processing model uses the function of element birth and death to simulate the processing step of package model, considering the sequentially accumulated warpage and stresses during the processing steps. The induced package stresses can cause the delamination between die/die attach interface. In order to verify the simulation results, the simulated package warpage of a standard package is compared with the measurement of package warpage of the package. In this study, the effect of solder balls layout on the warpage and interfacial stresses at die/die attach interface is discussed by simulation results.

Abstract: Composite slab construction using permanent cold-formed steel decking has become one of the most economical and industrialized forms of flooring systems in modern building structures. Structural performance of the composite slab is affected directly by the horizontal shear bond phenomenon at steel-concrete interface layer. This study utilizes 3D nonlinear finite element quasi-static analysis technique to analyze the shear bond damage and fracture mechanics of the composite slabs. Fracture by opening and sliding modes of the plain concrete over the corrugated steel decking had been modeled with concrete damaged plasticity model available in ABAQUS/Explicit module. The horizontal shear bond was simulated with cohesive element. Cohesive fracture properties such as fracture energy and initiation stress were derived from horizontal shear bond stress versus end slip curves. These curves were extracted from bending tests of narrow width composite slab specimens. Results of the numerical analyses match the experimental results accurately. This study demonstrated that the proposed finite element model and analysis procedure can predict the behavior of composite slabs accurately. The procedure can be used as a cheaper alternative to experimental work for investigating the ultimate strength and actual fracture and damage behavior of steel-concrete composite slab systems.

Abstract: The potential use of MFC actuator as a tool for reducing low velocity impact induced delamination has been investigated using LS-DYNA explicit finite element code. An induced strain piezoelectric actuation model was implemented into LS-DYNA through its user defined material subroutine to simulate the piezoelectric effects while a cohesive based damage model was used to predict delamination. The numerical study confirmed that delamination could be reduced but the MFC required very high actuation voltages even in the case of very low energy impact which is not practically achievable with the existing actuator. Assuming powerful actuators are not something impossible in near future, this study provide useful information for advancing composite impact investigation using piezoelectric actuator as an integrated tool for improving its impact tolerance.