Engineering Commons^™

Prediction Of Airfoil Stall In Icing Conditions Using Wing Surface Pressures, Erik Pederson

Masters Theses

This thesis presents work on a Normalized Lift Coefficient instrumentation system that predicts airfoil stall in icing conditions. The system uses four surface pressures, measured aft of the ice formation, from which the aircraft's normalized lift coefficient is determined. The pressure port locations were selected such that the calibration algorithm remains nearly constant as the leading edge ice shape and thickness change. Data collected in the Western Michigan University Wind Tunnel is presented for three ice formations varying in both shape and thickness. The ice and no ice conditions were compared and a set of four ports was found that …

Texture And Young’S Modulus Of Nickel/Gamma-Alumina Composites, Abdulaziz Alamr

Masters Theses

To improve Young's modulus of 2024-T3 rolled aluminum specimens, it was electroplated with nickel reinforced with nano-particles of γAl₂O₃. Taguchi method was used to investigate the effect of coating variables, which were current density, coating time, and mixing rate, on the coating thickness. The coatings were tested for crystallographic texture, using pole figures of (200) and (111) for nickel and (400) for γAl₂O₃. Surface topography was measured using WYKO Vertical Interference Microscope. The crystallographic texture of nickel in the coating depended on the coating conditions. A universal testing machine was- used to …

Residual Stress And Wear Resistance Of Composite Coatings Of Nickel/Gamma-Alumina, Khaled Abdulrahman Al-Ogab

Masters Theses

Nickel reinforced with nanoparticles of γ−Al₂O₃ have been successfully codeposited on 2024-T3 cold rolled aluminum alloy by electrodeposition with direct current. The effects of current density, particle concentration in the nickel sulfamate bath, air agitation, and coating time on Ni/γ−Al₂O₃ composite have been investigated. The residual stresses and wear resistance of the Ni/γ−Al₂O₃ composite have been measured using X-ray diffractometer and pin-on-disk techniques respectively. The residual stress and wear resistance behavior of the composite were compared with those of nickel-only deposits. An annealed ground nickel, which was mechanically removed from the …

Small Below-Endurance-Limit Cycle Damage Contributions In Variable Sequence Loading For 2024-T351 Aluminum Alloy, Christopher M. Ngiau

Masters Theses

It is a common practice in industry today to totally discard the presence of small below-endurance/fatigue limit cycles while calculating damage accumulation using the Palmgren-Miner rule. However, it was experimentally found in a number of studies that small cycles with stress amplitudes below the fatigue/endurance limit do in fact contribute significantly to the damage accumulation in all types of materials. There was a need to investigate cases where small cycles would only be present for a certain percentage of the material's life. An experimental study was done on 2024- T351 aluminum alloy. Loading was done in low and high cyclic …

Cfmms – Computerized Facilities Maintenance Management System, Prawit Rotsawatsuk

Masters Theses

Computerized facilities maintenance management systems, previously available only to very large facilities, are now accessible to small and medium-sized maintenance organizations. Advertisements for such products promise reductions in maintenance costs. Where a manual system of maintenance management is currently employed, moderate reductions in maintenance costs and facility downtime are fully possible. Where no formal maintenance management procedures are present, the structure and case of a computerized maintenance system can result in dramatic cost reductions and improvements in facility availability. There are, however, practical limits to the applicability of computerized maintenance systems. The objective of any maintenance program is to minimize …

The Development Of A Fmea Process For Design And Maintenance, Tearesa Lynn Wegscheid

Masters Theses

Failure Modes and Effects Analysis (FMEA) is a systematic way to identify and evaluate potential product and process related failure modes, the associated causes of failures, and the necessary actions to eliminate or reduce the chance of the failure. There are a number of published manuals and books on FMEA. The materials provide a definition of the FMEA form and examples of the Design and Process FMEA. However, there are many inconsistencies throughout the literature. As a result, FMEA is not always value-added.

The thesis is twofold. First, it documents a case study that uses Design FMEA extensively. The case …

Learning Reinforced Concreyte Design Principles Using A Java-Vrml Based Design Studio, Amarneethi Vamadevan

Masters Theses

Dynamics involving reinforced concrete design are the first real engineering course encountered by the undergraduate construction engineering students. Quite often its associated rigorous theories makes it an uninteresting academic hurdle for many below mediocre students. However when the theory is exemplified with multimedia, interaction and visualization techniques, the conceptual understanding is enhanced. The teaching methodology presented in this thesis is based on presenting students with an individualized, interactive and guided learning environment. The main elements of this approach are: a means of assimilating the student's interactive learning knowledge and behavior (user model), representation of the instructor's guidance and assessment knowledge …

A Cmos Chaotic Oscillator, Boonsin Chansilp

Masters Theses

A chaotic oscillator may be used as the basic component of an associative memory (AM). An AM is capable of pattern separation and noise reduction. Chua's circuit is a widely used chaotic oscillator. This circuit consists of a nonlinear resistor, two capacitors, an inductor and a resistor. A discrete implementation of Chua's circuit may be built using operational amplifiers, resistors, diodes, or discrete bipolar transistors. CMOS integrated circuit technology provides the opportunity for a compact implementation which enables construction of systems requiring a large number of oscillators. This thesis develops an integrated circuit design based on previous work performed by …