Engineering Commons^™

Pitting Corrosion And Corrosion Fatigue Crack Growth Behavior Of Oil-Grade Alloy 718 In Sodium Chloride Solution, Ting Chen

Graduate Theses, Dissertations, and Problem Reports

Oil-grade nickel-base alloy 718 has been recently used in the oil and gas industry for downhole drilling components especially for the parts of the bottom hole assembly (BHA) due to its superior mechanical properties, good corrosion resistance, non-magnetic properties and ability to be heat treated to various strength levels. As the modern oil and gas industry explored into coastal and marine locations, deeper and deeper wells have been drilled with high pressure high temperature, making the demand for increased strength and good toughness super critical for alloys used in ultra-deep wells drilling. Moreover, the existence of high concentrations of chloride …

Fault-Tolerant Trajectory Tracking Of Unmanned Aerial Vehicles Using Immunity-Based Model Reference Adaptive Control, Brenton K. Wilburn

Graduate Theses, Dissertations, and Problem Reports

This dissertation presents the design, development, and simulation testing of an adaptive trajectory tracking algorithm capable of compensating for various aircraft subsystem failures and upset conditions. A comprehensive adaptive control framework, here within referred to as the immune model reference adaptive control (IMRAC) algorithm, is developed by synergistically merging core concepts from the biologically- inspired artificial immune system (AIS) paradigm with more traditional optimal and adaptive control techniques. In particular, a model reference adaptive control (MRAC) algorithm is enhanced with the detection and learning capabilities of a novel, artificial neural network augmented AIS scheme. With the given modifications, the MRAC …

Electroplating Of Cr-Ni Alloy And Ni-Cr/Ni Multilayer Coatings, Liaowang Liu

Graduate Theses, Dissertations, and Problem Reports

The major interests of developing Ni-Cr alloy plating lie in the possible formation of a passive film by chromium and its good chemical and mechanical properties. And nano scale multilayer coatings exhibit improved properties due to nano scale effects (e.g.: high hardness and strength) and they combine and enhance different properties from individual components. Thus, electroplating of Ni-Cr multilayer coatings could have high potential for numerous engineering applications. Electroplating in aqueous and in organic solution by direct current were studied for Ni-Cr alloy coatings, and Ni-Cr multilayer coatings were prepared by pulse current electroplating in single bath.

Traditionally, chromium or …