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Full-Text Articles in Mechanical Engineering
Acoustic-Emission Monitoring Of Lap Joint Fatigue Cracks, Siddharth Kannan
Acoustic-Emission Monitoring Of Lap Joint Fatigue Cracks, Siddharth Kannan
Theses and Dissertations
Structural integrity is a pivotal consideration in the field of engineering applications, and understanding the behavior of materials and joints under various loading conditions is critical. This thesis presents a novel approach to detect and analyze fatigue induced cracks in various test specimens using Piezoelectric Wafer Active Sensors. This approach is widely used in Structural Health Monitoring applications involving acoustic emissions that can be captured using PWAS which in turn gives the surface response to applied stresses. The ultimate goal of the research is to identify the length of a fatigue crack originating from lap joints and to develop a …
Study Of Wire Arc Additive Manufacturing With Aluminum Alloy 2219, Sritam Kumar Dash
Study Of Wire Arc Additive Manufacturing With Aluminum Alloy 2219, Sritam Kumar Dash
Theses and Dissertations
This thesis discusses WAAM (wire arc additive manufacturing) technology using TIG (Tungsten Inert Gas) welding method with aluminum 2219 as the substrate and aluminum 2319 as the filler material. The most important characteristic of this method of manufacturing is very little wastage of material as it does not follow the conventional method of manufacturing where material is removed from a bigger block to finally achieve the desired shape. This method uses a layer by layer approach to build the part. Generally, in additive manufacturing, the production time may vary depending on the type of method used. The material deposition rate …
In Silico Analysis Of Advanced Processing Methods For Light-Weight Alloys Powders, Marjan Nezafati
In Silico Analysis Of Advanced Processing Methods For Light-Weight Alloys Powders, Marjan Nezafati
Theses and Dissertations
Light-weight Al and Mg-based metal-matrix nanocomposites (MMNCs) are lauded as one of the most promising structural materials for vehicle, military, and construction applications. These MMNCs are often synthesized using the powder metallurgy (PM) process under liquid nitrogen cryogenic environments to control the grain sizes. It is believed that proper incorporation of the nitrogen species into the bulk lattice during processing could strongly enhance the mechanical properties of MMNCs by forming N-rich dispersoids. In this work, using the density-functional theory (DFT), the adsorption, absorption and diffusion behavior of nitrogen molecule/atoms have been studied and related to t Al and Mg MMNC …
Friction Bit Joining Of Similar Alloy Sheets Of High-Strength Aluminum Alloy 7085, Matthew R. Okazaki
Friction Bit Joining Of Similar Alloy Sheets Of High-Strength Aluminum Alloy 7085, Matthew R. Okazaki
Theses and Dissertations
Friction Bit Joining (FBJ) is a new technology used primarily in joining dissimilar metals. Its primary use has been focused in the automotive industry to provide an alternative joining process to welding. As automotive manufacturing has continually pushed toward using dissimilar materials, new joining processes have been needed to replace traditional welding practices that do not perform well when materials are not weld compatible. FBJ meets these needs perfectly as it provides strength as well as the ability to join materials of almost any kind.The purpose of this research was to explore different applications of the FBJ process. Traditionally FBJ …
Toward A Production Ready Fbj Process For Joining Dissimilar Combinations Of Gadp 1180 Steel And Aa 7085-T76, Kevin Alexander Shirley
Toward A Production Ready Fbj Process For Joining Dissimilar Combinations Of Gadp 1180 Steel And Aa 7085-T76, Kevin Alexander Shirley
Theses and Dissertations
Friction Bit Joining (FBJ) is a new technology that can be used to join dissimilar materials together. This ability makes it a good candidate for creating light weight structures for the automotive industry by combining lightweight materials such as aluminum to stronger materials like advanced high-strength steels. The automotive industry and many other industries have great interest in reducing structure weight to increase fuel efficiency. The purpose of this research is to make FBJ of GADP 1180 to AA 7085-T76 a production ready process by (1) better understanding the effects of process parameters, bit design and tool design on joint …
The Composition And Distribution Of Coal-Ash Deposits Under Reducing And Oxidizing Conditions From A Suite Of Eight Coals, David R. Brunner
The Composition And Distribution Of Coal-Ash Deposits Under Reducing And Oxidizing Conditions From A Suite Of Eight Coals, David R. Brunner
Theses and Dissertations
Eighteen elements, including: carbon, oxygen, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, potassium, calcium, titanium, chromium, manganese, iron, nickel, strontium, and barium were measured using a scanning electron microscope with energy dispersive spectroscopy from deposits. The deposits were collected by burning eight different coals in a 160 kWth, staged, down-fired, swirl-stabilized combustor. Both up-stream and down-stream deposits from an oxidizing region (equivalence ratio 0.86) and reducing region (equivalence ratio 1.15) were collected. Within the deposits, the particle size and morphology were studied. The average particle cross-sectional area from the up-stream deposits ranged from 10 - 75 µm2 and had a …
An Investigation Of Wear-Resistant Coatings On An A390 Die-Cast Aluminum Substrate, D. Adam Mower
An Investigation Of Wear-Resistant Coatings On An A390 Die-Cast Aluminum Substrate, D. Adam Mower
Theses and Dissertations
In this investigation, four coatings were tested for their ability to increase the wear life of A390 aluminum primary clutch sheaves used in continuously variable transmission (CVT). The coatings tested were: hard chrome, electroless nickel metal, hard coat anodizing and composite ceramic coating. The primary clutch sheave material is a die-cast A390 aluminum. A wear test stand was developed to duplicate wear found on CVTs currently in use. The wear was evaluated using four methods. First, the change in shift characteristics of the CVT while running on the wear test stand, second a change in performance using an ATV and …
A Torque Based Power Input Model For Friction Stir Welding, Jefferson W. Pew
A Torque Based Power Input Model For Friction Stir Welding, Jefferson W. Pew
Theses and Dissertations
For decades models have been developed for predicting the size of the weld nugget and heat affected zones in fusion welded structures. The basis for these models is the welding heat input, which is fairly well understood for most arc welding processes. However, this traditional approach is not as straightforward for Friction Stir Welding (FSW). To date, there is no definitive relationship to quantify the heat input for FSW. An important step to establish a heat input model is to identify how FSW process parameters affect weld power. This study details the relationship between FSW process parameters and torque for …
An Investigation Of Improving Wear Of 390 Die-Cast Aluminum Through Hardcoat Anodizing, Michael J. Whiting
An Investigation Of Improving Wear Of 390 Die-Cast Aluminum Through Hardcoat Anodizing, Michael J. Whiting
Theses and Dissertations
The objectives of this research were to investigate the wear that occurs on the surface of a Hardcoat anodized die-cast aluminum surface, which was sliding against a composite rubber belt. This research investigated known wear theories and the results for previous testing to understand the mechanisms that were likely occurring in this application. These theories indicated that the wear occurring may be reduced by changing the hardness of the materials involved. Archard's equation gave tangible evidence of this fact, but related to the base material and not a surface coating. It was hypothesized that Hardcoat anodizing would follow the theory …
Experimental And Numerical Investigation Of Tool Heating During Friction Stir Welding, Joshua L. Covington
Experimental And Numerical Investigation Of Tool Heating During Friction Stir Welding, Joshua L. Covington
Theses and Dissertations
The heat input to the tool has been investigated for friction stir welding (FSW) of aluminum alloy AL 7075-T7351 over a wide range of process operating parameters using a combined experimental/numerical approach. In a statistical Design of Experiments fashion, 54 experimental welds (bead-on-plate) were performed at 27 different parameter combinations. Measured outputs during each of the welds included forces in all three coordinate directions and internal temperature of the rotating tool at three locations near the tool/workpiece interface. The heat input to the tool was also identified for each weld using infrared imaging temperature measurement techniques and the portion of …
Determination Of Effective Strain For The Strainhardening Of Aluminum Subjected To Completely Reversed Strain Combinations, Navin M. Patani
Determination Of Effective Strain For The Strainhardening Of Aluminum Subjected To Completely Reversed Strain Combinations, Navin M. Patani
Theses and Dissertations
It is known that subrecrystallization plastic deformation increases the strength of a metal. The amount of strengthening that may be acquired can be approximated using a strainhardening equation and a simple given strain. The purpose of this thesis was to determine the effective strain for predicting strainhardening for annealed aluminum subjected to completely reversed strain combinations.
The Enrichment Of Hydro-Carbon Fuel By Aluminum Powder In An Open-Hearth Furnace, Rick Sung-Tao Lee
The Enrichment Of Hydro-Carbon Fuel By Aluminum Powder In An Open-Hearth Furnace, Rick Sung-Tao Lee
Theses and Dissertations
The objective of this thesis was to study theoretically the enrichment of hydrocarbon fuels with aluminum powder for an open-hearth furnace.