Engineering Commons^™

A Method Of Assessing Peripheral Stent Abrasiveness Under Cyclic Deformations Experienced During Limb Movement, Courtney Keiser, Kaspars Maleckis, Pauline Struczewska, Majid Jadidi, Jason N. Mactaggart, Alexey Kamenskiy

Department of Mechanical and Materials Engineering: Faculty Publications

Poor outcomes of peripheral arterial disease stenting are often attributed to the inability of stents to accommodate the complex biomechanics of the flexed lower limb. Abrasion damage caused by rubbing of the stent against the artery wall during limb movement plays a significant role in reconstruction failure but has not been characterized. Our goals were to develop a method of assessing the abrasiveness of peripheral nitinol stents and apply it to several commercial devices. Misago, AbsolutePro, Innova, Zilver, SmartControl, SmartFlex, and Supera stents were deployed inside electrospun nanofibrillar tubes with femoropopliteal artery-mimicking mechanical properties and subjected to cyclic axial compression …

Characterization Of In Vivo Damage On Retrieved Total Shoulder Glenoid Liners, Eric Cheatwood, Gerard Simon, Lynn Crosby, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

An attempt was made to retrieve glenoid liners from revision surgery to undertake a retrospective study to measure the resulting in vivo damage. Since the glenoid liners are circumferential, the curvature changes at every point in the component, an “assisting arm” was designed to hold the liner firmly, thus allowing accurate microscopic measurements. We characterized the damage in terms of pitting, embedded debris, complete fracture, abrasion, deformation, delamination, burnishing, grooving, and scratching that took place mutually exclusively. This study of 26 liners showed embedded debris was the most underrated damage mode found on the liners, followed by pitting and abrasion, …

Experimentation Of Abrasion Erosion At High Temperature For Concentrated Solar Power Systems, Tessa Mei-Lin Fong

Boise State University Theses and Dissertations

Concentrated solar power (CSP) is an alternative and sustainable way to produce energy. Studies have shown that running these plants at high temperatures above 700°C can increase the thermal efficiency in heat transfer. Molten salt is usually used as the heat transfer medium but cannot be used due to its low maximum temperature and high freezing point. Running these plants at high temperature brings up the concern of erosion and oxidation. Abrasion erosion occurs through the interaction of particles and material. The goal of this research is to understand material degradation due to abrasion erosion to understand the durability of …

Durability Properties Of Concrete With 100 Percent Coarse Recycled Concrete Aggregates, Tasnia Tarannum Khan

Theses and Dissertations

The supplies of concrete aggregates from natural sources are rapidly reducing. Recycled concrete aggregates (RCA) are produced by crushing the concrete obtained from demolished concrete structures. The purpose of this study is to determine the durability properties of concrete with 100% recycled concrete coarse aggregates and relate the durability of such concrete to the physical, mechanical, and durability properties of RCA and the RCA parent concrete. The correlations of several properties are determined by developing model equations to predict RCA properties. The parent concrete is crushed and graded at two nominal maximum sizes, 1" and 0.75", to determine the RCA …

Lead To Can Abrasion (Ltca) Test, Scott Mangin, Karthik Padmanabhan, Craig Icban

Mechanical Engineering

Pacemakers are medical devices which regulate a person’s heartbeat through electric pulses delivered via an endocardial lead attached to the heart. When a pacemaker is implanted in a patient, there is usually excess length left on the lead. Surgeons will typically wrap the excess lead length around the pacemaker device and close the wound. However, wrapping the lead around the pacemaker outer surface can open the lead to abrasion and cause the lead’s vital electrical insulation to be compromised. This is currently tested using an existing abrasion fixture at Abbott. However, the current tester does not yield consistent data results …

Experimental Study On The Tribo-Chemical Smoothening Process Between Self-Mated Silicon Carbide In A Water-Lubricated Surface-Contact Reciprocating Test, Le Jin, Herbert Scheerer, Georg Andersohn, Matthias Oechsner, Dieter Hellmann

Friction

Silicon carbide (SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment. As well reported in the point-contact tests, this smoothening process works well due to the abundant water as oxidant. After this smoothening process, the tribo-surface is well polished, a closely mated tribo-gap naturally forms, and an ultra-low friction state is built. However, water in the tribo-gap could be insufficient in industrial applications, e.g., the seal gap in mechanical seals. In this study, the tribo-chemical smoothening behavior in such environment was researched. A surface-contact reciprocating test was used to simulate the aqueous environment where water …

Laboratory Study Of The Geotechnical Properties Of Abraded Railway Ballast With Natural And Clay Mix Fouling, Andrew Rohrman

Doctoral Dissertations

With 140,000 miles of active track, railroad freight is the largest method of transporting goods in the United States. An important component of the railroad substructure is the gravel-size aggregate placed below the tracks, called ballast. The ballast is responsible for draining water away from the track, resisting forces from traffic loading, maintaining track position, and reducing loads to acceptable pressures for the subgrade. Ballast is typically selected to be highly angular and uniformly graded, but these characteristics are constantly changing under dynamic traffic loading. As the ballast is loaded, the particles abrade against each other, grinding off stone dust …

Defining An Abrasion Index For Lunar Surface Systems As A Function Of Dust Interaction Modes And Variable Concentration Zones, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street Jr.

Ryan L. Kobrick

Unexpected issues were encountered during the Apollo era of lunar exploration due to detrimental abrasion of materials upon exposure to the fine-grained, irregular shaped dust on the surface of the Moon. For critical design features involving contact with the lunar surface and for astronaut safety concerns, operational concepts and dust tolerance must be considered in the early phases of mission planning. To systematically define material selection criteria, dust interaction can be characterized by two-body or three-body abrasion testing, and sub-categorically by physical interactions of compression, rolling, sliding and bending representing specific applications within the system. Two-body abrasion occurs when a …

Mechanically Assisted Electrochemical Degradation Of Alumina-Tic Composites, Hetal Umesh Maharaja, Guigen Zhang

Publications

Alumina-TiC composite material is a tough ceramic composite with excellent hardness, wear resistance and oxidation resistance in dry and high-temperature conditions. In aqueous conditions, however, it is likely to be electrochemically active facilitating charge transfer processes due to the conductive nature of TiC. For application as an orthopedic biomaterial, it is crucial to assess the electrochemical behavior of this composite, especially under a combined mechanical and electrochemical environment. In this study, we examined the mechanically assisted electrochemical performance of alumina-TiC composite in an aqueous environment. The spontaneous electrochemical response to brushing abrasion was measured. Changes in the magnitude of electrochemical …

Test Method For Predicting Failure Modes In Protective Films, Aubrey Jeanette Decker

Theses and Dissertations

In the business of packaging engineering, a large consumption of time is placed on evaluating new materials to provide cost savings to a company. This evaluation is made by using test methods such as those found in ASTM D4169-16, which helps to simulate shipping and distribution conditions. A key problem is that this test method can take up to multiple months, and sometimes years to complete. The apparatus created in this study allows for a comparison to be made between currently used films and prospective films in approximately ten hours. This allows for a prescreening of new films to be …

Factors Influencing Material Loss During Iron Ore Pellet Handling, Joseph A. Halt

Dissertations, Master's Theses and Master's Reports - Open

Iron ore concentrate pellets have the potential to fracture and abrade during transportation and handling, which produces unwanted fine particulates and dust. Consequently, pellet producers characterize the abrasion resistance of their pellets, using an Abrasion Index (AI), to indicate whether their products will produce unacceptable levels of fines. However, no one has ever investigated whether the AI correlates to pellet dustiness.

During the course of this research, we investigated the relationship between AI and iron ore concentrate pellet dustiness using a wide range of industrial and laboratory pellet samples. The results showed that, in general, AI can be used to …

Impact Abrasion Of Hydraulic Structures Concrete, Yu-Wen Liu, Shi-Wei Cho, Tsao-Hua Hsu

Journal of Marine Science and Technology

Most of the abrasion damage is caused by the action of water-borne particles (silt, sand, gravel, and other solid) impacting and rolling against the concrete surface during hydraulic structure operation. In this paper solid-particle abrasion of concrete containing slag was studied. Experiments included use of river sand abrade of mean diameter ~ 0.6, 1.2, 2.5 and 5 mm, and sand content was 110, 230 and 340 kg per 1 m3 of water, impacting at 30°, 45° and 90° to the concrete surface. And the waterborne sand flow impact test method was used. Test results show that the abrasion rate to …

Derivation Of Correction Terms To The Eikonal Approximations In The Formulation Of Analytical Abrasion-Ablation Model, Santosh Bhatt

Doctoral Dissertations

Analytical models for the quantitative predictions of spectra from the neutrons and light ions produced from the high energy, heavy ion (HZE) reactions are extremely important in assessment of the radiation damage during long duration deep space missions, and for various accelerator applications. The fundamental physics of the secondary particle production and transport from these HZE reactions is described using the abrasion-ablation model. The abrasion part of the model is based on the Glauber multiple scattering theory while the ablation process is based on statistical decay based on an evaporation model. The current formulations for the abrasion process are based …

Defining An Abrasion Index For Lunar Surface Systems As A Function Of Dust Interaction Modes And Variable Concentration Zones, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street Jr.

Publications

Unexpected issues were encountered during the Apollo era of lunar exploration due to detrimental abrasion of materials upon exposure to the fine-grained, irregular shaped dust on the surface of the Moon. For critical design features involving contact with the lunar surface and for astronaut safety concerns, operational concepts and dust tolerance must be considered in the early phases of mission planning. To systematically define material selection criteria, dust interaction can be characterized by two-body or three-body abrasion testing, and sub-categorically by physical interactions of compression, rolling, sliding and bending representing specific applications within the system. Two-body abrasion occurs when a …

Three-Body Abrasion Testing Using Lunar Dust Simulants To Evaluate Surface System Materials, Ryan L. Kobrick, Kenneth G. Budinski, Kenneth W. Street Jr., David M. Klaus

Publications

Numerous unexpected operational issues relating to the abrasive nature of lunar dust, such as scratched visors and spacesuit pressure seal leaks, were encountered during the Apollo missions. To avoid reoccurrence of these unexpected detrimental equipment problems on future missions to the Moon, a series of two- and three-body abrasion tests were developed and conducted in order to begin rigorously characterizing the effect of lunar dust abrasiveness on candidate surface system materials. Two-body scratch tests were initially performed to examine fundamental interactions of a single particle on a flat surface. These simple and robust tests were used to establish standardized measurement …

Slides: Disappearing Roads--An Efd Project: An Exploration Into Low Impact And Efficient Gas Field Drilling, Charles Dolan

Best Practices for Community and Environmental Protection (October 14)

Presenter: Rich Haut, Houston Advanced Research Center (HARC), for Dr. Charles Dolan, University of Wyoming, Environmentally Friendly Drilling Program

25 slides

Study Of High Velocity Attrition Nozzles In A Fluidized Bed, Jennifer Mcmillan, Cedric Briens, Franco Berruti, Edward W. Chan

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

The objective of this study was to test different high velocity attrition nozzles and operating conditions in order to determine the effects of various parameters on the grinding efficiency. Nozzle geometry, as well as gas properties such as speed of sound and density had a significant impact on the grinding efficiency. In addition, a model was developed in order to understand the particle breakage mechanisms during particle attrition. The model showed that the primary attrition mechanism was the splitting of particles rather than their erosion.