Engineering Commons^™

The Effect Of Humeral Short Stem Positioning, Humeral Head Contact, And Head Positioning On Bone Stress Following Total Shoulder Arthroplasty, Amir Tavakoli

Electronic Thesis and Dissertation Repository

Uncemented humeral stems cause stress shielding which result in bone resorption when used in total shoulder arthroplasty (TSA). Shorter length stems show a decrease in stress shielding, however the effect of humeral short stem positioning and humeral head contact and positioning on bone stress is currently not known, hence CT-based tools and Finite Element (FE) methods are used to quantify the effects of the mentioned variables on bone stresses after TSA.

Eight male cadaveric humeri were virtually constructed from computed tomography (CT) data, with a generic short humeral short stem as the implant.

The results of this work show that …

An Investigation On The Influences Of Radial Head Hemiarthroplasty Stem Fixation Techniques On Articular Mechanics, Jakub Szmit

Electronic Thesis and Dissertation Repository

Radial head hemiarthroplasty design has been extensively studied with a focus on utilizing the geometrical characteristics of the native radial dish as a guide of implant placement and design. Although implant design has been studied, optimal radial head implant fixation technique remains unknown. This thesis focused on the effect of stem fit on radiocapitellar contact mechanics, using both finite element and experimental bench-top approaches. Additionally, investigation into the impact of varus/valgus malalignment of the radial head in both the native state and following hemiarthroplasty was conducted. It was found that loose fitting a smooth stem axisymmetric radial head implant through …

Experimental And Numerical Study On Three-Edge Bearing Test For Reinforced Concrete Pipe, Abdul-Aziz Younis

Electronic Thesis and Dissertation Repository

Reinforced Concrete Pipe (RCP) is widely used in storm and wastewater management owing to its resiliency and reliability. The century old Three-Edge Bearing Test (TEBT) is currently used to classify RCP strength. The test relies on the skill and experience of the operator for capturing the occurrence of a 0.3-mm-wide crack using a leaf-gauge, which induces subjectivity and error. Studies have also indicated the TEBT crack bears little structural significance.

This thesis aims at improving the TEBT by replacing the arbitrary crack-width with rational capacity-driven criteria. A wide range of full-scale RCP were instrumented and subjected to the modified TEBT …

Strategies For Ultraprecise Single Point Cutting Of V-Grooves, Delfim A C Joao

Electronic Thesis and Dissertation Repository

V-groove microstructures have found numerous functionalization applications in mechanical, electronic, photonic, biomechanical and optical components. However, despite their wide use, the manufacturing processes associated with their fabrication are limited to axial strategies with a constant depth of cut that do not allow the control of the cutting force and cutting time, and therefore leading to significant micro-burrs as well as an inability to fabricate high aspect ratio grooves. The current thesis addresses this problem with the development of three cutting strategies that make use of a single point cutting process. The study to be detailed herein includes analytical, numerical and …