Engineering Commons^™

Estimation Of The Fatigue Life Of Additively Manufactured Metallic Components Using Modified Strain Life Parameters Based On Surface Roughness, Peter Grohs

Masters Theses

In this study, a method is developed to estimate the effects of surface roughness on the fatigue life of additively manufactured titanium Ti6Al4V, aluminum 7075–T6, and steel 4340 alloys through modified strain life parameters using finite element analysis (FEA). This method is highly beneficial to the fatigue analysis of as-built additively manufactured metal components, which possess rough surfaces that reduce fatigue life significantly but are challenging to analyze directly using finite element simulation because of complex geometries, i.e., modeling an exact surface profile is arduous.

An effective stress concentration factor, incorporating roughness data, is defined to quantify their effects on …

Finite Element Modeling And Experimental Characterization Of Knot Configuration Effect On The Mechanical Performance Of Surgical Suture, Arz Y. Qwam Alden

Dissertations

Tendon injuries in orthopedic surgery and sports medicine are escalating; hence there is great interest in improving tendon repair. The integrity of tendon repair depends in part on a combination of suture material, suture size and knot configuration. Recent studies have indicated the failure of surgical knots as a failure mode during surgical repair. Further, there is still no consensus on the ideal (best/safest) surgical knot techniques. Also, this failure mode is related to stress concentrations, which cannot be easily established with traditional tensile testing. Most researchers have focused on the measurement and comparison of the gross structural response of …

An Equivalent Plate Model With Orthotropic Material Properties For Adjacent Box-Beam Bridge Superstructure, Timothy Alexander Schnell

Masters Theses

Reflective cracking over the longitudinal joints of adjacent box-beam bridges is a welldocumented and recurrent problem; it is a concern because it leads to poor durability performance. These cracks develop during early stages of bridge construction and have not been eliminate by the design revisions implemented so far.

This study is aimed at developing a rational load demand analysis model for calculating the moment acting at the longitudinal joints in order to determine the impact of post-tensioning on mitigating reflective cracking.

The scope of the study includes calculating moment demand at the shear keys using a rational analysis model based …

Comparative Analysis Of Clavicular Tunnel Confìguration For Coracoclavicular Ligament Reconstruction, Mark Omwansa

Masters Theses

A number of coracoclavicular ligament reconstructions are carried out each year and post surgical fractures of the clavicle have been reported. The primary objective of this research is to develop a comparative metrics that compares clavicular tunnel configurations used in coracoclavicular reconstruction techniques. The goal of this comparison is to reduce post surgical failures due to clavicle fractures. The present analysis compared two techniques { a single 3 mm clavicular tunnel and the other double 6 mm tunnels { experimentally, using Four-point bending testing and Finite Element Analysis (FEA). A unique method, slicing, was used to create an FE clavicle …

Broncoblade: An Open Source Wind Turbine Blade Analysis Tool, Alex R. Quinlan

Masters Theses

This thesis reports the development and validation of BroncoBlade, a horizontal axis wind turbine analysis tool. BroncoBlade prepares finite element models and integrates them with an aeroelastic simulator. Analysis results for the SNL100-00 baseline blade are evaluated against reference results published by Sandia National Laboratories. Variations on the SNL100-00 blade incorporating carbon fiber are compared to the baseline blade.

Statistical And Numerical Integrated Approach For Detecting Onset Of Prefabricated Bridge Component Connection Deterioration, Cem Mansiz

Masters Theses

Bridges are the substantial part of the transportation infrastructure. Most recent report shows that of the 605,086 bridges in the United States, 67,526 (11%) are deemed structurally deficient, and 76,363 (13%) are declared functionally obsolete (FHWA, 2011). Deck is the shelter of a bridge that is subjected to severe loads due to exposure and traffic. Importance of detecting deck deterioration is further highlighted with the introduction of accelerated bridge construction (ABC) where prefabricated components are brought to the site, assembled, and connected using field cast joints. However, durability performance of field cast connections is not encouraging. Hence, continuous monitoring of …