Applied Mechanics Commons^™

Implementation Of Magnetic Resonance Elastography For The Investigation Of Traumatic Brain Injuries, Thomas Boulet

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Magnetic resonance elastography (MRE) is a potentially transformative imaging modality allowing local and non-invasive measurement of biological tissue mechanical properties. It uses a specific phase contrast MR pulse sequence to measure induced vibratory motion in soft material, from which material properties can be estimated. Compared to other imaging techniques, MRE is able to detect tissue pathology at early stages by quantifying the changes in tissue stiffness associated with diseases. In an effort to develop the technique and improve its capabilities, two inversion algorithms were written to evaluate viscoelastic properties from the measured displacements fields. The first one was based on …

Stochastic Optimal Control In Nonlinear Systems, Celestin Nkundineza

Celestin Nkundineza

Stochastic control is an important area of research in engineering systems that undergo disturbances. Controlling individual states in such systems is critical. The present investigation is concerned with the application of the stochastic optimal control strategy developed by To (2010) and its implementation as well as providing computed results of linear and nonlinear systems under stationary and nonstationary random excitations. In the strategy the feedback matrix is designed based on the achievement of the objectives for individual states in the system through the application of the Lyapunov equation for the system. Each diagonal element in the gain or associated gain …

Static Balancing Of The Cal Poly Wind Turbine Rotor, Derek Simon

Master's Theses

The balancing of a wind turbine rotor is a crucial step affecting the machine’s performance, reliability, and safety, as it directly impacts the dynamic loads on the entire structure.

A rotor can be balanced either statically or dynamically. A method of rotor balancing was developed that achieves both the simplicity of static balancing and the accuracy of dynamic balancing. This method is best suited, but not limited, to hollow composite blades of any size. The method starts by quantifying the mass and center of gravity of each blade. A dynamic calculation is performed to determine the theoretical shaking force on …

Application Of Higher Order Hamiltonian Approach To Nonlinear Vibrating Systems, Hassan Askari

No abstract provided.

Human Powered Helicopter: Rotor Structure, Joseph Ram, Juan Carlos Olvera

Mechanical Engineering

The following report encompasses the Human Powered Helicopter Rotor Team’s conceptual models and ideas based on research and modeling analysis. The following gives an overview of material researched, concept generation, analyzation, manufacturing, and testing for a rotor structure to be installed in a Human Powered Helicopter.

Supermileage Chassis Dynamometer, Jose Garcia, Steve Janning, Timothy Lui, Kyla Purvis

Mechanical Engineering

This report describes the final design and analysis of a hydraulic chassis dynamometer as a testing tool for California Polytechnic State University, San Luis Obispo Supermileage Vehicle Team (CPSMV). Literature review was conducted to understand the various types of chassis dynamometers on the market as of the year 2011. After rigorous research, it was determined that a hydraulic system was the best system for a chassis dynamometer in terms of functionality, performance, and cost. Critical study of hydraulics, dynamometers, and data acquisition systems (DAQ) was followed by a complete design of a hydraulic system. The chassis dynamometer proposed in this …

California Olive Ranch Hedger, Tyler Enos, Seth Abbott, David Gamba

Mechanical Engineering

The purpose of this project is to evaluate the problems of the current KCI (Kingsburg Cultivator Incorporated) olive tree hedger in use at California Olive Ranch (COR) in Artois, CA, and then correct these problems which should yield a better performing, more efficient, and reliable machine. These problems include: the hydraulic oil temperature getting too high, the saw blades not having enough horsepower, and poor cutting performance due to operator error as well as terrain variations.

Analytical Approximate Solutions For The Generalized Nonlinear Oscillator, Hassan Askari

No abstract provided.

A Relationship Between Three Analytical Approaches To Nonlinear Problems, Hassan Askari

No abstract provided.

Semi-Active Damping For An Intelligent Adaptive Ankle Prosthesis, Andrew K. Lapre

Masters Theses 1911 - February 2014

Modern lower limb prostheses are devices that replace missing limbs, making it possible for lower limb amputees to walk again. Most commercially available prosthetic limbs lack intelligence and passive adaptive capabilities, and none available can adapt on a step by step basis. Often, amputees experience a loss of terrain adaptability as well as stability, leaving the amputee with a severely altered gait. This work is focused on the development of a semi-active damping system for use in intelligent terrain adaptive ankle prostheses. The system designed consists of an optimized hydraulic cylinder with an electronic servo valve which throttles the hydraulic …