Applied Mechanics Commons^™

Human-Robot Interaction For Assistive Robotics, Jiawei Li

Dissertations

This dissertation presents an in-depth study of human-robot interaction (HRI) withapplication to assistive robotics. In various studies, dexterous in-hand manipulation is included, assistive robots for Sit-To-stand (STS) assistance along with the human intention estimation. In Chapter 1, the background and issues of HRI are explicitly discussed. In Chapter 2, the literature review introduces the recent state-of-the-art research on HRI, such as physical Human-Robot Interaction (HRI), robot STS assistance, dexterous in hand manipulation and human intention estimation. In Chapter 3, various models and control algorithms are described in detail. Chapter 4 introduces the research equipment. Chapter 5 presents innovative theories and …

Control Of Mr Damper Using Anfis And Pid Controller For Optimum Vehicle Ride Comfort, Mohammad Faisal Yakhni, Mohamad Ali, Mohamed El-Gohary

BAU Journal - Science and Technology

Suspension system design is an important challenging duty that facing car manufacturers, so the challenge has become to design the best system in terms of providing ride comfort and handling ability under all driving situations. The goal of this paper is to provide assistance in enhancing the effectiveness of the suspension system. A full car model with eight Degrees Of Freedom (DOF) was developed using MATLAB/Simulink. Validation of the Simulink model was obtained. The model was assumed to travel over a speed hump that has a half sine wave shape and amplitude that changing from 0.01 to 0.2 m. The …

Numerical Simulation Of Nonlinear Vibrations Of Discrete Mass With Harmonic Force Perturbation, M. Yusupov, B. A. Akhmedov, Olga Karpova

Acta of Turin Polytechnic University in Tashkent

The problem of vibration of a single-mass system under the force excitation of vibration associated with a fixed base by a weightless nonlinear viscoelastic spring is considered. To take into account the rheological properties of the spring material, the Boltzmann-Volterra principle was used. Mathematical models of the problem under consideration are obtained, which are described by integro-differential equations. A solution method based on the use of quadrature formulas has been developed and a computer program has been compiled on its basis, the results obtained are presented in the form of graphs. The influence of nonlinear and rheological properties of a …

Dynamic Neuromechanical Sets For Locomotion, Aravind Sundararajan

Doctoral Dissertations

Most biological systems employ multiple redundant actuators, which is a complicated problem of controls and analysis. Unless assumptions about how the brain and body work together, and assumptions about how the body prioritizes tasks are applied, it is not possible to find the actuator controls. The purpose of this research is to develop computational tools for the analysis of arbitrary musculoskeletal models that employ redundant actuators. Instead of relying primarily on optimization frameworks and numerical methods or task prioritization schemes used typically in biomechanics to find a singular solution for actuator controls, tools for feasible sets analysis are instead developed …

Processing-Structure-Performance Relationships In Fused Filament Fabricated Fiber Reinforced Abs For Material Qualification, William Howard Ferrell

Doctoral Dissertations

This dissertation uses the processing-structure-performance relationships to elucidate future needs in qualification of materials manufactured by fused filament fabrication and also introduces a previously unused testing method for the determination of fracture toughness in these materials. Fused filament fabrication (FFF) is an additive manufacturing technique that utilizes the layering of deposited molten plastic in two dimensional shapes to create three dimensional objects. This technique has gained traction over the past two decades as a disruptive manufacturing technology that promises many benefits. In order for FFF to truly be a staple in manufacturing spaces across the world for the production of …

Numerical Simulations Of Directed Self-Assembly Methods In Di-Block Copolymer Films For Efficient Manufacturing Of Nanoscale Patterns With Long-Range Order, Joseph Hill

Graduate Theses and Dissertations

Directed self-assembly (DSA) of block copolymers (BCPs) has been shown as a viable method to achieve bulk fabrication of surface patterns with feature sizes smaller than those available through traditional photolithography. Under appropriate thermodynamic conditions, BCPs will self-assemble into ordered micro-domain morphologies, a desirable feature for many applications. One of the primary interests in this field of research is the application of thin-film BCPs to existing photolithography techniques. This “bottom-up” approach utilizes the self-assembled BCP nanostructures as a sacrificial templating layer in the lithographic process.

While self-assembly occurs spontaneously, extending orientational uniformity over centimeter-length scales remains a critical challenge. A …

Mechanical And Frictional Behavior Of Textured And Non-Textured Surfaces, Raghuram R. Santhapuram

Graduate Theses and Dissertations

Tribology is the study of surfaces where two objects are sliding against another. Significant energy is lost due to friction between the sliding surfaces. Therefore, developing or designing surfaces to minimize friction is critical for the durability and reliability of the mechanical components. Several researchers have identified that surface texturing at the nanoscale (nanotexture) would reduce the friction between the contacting surfaces. The nanotextured surfaces have several applications in microelectromechanical systems and nanoelectromechanical systems. This dissertation employs molecular dynamics simulations to investigate the frictional and mechanical response of nanotextured aluminum (Al) and Al/amorphous silicon (a-Si) composite surfaces.

This study determines …

Adhesion And Deformation Mechanisms Of Polydopamine And Polytetrafluoroethylene: A Multiscale Computational Study, Matthew Brownell

Graduate Theses and Dissertations

Polydopamine (PDA) has been shown to bond via covalent bonding, van der Waals forces, and hydrogen bonding and is known to adhere strongly to almost any material. The application of PDA between a substrate and a PTFE surface coating has resulted in low friction and a greatly reduced wear rate. Previous research probing the capabilities and limitations of PDA/PTFE films have studied the wear and mechanical properties of the film, but the overall adhesive and deformation mechanisms remain unclear.

In this research, we investigate the tribological properties of PDA and PTFE molecules and composites from the atomic to the microscale …

Design, Fabrication, And Reliability Effects Of Additively Manufactured First Level Compliant Interconnects For Microelectronics Application, Tumininu David Olatunji

Graduate Theses and Dissertations

Semiconductor packaging and development is greatly dependent on the magnitude of interconnect and on-chip stress that ultimately limits the reliability of electronic components. Thermomechanical related strains occur because of the coefficient of thermal expansion mismatch from different conjoined materials being assembled to manufacture a device. To curb the effect of thermal expansion mismatch between conjoined parts, studies have been done in integrating compliant structures between dies, solder balls, and substrates. Initial studies have enabled the design and manufacturing of these structures using a photolithography approach which involves a high number of fabrication steps depending on the complexity of the structures …

Practical Adhesion Measurements In Organic Coatings; Advancing Understanding And Mechanical Methods Development, Diana Gottschalk

Dissertations

“Adhesion” can be considered either a mechanical or chemical phenomenon. The mechanical interpretation describes the difficulty of separating surfaces and is useful for quantifying performance within applications that depend on bulk and interfacial properties. Chemical adhesion describes interfacial resistance to chemical attack and does not depend on bulk properties. Predicting chemical failure through mechanical measurement is confounded by the influence of bulk properties. However, the prospect is attractive because of the robust tolerance for sample geometries, allowing experiments to resemble an end-use system. The present work's primary goal was to elevate mechanical methods to provide a detailed interfacial characterization of …

The Varied Thermal Response Of Magnetic Iron-Oxide Nanoparticles During Induction Heating In Liquid And Solid-Liquid Phase Change Mediums, Joshua Tompkins

Graduate Theses and Dissertations

This study investigates the induction heating response of uncapped iron oxide nanoparticles sonically dispersed as a nanofluid and mechanically distributed in solid phase change materials. The nanoparticles examined have a mean diameter of 14.42 nm and are magnetically heated in an alternating magnetic field at an amplitude of 72.6 kA/m at frequencies of 217, 303, and 397 kHz. Nanoparticle characterization was undertaken through transition electron microscopy, x-ray diffraction, and dynamic light scattering when in suspension. Carrier fluids were characterized through viscosity, heat capacity, and density measurements which were used in the calorimetric calculation of the specific absorption rate (SAR) of …

Large Displacement J-Integral Double Cantilever Beam (Dcb) Test Method For Mode I Fracture Toughness, Joshua Gunderson

Boise State University Theses and Dissertations

The J-integral is used to develop an alternative double cantilever beam (DCB) test method for the Mode I fracture toughness suitable for both small and large displacements. The current focus is the experimental determination of the Mode I interlaminar fracture toughness of composite materials, but the method is generally applicable to other similar tests and material systems, such as to the Mode I fracture toughness of adhesives. A series of five identical specimens are tested to compare the linear-elastic fracture mechanics method recommended by ASTM, which makes use of linear beam theory with root rotation, large displacement, and end …

Final Design Review Report: The Underdogs, Parker Johnson, Jack Montgomery, Katherine Thomas

Mechanical Engineering

Aspen is a three-legged dog with mobility issues from Berkeley, California. She was hit by a car and her rear left leg was amputated at the hip. Robin Swanson, Aspen's owner, and her friend, Audrey Beil, are the sponsors for this project. Jack Montgomery, Katherine Thomas, and Parker Johnson, “The Underdogs”, are tasked with helping Aspen regain some of her mobility and the ability to go on walks. Research was done into the problem by talking with the sponsors and looking into existing products, designs, and patents. This document, the Final Design Review Report, outlines the background information, problem specification, …

2 Degree Of Freedom Robotic Leg, Oded Tzori, Henry Terrell, Adan Martinez

Mechanical Engineering

Professor Xing, an assistant professor at Cal Poly, proposed the 2 DOF Robotic Leg project for this quarter’s senior project class. The project is to build a robotic leg attached at the hip to a stand, which will be used as a teaching tool and eventually help develop Cal Poly’s very own robotic quadruped. Since this project has multiple uses after its completion, there are multiple customers that it must perform well for: the Cal Poly Mechanical Engineering (ME) Department, the ME Lab instructors, and the students. The Scope of Work (Sections 2 & 3) is composed of 2 main …

On The Stress Concentration At Sharp V-Notches Under Tension, Trent Mattieu Andrus

LSU Master's Theses

Accurately determining stresses at re-entrant corners using finite element analysis (FEA) is challenging due to the high stresses produced at the corner. Indeed, FEA is unable to obtain quantitatively accurate peak stresses at mathematically sharp re-entrant corners with traditional boundary conditions because these stresses are singular. Imposing a local corner radius by rounding the sharp corner to remove the singular result is an appropriate technique for large radii, but as the corner radius tends to zero and the notch is close to being sharp, we expect there are radii that yield quantitatively inaccurate results with traditional FEA. We seek to …

Dynamic Analysis Of Viscoelastic Circular Diaphragm Of A Mems Capacitive Pressure Sensor Using Modified Differential Transformation Method, Dr Olurotimi A. Adeleye, Muritala Yusuf, Oluwaseyi .. Balogun

Karbala International Journal of Modern Science

In this paper, a dynamic analysis of the viscoelastic circular diaphragm of a Micro-Electro-Mechanical System (MEMS) capacitive pressure sensor using the Modified Differential Transformation Method (MDTM) is presented. The MEMS technology has been increasingly used to fabricate sensors and actuators and the MEMS capacitive pressure sensor is emerging in many high-performance applications. The deflection of these sensors diaphragm (plate) depends largely on the material of the diaphragm. In this study, a circular diaphragm of viscoelastic material is modeled using the classical plate theory. The governing differential equation is solved using Modified Differential Transformation Method (MDTM) and the result is validated …

Homogenization Of Composite And Cellular Materials Incorporating Microstructure And Surface Energy Effects, Ahmad Gad

Mechanical Engineering Research Theses and Dissertations

In the last few decades, the popularity of composite and cellular materials has rapidly increased through their widespread applications in multiple engineering fields including aerospace, automotive, civil and biomedical. However, to a large extent, the success of their practical applications depends on our ability to predict their mechanical behavior by using high-fidelity mechanics models.

Micromechanical modeling of composite and cellular materials is a challenging task due to the heterogeneous nature of such materials and the interactions among various constituent phases at the microscopic level, which result in non-homogeneous deformation, strain and stress fields. Therefore, it is necessary to develop simple …

Cracking And Earing Phenomenon In Deep-Drawn Stainless Steel Alloys: Role Of Transformation Kinetics, Microstructure, And Texture, Peijun Hou

Doctoral Dissertations

The enhancement of formability of advanced high-strength TRIP-assisted steel alloys is a challenging assignment for industrial application due to the cracking phenomenon. The critical factor governing the cracking behavior is residual-stress concentration resulting from the inhomogeneous plastic deformation and microstructural evolution during the forming processes. Martensitic phase transformation kinetics, constituent phases, and crystallographic texture in TRIP-assisted steel alloys are correlated to the microstructure evolution, resulting in phase-specific stress concentration. In the current study, we are aiming at understanding the fundamental mechanisms responsible for the cracking phenomenon and thus improving the formability of TRIP-assisted steel alloys. Four stainless steel (SS) alloys …

Methods For Mass Data Acquisition Of Whiskey Webs., Adam D. Carrithers

Electronic Theses and Dissertations

Whiskey webs are a recently discovered phenomenon in which the monolayer collapse during evaporation of diluted American whiskey results in self-assembled, web-like structures. It was found that the pattern of weblike structures were unique between different American whiskey products. It is desirable to use these unique patterns as a “fingerprint” which can be used to identify whiskeys, their chemical constituents, and perhaps even counterfeits. In pursuit of identifying whiskey products based on their web pattern, it is necessary to have a large database of samples imaged for each product. The device discussed herein is the realization of an apparatus capable …

Dynamic Analysis And Fabrication Of A Bi-Stable Structure Designed For Mems Energy Harvesting Applications., Masoud Derakhshani

Electronic Theses and Dissertations

Thanks to the rapid growth in demand for power in remote locations, scientists’ attention has been drawn to vibration energy harvesting as an alternative to batteries. Over the past ten years, the energy harvesting community has focused on bistable structures as a means of broadening the working frequency range and, by extension, the effective efficiency of vibration-based power scavenging systems. In the current study, a new method is implemented to statically and dynamically analyze a bistable buckled, multi-component coupled structure designed specifically for low-frequency vibration energy harvesting systems in both macro and MEMS-scale sizes. Furthermore, several micro-fabrication steps using advanced …

Spring Loaded Camming Device, Jared S. Christner, Kaitlin O. Deherrera, Ryan W. Edwards, John S. Hickey

Mechanical Engineering

Spring loaded camming devices or “cams” are used in traditional rock climbing as a means of active fall protection. Climbers place cams in cracks and fissures in the rock wall. The cam’s lobes press against the walls, locking it in place, anchoring the climber in case of a fall. Currently, there is a lack of large cams on the market. Only two small companies produce cams that are usable in cracks 6.5 inches wide and larger, however their designs are either too heavy and/or lack features to be comfortable. We are a group of mechanical engineering students at Cal Poly …

Automated Drone Calibration System, Jackie Kelly Jong-Mee Paik, Zach Nathan Richter, Tyler Wilson Van Den Berg, Ryan Alexander Zhan, Matthew Ward Carlson

Mechanical Engineering

The final design review of the Inspired Flight Calibration Team senior project will detail the process used to complete a verification prototype of a drone calibration device and discuss lessons learned and suggestions for improving this device. Going from brainstorming and conceptual prototyping all the way through verification prototyping and testing, we were able to design a gyroscopic device that met Inspired Flight’s needs for the flight sensor calibration of their drones. The mechanical design involved comprehensive CAD models and hands-on manufacturing. The mechatronics side of the project worked heavily with electrical wiring and writing custom software to communicate and …

Safran Seat Attachment System, Craig John Kimball, Tyler Bragg, Lynette Cox

Mechanical Engineering

This final design review (FDR) document outlines the senior design project being carried out by a team of mechanical engineering undergraduate students attending California Polytechnic State University, San Luis Obispo for Safran Seats in Santa Maria, CA. The project originally was to design, build, and test a universal attachment to secure a widebody business class seat to seven aircraft models with different seat track geometry. The goal was to design, document, and create a finished product that fits design, weight, and manufacturing requirements, as well as passes static 9G FWD testing. Structural analysis, manufacturing analysis, FEA, and CAD assemblies will …

Design Of Structural Stand For High-Precision Optics Microscopy, Sara T. Novell

Master's Theses

Lawrence Livermore National Lab (LLNL) is home to the National Ignition Facility (NIF), the world’s largest and most energetic laser. Each of the 192 beamlines contains dozens of large optics, which require offline damage inspection using large, raster-scanning microscopes. The primary microscope used to measure and characterize the optical damage sites has a precision level of 1 µm. Mounted in a class 100 clean room with a raised tile floor, the microscope is supported by a steel stand that structurally connects the microscope to the concrete ground. Due to ambient vibrations experienced in the system, the microscope is only able …

Smartphone-Tape Method For Calculating Body Segment Inertial Parameters For Analysis Of Pitching Arm Kinetics, Jay Sterner

Master's Theses

The objectives of this study were to (1) develop a non-invasive method (referred to as Smart Photo-Tape) to calculate participant-specific upper arm, forearm, and hand segment inertial properties (SIPs) (e.g. mass, center of mass, and radii of gyration) and (2) use those Smart Photo-Tape properties in inverse dynamics (ID) analyses to calculate injury-related pitching arm kinetics. Five 20- to 23- year-old baseball pitchers were photographed holding a baseball and analyzed using the Smart Photo-Tape method to obtain 3-D inertial properties for their upper arm, forearm, and hand. The upper arm and forearm segments were modelled as stacked elliptic cylinders and …

The Development Of All Solid-State Optical Cryo-Cooler, Junwei Meng

Optical Science and Engineering ETDs

This dissertation describes the development of an all solid-state optical cryo-cooler. Crystals of 10% wt. ytterbium-doped yttrium lithium fluoride (Yb³⁺:YLF) are used to cool an infrared HgCdTe sensor payload to an absolute temperature below 135 K, equivalent to delta T equal 138 K below ambient. This record level of cooling is accomplished with a single stage, in a completely vibration-free environment, with a corresponding cooling power of 190 mW. This milestone is made possible by the design and fabrication of an undoped YLF thermal link that efficiently shields the payload with a non-right angle kink from intense anti-Stokes …

In-Service Performance Evaluation Of Concrete Sloped End Treatments In Iowa, Jessica Lingenfelter

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Sloped end treatments were historically developed as low-cost, low-maintenance end treatments for rigid features like concrete barriers and bridge rails. Crash testing indicated that sloped end treatments are associated with significant instability for impacting vehicles. However, the in-service performance of these features has not been evaluated. An in-service performance evaluation (ISPE) was performed to evaluate vehicle crashes with sloped end treatments in Iowa between 2008 and 2017. Researchers generated a geographic inventory of sloped end treatment locations, reviewed crash narratives and scene diagrams for crashes near these sloped end treatments, and calculated an estimated crash rate and crash cost for …

Golf Swing Trainer Using Wii Balance Board, Brooks M. Leftwich, Nicholas Hassler, Clark A. Hall, Sam Gates, Thomas B. Vickery, Alec Rinehart, Zakkary B A Compton, Ryan A. Singley

Chancellor’s Honors Program Projects

No abstract provided.

Sae Baja Drivetrain, Troy Von Gillern, Kaitlyn Elmer, Nathan Tabor

Scholar Week 2016 - present

A project to optimize the drivetrain on the ONU SAE Baja Team vehicle.

Fluid Power Vehicle Challenge, Jacob Torrey, Kayla Londono, Bryson Chan, Aaron Trujillo

Mechanical Engineering

The FPVC combines mechanical engineering disciplines to design and manufacture a vehicle that utilizes hydraulic power. The FDR covers the final manufacturing process and verification processes developed during the front end of research and analysis built upon the Critical Design Review (CDR) and the PDR (Preliminary Design Review). This report showcases the design decisions and extensive research that supports the continuing efforts by the Team Pump My Ride, to build upon the accomplishments of Cal Poly’s previous team, The Incompressibles. The FDR presents how Team Pump My Ride produced the design changes from the CDR and PDR to achieve improvements …