Engineering Commons^™

Advancements And Challenges In Additively Manufactured Functionally Graded Materials: A Comprehensive Review, Suhas Alkunte, Ismail Fidan, Vivekanand Naikwadi, Shamil Gudavasov, Mohammad Alshaikh Ali, Mushfig Mahmudov, Seymur Hasanov, Muralimohan Cheepu

Engineering Technology Faculty Publications

This paper thoroughly examines the advancements and challenges in the field of additively manufactured Functionally Graded Materials (FGMs). It delves into conceptual approaches for FGM design, various manufacturing techniques, and the materials employed in their fabrication using additive manufacturing (AM) technologies. This paper explores the applications of FGMs in diverse fields, including structural engineering, automotive, biomedical engineering, soft robotics, electronics, 4D printing, and metamaterials. Critical issues and challenges associated with FGMs are meticulously analyzed, addressing concerns related to production and performance. Moreover, this paper forecasts future trends in FGM development, highlighting potential impacts on diverse industries. The concluding section summarizes …

A Personal Tribute To Professor Ashok Midha, Larry L. Howell

Faculty Publications

When I received the news that Professor Ashok Midha had passed away, I was grieved by the unexpected news. But I also felt another emotion: gratitude for having known him. I am grateful for him, for the opportunity I had to learn from him, and for the influence he has had on my life and career. I wanted to honor his memory in some way. This document is in response to that desire.

Some of my thoughts at his passing are summarized in the first chapter and the conclusion. The other writing is taken from a draft of my personal …

The Potential Of The Implementation Of Offline Robotic Programming Into Automation-Related Pedagogy, Max Rios Carballo, Xavier Brown

Publications and Research

In this study, the offline programming tool RoboDK is used to program industrial robots for the automation sector. The study explores the feasibility of using this non-disruptive robot programming software for classroom use; assesses how well RoboDK can be used to program various robots used in the industry; creates and tests various applications; and pinpoints technical obstacles that prevent a smooth link between offline programming and actual robots. Initial results indicate that RoboDK is an effective tool for deploying its offline programming code to a Universal Robot, UR3e. There are many potential for advanced applications. The goal of the project …

Large Deflection Analysis Of General Beams In Contact-Aided Compliant Mechanisms Using Chained Pseudo-Rigid-Body Model, Mohui Jin, Collin Ynchausti, Xianmin Zhang, Zhou Yang, Benliang Zhu, Larry L. Howell

Faculty Publications

The nonlinear analysis and design of contact-aided compliant mechanisms (CCMs) are challenging. This paper presents a nonlinear method for analyzing the deformation of general beams that contact rigid surfaces in CCMs. The large deflection of the general beam is modeled by using the chained pseudo-rigid-body model. A geometry constraint from the contact surface is developed to constrain the beam’s deformed configuration. The contact analysis problem is formulated based on the principle of minimum potential energy and solved using an optimization algorithm. Besides, a novel technique based on the principle of work and energy is proposed calculate the reaction force/moment of …

A Model For Multi-Input Mechanical Advantage In Origami-Based Mechanisms, Jared Butler, Adam Shrager, Timothy Simpson, Landen Bowen, Mary Frecker, Robert Lang, Eric Wilcox, Paris Von Lockette, Larry L. Howell, Spencer P. Magleby

Faculty Publications

Mechanical advantage is traditionally defined for single input and single-output rigid-body mechanisms. A generalized approach for identifying single-output mechanical advantage for a multiple-input compliant mechanism, such as many origami-based mechanisms, would prove useful in predicting complex mechanism behavior. While origami-based mechanisms are capable of offering unique solutions to engi neering problems, the design process of such mechanisms is complicated by the interaction of motion and forces. This paper presents a model of the mechanical advantage for multi input compliant mechanisms and explores how modifying the parameters of a model affects their behavior. The model is used to predict the force-deflection …

Finite Element Modeling Of Meniscal Tears Using Continuum Damage Mechanics And Digital Image Correlation, Derek Q. Nesbitt, Dylan E. Burruel, Bradley S. Henderson, Trevor J. Lujan

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Meniscal tears are a common, painful, and debilitating knee injury with limited treatment options. Computational models that predict meniscal tears may help advance injury prevention and repair, but first these models must be validated using experimental data. Here we simulated meniscal tears with finite element analysis using continuum damage mechanics (CDM) in a transversely isotropic hyperelastic material. Finite element models were built to recreate the coupon geometry and loading conditions of forty uniaxial tensile experiments of human meniscus that were pulled to failure either parallel or perpendicular to the preferred fiber orientation. Two damage criteria were evaluated for all experiments: …

Kinetostatic And Dynamic Modeling Of Flexure-Based Compliant Mechanisms: A Survey, Mingxiang Ling, Larry L. Howell, Junyi Cao, Guimin Chen

Faculty Publications

Flexure-based compliant mechanisms are becoming increasingly promising in precision engineering, robotics and other applications due to the excellent advantages of no friction, no backlash, no wear, and minimal requirement of assembly. Because compliant mechanisms have inherent coupling of kinematic- mechanical behaviors with large deflections and/or complex serial-parallel configurations, the kinetostatic and dynamic analyses are challenging in comparison to their rigid-body counterparts. To address these challenges, a variety of techniques have been reported in a growing stream of publications. This paper surveys and compares the conceptual ideas, key advances, applicable scopes and open problems of the state-of-the-art kinetostatic and dynamic modeling …

Rigidly Foldable Thick Origami Using Designed-Offset Linkages, Robert J. Lang, Nathan Brown, Brian Ignaut, Spencer P. Magleby, Larry L. Howell

Faculty Publications

We present new families of thick origami mechanisms that achieve rigid foldability and parallel stacking of panels in the flat-folded state using linkages for some or all of the hinges between panels. A degree-four vertex results in a multi-loop eight-bar spatial mechanism that can be analyzed as separate linkages. The individual linkages are designed so that they introduce offsets perpendicular to the panels that are mutually compatible around each vertex. This family of mechanisms offers the unique combination of a planar unfolded state, parallel-stacked panels in the flat folded state, and kinematic single-degree-of-freedom motion from the flat- unfolded to the …

Membrane-Enhanced Lamina Emergent Torsional Joints For Surrogate Folds, Guimin Chen, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Lamina emergent compliant mechanisms (including origami-adapted compliant mechanisms) are mechanical devices that can be fabricated from a planar material (a lamina) and have motion that emerges out of the fabrication plane. Lamina emergent compliant mechanisms often exhibit undesirable parasitic motions due to the planar fabrication constraint. This work introduces a type of lamina emergent torsion (LET) joint that reduces parasitic motions of lamina emergent mechanisms (LEMs), and presents equations for modeling parasitic motion of LET joints. The membrane joint also makes possible one-way joints that can ensure origami-based mechanisms emerge from their flat state (a change point) into the desired …

Deployable Convex Generalized Cylindrical Surfaces Using Torsional Joints, Todd G. Nelson, Jared T. Burton, Curtis G. Nelson, Luis M. Baldelomar Pinto, Zhicheng Deng, Larry L. Howell

Faculty Publications

The ability to deploy a planar surface to a desired convex profile with a simple actuation can enhance foldable or morphing airfoils, deployable antennae and reflectors, and other applications where a specific profile geometry is desired from a planar sheet. A model using a system of rigid links joined by torsional springs of tailorable stiffness is employed to create an approximate curved surface when two opposing tip loads are applied. A system of equations describing the shape of the surface during deployment is developed. The physical implementation of the model uses compliant torsion bars as the torsion springs. A multidimensional …

Limits Of Extramobile And Intramobile Motion Of Cylindrical Developable Mechanisms, Jared Butler, Larry L. Howell, Spencer P. Magleby, Jacob Greenwood

Faculty Publications

Mechanisms that can both deploy and provide motions to perform desired tasks offer a multifunctional advantage over traditional mechanisms. Developable mechanisms (DMs) are devices capable of conforming to a predetermined developable surface and deploying from that surface to achieve specific motions. This paper builds on the previously identified behaviors of extramobility and intramobility by introducing the terminology of extramobile and intramobile motion, which define the motion of developable mechanisms while interior and exterior to a developable surface. The limits of motion are identified using defined conditions. It is shown that the more difficult of these conditions to kinematically predict may …

Analysis Of The Rigid Motion Of A Conical Developable Mechanism, Mckell Woodland, Michelle Hsiung, Erin L. Matheson, C Alex Safsten, Jacob Greenwood, Denise M. Halverson, Larry L. Howell

Faculty Publications

We demonstrate analytically that it is possible to construct a developable mechanism on a cone that has rigid motion. We solve for the paths of rigid motion and analyze the properties of this motion. In particular, we provide an analytical method for predicting the behavior of the mechanism with respect to the conical surface. Moreover, we observe that the conical developable mechanisms specified in this paper have motion paths that necessarily contain bifurcation points which lead to an unbounded array of motion paths in the parameterization plane.

Load-Displacement Characterization In Three Degrees Of Freedom For General Let Arrays, Nathan A. Pehrson, Pietro Bilancia, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Lamina emergent torsion (LET) joints for use in origami-based applications enables folding of panels. Placing LET joints in series and parallel (formulating LET arrays) opens the design space to provide for tunable stiffness characteristics in other directions while maintaining the ability to fold. Analytical equations characterizing the elastic load-displacement for general serial-parallel formulations of LET arrays for three degrees of freedom are presented: rotation about the desired axis, in-plane rotation, and extension/compression. These equations enable the design of LET arrays for a variety of applications, including origami-based mechanisms. These general equations are verified using finite element analysis and, to show …

Conceptualizing Stable States In Origami-Based Devices Using An Energy Visualization Approach, Jacob Greenwood, Larry L. Howell, Alex Avila, Spencer P. Magleby

Faculty Publications

In many origami-based applications, a device needs to be maintained in one or more fold states. The origami stability integration method (OSIM) presented in this paper pro- vides an approach for graphically combining various techniques to achieve stability. Existing stability techniques are also categorized into four groups based on whether they are intrinsic or extrinsic to the origami pattern and whether they exhibit gradual or non-gradual energy storage behaviors. These categorizations can help designers select appropriate techniques for their applications. The paper also contains de- sign considerations and resources for achieving stability. Finally, two case studies are presented that use …

Membrane-Enhanced Lamina Emergent Torsional Joints For Surrogate Folds, Guimin Chen, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Lamina emergent compliant mechanisms (including origami-adapted compliant mechanisms) are me- chanical devices that can be fabricated from a planar material (a lamina) and have motion that emerges out of the fabrication plane. Lamina emergent compliant mechanisms often exhibit undesirable para- sitic motions due to the planar fabrication constraint. This work introduces a type of lamina emergent torsion (LET) joint that reduces parasitic motions of lamina emergent mechanisms (LEMs), and presents equations for modeling parasitic motion of LET joints. The membrane joint also makes possible one-way joints that can ensure origami-based mechanisms emerge from their flat state (a change point) into …

Origami-Inspired Sacrificial Joints For Folding Compliant Mechanisms, Todd G. Nelson, Alex Avila, Larry L. Howell, Just L. Herder, Davood Farhadi Machekposhtic

Faculty Publications

Folding is a manufacturing method which can create complex 3D geometries from flat materi- als and can be particularly useful in cost-sensitive or planar-limited fabrication applications.

This paper introduces compliant mechanisms that employ folding techniques from origami to evolve from a flat material to deployed state. We present origami-inspired sacrificial joints, joints which have mobility during assembly of the mechanism but are rigid in their final position, to create regions of high and low stiffness and the proper alignment of compliant flexures in folded mechanisms. To demonstrate the method we fold steel sheet to create some well-known and complex compliant …

Regional Stiffness Reduction Using Lamina Emergent Torsional Joints For Flexible Printed Circuit Board Design, Bryce P. Defigueiredo, Brian Dale Russell, Trent K. Zimmerman, Larry L. Howell

Faculty Publications

Flexible printed circuit boards (PCBs) make it possi- ble for engineers to design devices that use space efficiently

and can undergo changes in shape and configuration. How- ever, they also suffer from trade-offs due to non-ideal mate- rial properties. Here, a method is presented that allows en- gineers to introduce regions of flexibility in otherwise rigid

PCB substrates. This method employs geometric features to reduce local stiffness in the PCB, rather than reducing

the global stiffness by material selection. Analytical and fi- nite element models are presented to calculate the maximum

stresses caused by deflection. An example device is produced …

Normalized Coordinate Equations And Energy Method For Predicting Natural Curved-Fold Configurations, Jacob Badger, Todd G. Nelson, Rober J. Lang, Denise M. Halverson, Larry L. Howell

Faculty Publications

Of the many valid configurations that a curved fold may assume, it is of particular interest to identify natural—or lowest energy—configurations that physical models will preferentially assume. We present normalized coordinate equations—equations that relate fold surface properties

to their edge of regression—to simplify curved-fold rela- tionships. An energy method based on these normalized

coordinate equations is developed to identify natural con- figurations of general curved folds. While it has been noted

that natural configurations have nearly planar creases for curved folds, we show that non-planar behavior near the crease ends substantially reduces the energy of a fold.

Origami-Based Design Of Conceal-And-Reveal Systems, Bryce P. Defigueiredo, Kyler A. Tolman, Spencer P. Magleby, Nathan A. Pehrson, Erica Crampton, Larry L. Howell

Faculty Publications

This work introduces a type of motion termed “conceal-and-reveal” which is characterized by a state that protects a payload, a state that exposes the payload, and coupled motions between these two states. As techniques for thick, rigid origami-based engineering designs are being developed, origami is becoming increasingly more

attractive as inspiration for complex systems. This paper proposes a process for designing origami-based conceal- and-reveal systems, which can be generalized to design similar thick, rigid origami-based systems. The process

is demonstrated through the development of three conceal-and-reveal systems that present a luxury product to the consumer. The three designs also confirm …

A Pseudo-Static Model For Dynamic Analysis On Frequency Domain Of Distributed Compliant Mechanisms, Mingxiang Ling, Larry L. Howell, June Cao, Zhou Jiang

Faculty Publications

This paper presents a pseudo-static modeling methodology for dynamic analysis of distributed compliant mechanisms to provide accurate and efficient solutions. First, a dynamic stiffness matrix of the flexible beam is deduced, which has the same definition and a similar form as the traditional static compliance/stiffness matrix but is frequency-dependent. Second, the pseudo-static modeling procedure for the dynamic analysis is implemented in a statics-similar way. Then, all the kinematic, static and dynamic performances of compliant mechanisms can be analyzed based on the pseudo- static model. The superiority of the proposed method is that when it is used for the dynamic modeling …

An Alternate Dimensionless Form Of The Linearized Rigid-Body Aircraft Equations Of Motion With Emphasis On Dynamic Parameters, Douglas F. Hunsaker, Benjamin C. Moulton

Mechanical and Aerospace Engineering Student Publications and Presentations

The equations of motion for an aircraft can be linearized about a reference condition within the assumptions of small disturbances and linear aerodynamics. The resulting system of equations is typically solved to obtain the eigenvalues and eigenvectors that describe the small disturbance motion of the aircraft. Results from such an analysis are often used to predict the rigid-body dynamic modes of the aircraft and associated handling qualities. This process is typically carried out in dimensional form in most text books, or in nondimensional form using dimensionless parameters rooted in aerodynamic theory. Here we apply Buckingham’s Pi theorem to obtain nondimensional …

Simplified Mass And Inertial Estimates For Aircraft With Components Of Constant Density, Benjamin C. Moulton, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

Aircraft mass and inertial properties are required for predicting the dynamics and handling qualities of aircraft. However, such properties can be difficult to estimate since these depend on the external shape and internal structure, systems, and mass distributions within the airframe. Mass and inertial properties of aircraft are often predicted using computer-aided design software, or measured using various experimental techniques. The present paper presents a method for quickly predicting the mass and inertial properties of complete aircraft consisting of components of constant density. Although the assumption of constant density may appear limiting, the method presented in this paper can be …

Mmteg Heatsink Design, Peyton Nienaber, Kadin Feldis, Alec Savoye, Jack Waeschle

Mechanical Engineering

In this document, Cal Poly Senior Design Team F16 presents a summary of its work developing a suitable heatsink for Gas Technology Institute’s Methane Mitigation Thermoelectric Generator. After several months of iterating between experimental testing and simulated heat transfer, a suitable prototype was selected for use in further refining simulation parameters. This was called the structural prototype and it allowed Team F16 to confirm several remaining unknowns relating to component thermal conductivity. All documentation of this process can be found in Preliminary, Critical, and Interim Design Review documents (PDR, CDR, IDR), included in this report. Having a realistic model …

Student Understanding Of Kinematics: A Qualitative Assessment, Andrew Cashman, Tom O'Mahony

Publications

In engineering, kinematics is widely regarded as a fundamental topic with the literature agreeing that students possess a wide range in understanding of the topic. This study aims to take a second-order approach by understanding and exploring the qualitatively different ways in which students approach solving kinematics problems. Phenomenography was used to collect data through ten semi-structured interviews with early-stage mechanical engineering students. Following data analysis, four distinct categories of students’ approaches were identified; unstructured, framing the problem, strategic, and conceptual. It was found that these categories could be arranged in a hierarchy and were also supported by secondary epistemic …

Golf Club Cleaner, Owen Roach, Chris Wertenberger, Michael Skerlong

Williams Honors College, Honors Research Projects

Cleaning golf clubs can be a tedious process, however a necessary one to maintain equipment. Clubs are normally cleaned by filling a bucket with soap and water, soaking all the clubs to be cleaned, then scrubbing each one individually. An automatic club cleaner would make this process much easier and more enjoyable. Using electric motors, the club cleaner would have spinning brushes in soap and water to quickly and easily clean the club head. The machine would have different sections for cleaning the club head, polishing the club face, and cleaning the grip. The cleaner should be inexpensive and easy …

Creating Reel Designs: Reflecting On Arthrogryposis Multiplex Congenita In The Community, Iris Layadi

Purdue Journal of Service-Learning and International Engagement

Because of its extreme rarity, the genetic disease arthrogryposis multiplex congenita (AMC) and the needs of individuals with the diagnosis are often overlooked. AMC refers to the development of nonprogressive contractures in disparate areas of the body and is characterized by decreased flexibility in joints, muscle atrophy, and developmental delays. Colton Darst, a seven-year-old boy from Indianapolis, Indiana, was born with the disorder, and since then, he has undergone numerous surgical interventions and continues to receive orthopedic therapy to reduce his physical limitations. His parents, Michael and Amber Darst, have hopes for him to regain his limbic motion and are …

Electrical Characterization Of Phytoplankton Suspensions Using Impedance Spectroscopy., Margaret R Jett

Electronic Theses and Dissertations

Phytoplankton are closely monitored because of their important environmental role, and the impacts they have on their local ecosystems. Some phytoplankton respond to stress by producing lipids, which can be harvested for biofuels and other chemicals. Microfluidic devices have been important in improving the portability and throughput of phytoplankton characterization methods, increasing their potential for in situ use. This study utilized a small sample of phytoplankton suspended in a stagnant medium and measured the impedance response using a lab-on-chip and impedance analyzer. The individual cell characteristics were derived from the impedance response of the group. The goal was to characterize …

Material Detection With Thermal Imaging And Computer Vision: Potentials And Limitations, Jared Poe

Graduate Theses and Dissertations

The goal of my masters thesis research is to develop an affordable and mobile infraredbased environmental sensoring system for the control of a servo motor based on material identification. While this sensing could be oriented towards different applications, my thesis is particularly interested in material detection due to the wide range of possible applications in mechanical engineering. Material detection using a thermal mobile camera could be used in manufacturing, recycling or autonomous robotics. For my research, the application that will be focused on is using this material detection to control a servo motor by identifying and sending control inputs based …

Frequency Domain Measurements Of Melt Pool Recoil Force Using Modal Analysis, Tristan Cullom, Cody Lough, Nicholas Altese, Douglas Bristow, Robert Landers, Ben Brown, Troy Hartwig, Andrew Barnard, Jason Blough, Kevin Johnson, Edward Kinzel

Michigan Tech Publications

Recoil pressure is a critical factor affecting the melt pool dynamics during Laser Powder Bed Fusion (LPBF) processes. Recoil pressure depresses the melt pool. When the recoil pressure is low, thermal conduction and capillary forces may be inadequate to provide proper fusion between layers. However, excessive recoil pressure can produce a keyhole inside the melt pool, which is associated with gas porosity. Direct recoil pressure measurements are challenging because it is localized over an area proportionate to the laser spot size producing a force in the mN range. This paper reports a vibration-based approach to quantify the recoil force exerted …

Human Powered Vehicle Capstone, Maya L. Washington, Ryan Apolonio, Marc Sunga, John Rettenmier, Dr. Allen Wilson

Honors Thesis

In the ASME Human Powered Vehicle Challenge (HPVC), students design, develop, construct, and test different designs of human-powered vehicles. The design utilizes two wheels, the rear of which is responsible for power transmission from a pedal crank and braking through a disc and caliper. The design also utilizes the front wheel fork wheel for steering. Steering and braking are controlled by two levers on the handlebars. To determine whether the design was sufficient, it was compared to the standards set by ASME, including maximum weight, minimum speed, minimum turning radius, minimum ride distance, load testing, harness verification, and a complete …