Engineering Commons^™

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 …

A Cprbm-Based Method For Large-Deflection Analysis Of Contact-Aided Compliant Mechanisms Considering Beam-To-Beam Contacts, Mohui Jin, Benliang Zhu, Jiasi Mo, Zhou Yang, Xianmin Zhang, Larry L. Howell

Faculty Publications

Contact-aided compliant mechanisms (CCMs) utilize contact to achieve enhanced functionality. The contact phenomenon of CCMs increases the difficulties of their analysis and design, especially when they exhibit beam-to-beam contact. Considering the particularity of CCMs analysis, which is more about the mechanisms’ deformation, this paper presents a numerical method to analyze the large deflection and stress of the CCMs considering beam-to-beam contacts. Based on our previous work on beam-to-rigid contact, the large deformation of general beams in CCMs is modeled by using the chained pseudo-rigid-body model (CPRBM). An approximation based on the geometric information of CPRBM is proposed in this paper …

An Origami-Based Medical Support System To Mitigate Flexible Shaft Buckling, Brandon Sargent, Jared Butler, Kendall Seymour, David Bailey, Brian D. Jensen, Spencer P. Magleby, Larry L. Howell

Faculty Publications

This paper presents the development of an origami-inspired support system (the OriGuide) that enables the insertion of flexible instruments using medical robots. Varying parameters of a triangulated cylindrical origami pattern were combined to create an effective highly-compressible anti-buckling system that maintains a constant inner diameter for supporting an instrument and a constant outer diameter throughout actuation. The proposed origami pattern is composed of two repeated patterns: a bistable pattern to create support points to mitigate flexible shaft buckling and a monostable pattern to enable axial extension and compression of the support system. The origami-based portion of the device is combined …

Heat Set Creases In Polyethylene Terephthalate (Pet) Sheets To Enable Origami-Based Applications, Brandon Sargent, Nathan Brown, Brian D. Jensen, Spencer P. Magleby, William G. Pitt, Larry L. Howell

Faculty Publications

Polyethylene terephthalate (PET) sheets show promise for application in origami-based engineering design. Origami-based engineering provides advantages that are not readily available in traditional engineering design methods. Several processing methods were examined to identify trends and determine the effect of processing of PET sheets on the crease properties of origami mechanisms in PET. Various annealing times, temperatures, and cooling rates were evaluated and data collected for over 1000 samples. It was determined that annealing temperature plays the largest role in crease response. An increase in the crystallinity of a PET sheet while in the folded state likely increases the force response …

Developable Mechanisms On Right Conical Surfaces, Lance P. Hyatt, Spencer P. Magleby, Larry L. Howell

Faculty Publications

An approach for designing developable mechanisms on a conical surface is presented. By aligning the joint axes of spherical mechanisms to the ruling lines, the links can be created in a way that the mechanism conforms to a conical surface. Terminology is defined for mechanisms mapped onto a right cone. Models are developed to describe the motion of the mechanism with respect to the apex of the cone, and connections are made to cylindrical developable mechanisms using projected angles. The Loop Sum Method is presented as an approach to determine the geometry of the cone to which a given spherical …

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 …

On The Modeling Of A Contact-Aided Cross-Axis Flexural Pivot, Pietro Bilancia, Giovanni Berselli, Spencer P. Magleby, Larry L. Howell

Faculty Publications

This paper reports the study of a planar Cross-Axis Flexural Pivot (CAFP) comprising an additional contact pair. The proposed device turns useful for applications requiring a revolute joint that behaves differently when deflecting clockwise/anti-clockwise. The presence of the contact pair reduces the free length of one flexures, resulting in a considerable increment of the overall joint stiffness. The pivot behaviour is investigated, for different load cases, via the ChainedBeam-Constraint Model (CBCM), namely an accurate method to be applied in large deflection problems. A framework comprising Matlab and ANSYS is developed for testing the CAFP performances in terms of rotational stiffness, …

A Design Approach To Fully Compliant Multistable Mechanisms Employing A Single Bistable Mechanism, Yanjie Gou, Guimin Chen, Larry L. Howell

Faculty Publications

A fully compliant multistable mechanism is a monolithic structure that is capable of staying at multiple positions without power input, and has many applications including switches, valves, positioners. However, it is difficult to design such a mechanism because of the complexities of the multistable behavior, the practical stress limits and the buckling constraints. This paper discusses the design approach for fully compliant multistable mechanisms which employs a single bistable mechanism and several end-effectors connected in series. The force-displacement characteristics of the end-effectors are derived using the pseudo-rigid-body model. The design approach to the fully compliant multistable mechanism is provided to …

Design Of Regular 1d, 2d, And 3d Linkage-Based Tessellations, Alden D. Yellowhorse, Nathan Brown, Larry L. Howell

Faculty Publications

Linkage origami is one effective approach for addressing stiffness and accommodating panels of finite size in origami models and tessellations. However, successfully implementing linkage origami in tessellations can be challenging. In this work, multiple theorems are presented that provide criteria for designing origami units or cells that can be assembled into arbitrarily large tessellations. The application of these theorems is demonstrated through examples of tessellations in two and three dimensions.

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 …

Fast-, Light-Cured Scintillating Plastic For 3d-Printing Applications, Brian G. Frandsen, Michael Febbraro, Thomas Ruland, Theodore W. Stephens, Paul A. Hausladen, Juan J. Manfredi, James E. Bevins

Faculty Publications

Additive manufacturing techniques enable a wide range of possibilities for novel radiation detectors spanning simple to highly complex geometries, multi-material composites, and metamaterials that are either impossible or cost prohibitive to produce using conventional methods. The present work identifies a set of promising formulations of photocurable scintillator resins capable of neutron-gamma pulse shape discrimination (PSD) to support the additive manufacturing of fast neutron detectors. The development of these resins utilizes a step-by-step, trial-and-error approach to identify different monomer and cross-linker combinations that meet the requirements for 3D printing followed by a 2-level factorial parameter study to optimize the radiation detection …

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 …

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.

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 …

Zero Torque Compliant Mechanisms Employing Pre-Buckled Beams, Pietro Bilancia, Samuel Porter Smith, Giovanni Berselli, Spencer P. Magleby, Larry L. Howell

Faculty Publications

The concept of a statically balanced mechanism with a single rotational degree of freedom is presented. The proposed device achieves static balancing by combining positive stiff- ness elements and negative stiffness elements within a nuclear domain. Two designs are discussed. The first is composed of an Archimedean spiral and two pinned-pinned pre-buckled beams. The overall mechanism is modeled via an analytical approach and the element dimensions are optimized. The optimal configuration is then tested through finite element analysis (FEA). A second approach replaces the spiral beam with elastic custom-shaped spline beams. An FEA optimization is performed to determine the shape …

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 …

Bipolar Membrane Electrodialysis For Sustainable Utilization Of Inorganic Salts From The Reverse Osmosis Concentration Of Real Landfill Leachate, Hao-Ran Yang, Chi-Qian Zhang, Bing Li, Jia-Cheng Yang, Yu-Ming Zheng, Mohammad Younas, Zhi-Hua Zheng

Faculty Publications

Developing an effective resource utilization method for landfill leachate reverse osmosis concentrate (LLRC) remains a challenge because of the high concentrations of inorganic salts and refractory organic compounds. This study applied a bipolar membrane electrodialysis (BMED) to separate inorganic salts from real LLRC while simultaneously reclaiming inorganic acids and bases. The performance of BMED was affected by operating parameters, such as operating voltage, membrane surface flow velocity, and initial acid-base concentration. With optimized operating parameters, the reclaimed acid-base concentrations, desalination rate, and current efficiency were higher with less energy consumption. Ultimately, 0.41 mol/L acids and 0.40 mol/L bases were reclaimed …

Evaluation Of A Droplet Spraying/Misting System To Enhance Leachate Evaporation And Reduce Leachate Treatment Costs: A Case Study At The Three Rivers Solid Waste Authority Landfill, Kaitlen Drafts, Suzie Boxman, Scott Ribes, Mike Terry, Bryan Staley, Nicole Berge

Faculty Publications

Three Rivers Solid Waste Authority (TRSWA) operates a MSW landfill outside Jack-son, South Carolina at which leachate is stored in a collection pond then trucked to a local wastewater treatment plant (WWTP) for treatment. This landfill operates a droplet spraying/misting system (referred to as the Lilypad system) to enhance leachate evaporation and ultimately reduce the quantity of leachate in the pond that requires subsequent treatment. Little work investigating the efficacy in using such a system to enhance leachate evaporation has been reported. The overall goal associated with this study was to quantify the amount of evaporation enhanced by the droplet …

Evolution Of Coronal Magnetic Field Parameters During X5.4 Solar Flare, Seth H. Garland, Benjamin F. Akers, Vasyl B. Yurchyshyn, Robert D. Loper, Daniel J. Emmons

Faculty Publications

The coronal magnetic field over NOAA Active Region 11,429 during a X5.4 solar flare on 7 March 2012 is modeled using optimization based Non-Linear Force-Free Field extrapolation. Specifically, 3D magnetic fields were modeled for 11 timesteps using the 12-min cadence Solar Dynamics Observatory (SDO) Helioseismic and Magnetic Imager photospheric vector magnetic field data, spanning a time period of 1 hour before through 1 hour after the start of the flare. Using the modeled coronal magnetic field data, seven different magnetic field parameters were calculated for 3 separate regions: areas with surface |Bz| ≥ 300 G, areas of flare brightening seen …

Measured Spectral, Directional Radiative Behavior Of Corrugated Surfaces, Kyle S. Meaker, Ehsan Modfidipour, Matthew R. Jones, Brian D. Iverson

Faculty Publications

Spacecraft thermal control is entirely reliant upon radiative heat transfer with its surroundings for tem- perature regulation. Current methods are often static in nature and do not provide dynamic control of radiative heat transfer. As a result, modern spacecraft thermal control systems are typically ‘cold-biased’ with radiators that are larger than necessary for many operating conditions. Deploying a variable radiator as a thermal control technique in which the projected surface area can be adjusted to provide the appro- priate heat loss for a given condition can reduce unnecessary heat rejection and reduce power require- ments. However, the radiative behavior of …

Prestressed Steel-Concrete Composite I-Beams With Single And Double Corrugated Web, Mahmoud T. Nawar, Ayman El-Zohairy, Hassan M. Maaly, Mohammed Husain

Faculty Publications

Composite steel girders with concrete have been used for many years and advances in structural and fabrication technology have established their optimization. One of the changes in structural steel I-beams during the past few years has been the availability of web corrugation. The economic design of steel girders normally requires thin webs. Moreover, using externally prestressed tendons as a strengthening technique controls deflections and stresses. However, this strengthening technique causes shear buckling of the steel beams. In this study, the flexural behavior of externally prestressed composite steel-concrete I-beams with a single and double corrugated web was experimentally and numerically investigated. …

Dynamic Multi-Dimensional Numerical Transport Study Of Lithium-Ion Battery Active Material Microstructures For Automotive Applications, Joseph S. Lopata, Taylor R. Garrick, Fengkun Wang, Han Zhang, Yangbing Zeng, Sirivatch Shimpalee

Faculty Publications

In support of GM’s traction battery efforts, we derived and implemented a method to describe the electrochemical performance of a battery cell considering the nuances of the electrode microstructure at the anode and the cathode and the corresponding impact on the electrochemical transport in the solid and liquid phases. To assess the capability of the method, we compared model results from the microstructure framework with the commonly used continuum-level porous electrode model, commonly referred to as the pseudo-2-dimensional model, or the Newman Model. The microstructure modeling framework was applied to simulate the electrochemical and transport processes within the battery cell …

Investigation Of Electrically Isolated Capacitive Sensing Skins On Concrete To Reduce Structure/Sensor Capacitive Coupling, Emmanuel Ogunniyi, Alexander Vareen, Austin Downey, Simon Laflamme, Jian Li, Caroline Bennett, William Collins, Hongki Jo, Alexander Henderson, Paul Ziehl

Faculty Publications

Damage to bridges can result in partial or complete structural failures, with fatal consequences. Cracks develop in concrete infrastructure from fatigue loading, vibrations, corrosion, or unforeseen structural displacement. Effective long-term monitoring of civil infrastructure can reduce the risk of structural failures and potentially reduce the cost and frequency of inspections. However, deploying structural health monitoring technologies for crack detection on bridges is expensive, especially long-term, due to the density of sensors required to detect, localize, and quantify cracks. Previous research on soft elastomeric capacitors (SECs) has shown their viability for low-cost monitoring of cracks in transportation infrastructure. However, when deployed …

Sootlib: A Soot Model Library For Combustion Simulation, Victoria B. Stephens, Joshua Bedwell, Alex J. Josephson, Keturah Oldham, David O. Lignell

Faculty Publications

Soot formation in combustion is an important process that affects radiative heat transfer, flame temperatures, and emissions with health and environmental impacts. Soot formation involves complex chemistry for nucleation, growth, oxidation, and coagulation processes. The soot particles vary widely in size and accurate modeling requires representation of the particle size distribution (PSD). Modeling soot is not trivial, and is only one of several physical processes active in combustion systems. This paper presents a software package called SootLib, which is an open-source library for modeling soot formation and other aerosol systems. SootLib is written in C++, is documented with Doxygen, and …

Electron Energization By Inertial Alfvén Waves In Density Depleted Flux Tubes At Jupiter, P. A. Damiano, P. A. Delamere, E.-H. Kim, J. R. Johnson, C. S. Ng

Faculty Publications

Juno satellite observations have illustrated substantial examples of broadband electron energization up to 105–106 eV levels. In order to explain these observations, we use a hybrid gyrofluid kinetic-electron model in an untilted dipolar topology to illustrate energization to high levels in weak current conditions by inertial Alfvén waves close to the Jupiter ionosphere for ambient plasma densities and magnetic field perturbations inferred from Juno satellite observations. The key to the high energization is the extremely low densities evident in the observations which necessitates the acceleration of electrons to very high velocities in order to carry the field-aligned current.

Turbulent Mixing Simulation Using The Hierarchical Parcel-Swapping (Hips) Model, Tommy Starick, Masoomeh Behrang, David O. Lignell, Heiko Schmidt, Alan R. Kerstein

Faculty Publications

Turbulent mixing is an omnipresent phenomenon that permanently affects our everyday life. Mixing processes also
plays an important role in many industrial applications. The full resolution of all relevant flow scales often poses a major challenge to the numerical simulation and requires a modeling of the small-scale effects. In transported Probability Density Function (PDF) methods, the simplified modeling of the molecular mixing is a known weak point. At this place, the Hierarchical Parcel-Swapping (HiPS) model developed by A.R. Kerstein [J. Stat. Phys. 153, 142-161 (2013)] represents a computationally efficient and novel turbulent mixing model. HiPS simulates the effects of turbulence …

How Noise Thresholds Affect The Information Content Of Stellar Flare Sequences, Elmer C. Rivera, Jay R. Johnson, Jonathan Homan, Simon Wing

Faculty Publications

Systems that exhibit discrete dynamics can be well described and reconstructed by considering the set of time intervals between the discrete events of the system. The Kepler satellite has cataloged light curves for many Sun-like stars, and these light curves show strong bursts in intensity that are associated with stellar flares. The waiting time between these flares describes the fundamental dynamics of the stars and is driven by physical processes, such as flux emergence. While it is rather straightforward to identify large flares, the identification of weaker flares can be challenging because of the presence of noise. A common practice …

Changes In The Mechanical Performance Of An Ortho-Planar Spring After Aging Tests, Lucas F. L. Santos, Larry L. Howell, Jose J. R. D’Almeida

Faculty Publications

This paper analyzed an ortho-planar spring (OPS) compliant mechanism and evaluated its mechanical performance after hygrothermal and ultraviolet radiation aging tests. The aging analysis performed here addresses the performance of compliant mechanisms after aging processes which can help inform the design of future compliant mechanisms. ASTM D638 tensile test type I samples were also submitted to aging to serve as a comparison for OPS samples. The samples were submitted to three different kinds of aging conditions, namely water immersion, oil immersion, and ultraviolet radiation. In conclusion, tensile samples showed significant statistical changes in Young's modulus and elongation at break, whereas …

Symmetric Equations For Evaluating Maximum Torsion Stress Of Rectangular Beams In Compliant Mechanisms, Guimin Chen, Larry L. Howell

Faculty Publications

There are several design equations available for calculating the torsional compliance and the maximum torsion stress of a rectangular cross-section beam, but most depend on the relative magnitude of the two dimensions of the cross-section (i.e.,the thickness and the width). After reviewing the available equations, two thickness-to-width ratio independent equations that are symmetric with respect to the two dimensions are obtained for evaluating the maximum torsion stress

of rectangular cross-section beams. Based on the resulting equations, outside lamina emergent torsional joints are analyzed and some useful design insights are obtained. These equations, together with the previous work on symmetric equations …

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 …