Mechanical 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 …

Molecular And Cellular Level Characterization Of Cytoskeletal Mechanics Using A Quartz Crystal Microbalance, Emily M. Kerivan, Lyle Tobin, Mihir Basil, Dana N. Reinemann

Faculty and Student Publications

A quartz crystal microbalance (QCM) is an instrument that has the ability to measure nanogram-level changes in mass on a quartz sensor and is traditionally used to probe surface interactions and assembly kinetics of synthetic systems. The addition of dissipation monitoring (QCM-D) facilitates the study of viscoelastic systems, such as those relevant to molecular and cellular mechanics. Due to real-time recording of frequency and dissipation changes and single protein-level precision, the QCM-D is effective in interrogating the viscoelastic properties of cell surfaces and in vitro cellular components. However, few studies focus on the application of this instrument to cytoskeletal systems, …

Smart Wifi Thermostat-Enabled Thermal Comfort Control In Residences, Robert Lou, Kevin P. Hallinan, Kefan Huang, Timothy Reissman

Mechanical and Aerospace Engineering Faculty Publications

The present research leverages prior works to automatically estimate wall and ceiling R-values using a combination of a smart WiFi thermostat, building geometry, and historical energy consumption data to improve the calculation of the mean radiant temperature (MRT), which is integral to the determination of thermal comfort in buildings. To assess the potential of this approach for realizing energy savings in any residence, machine learning predictive models of indoor temperature and humidity, based upon a nonlinear autoregressive exogenous model (NARX), were developed. The developed models were used to calculate the temperature and humidity set-points needed to achieve minimum thermal comfort …

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 …

Reflect To Connect, Sophia Rae Guzules

Liberal Arts and Engineering Studies

Engineering statics is an important course and a prerequisite for many subsequent courses for many engineering majors. It is often students’ first exposure to technical engineering sciences. Most statics concepts are addressed in ways disconnected from students’ prior experiences and interests. Utility Value Interventions (UVIs) have been employed in fields like biology and chemistry to help students connect concepts in class and their lives outside the classroom. However, UVI usage in engineering so far has been limited. In this Senior Project paper, I will describe the process that the team Critical Research in Engineering and Technology Education (CREATE) and I …

Modeling The Effects Of Radiation On Microelectromechanical Resonators, David D. Lynes

Theses and Dissertations

As the use of MEMS becomes more prolific in air, space, defense, and power applications, they will be exposed to more extreme radiation environments. This dissertation explores the effects of ionizing and nonionizing radiation on MEMS. AlN-on-Si based piezoelectric bulk acoustic wave resonators were irradiated by gamma-rays and silicon ions while measuring S-parameters in situ. Changes to the resonator and equivalent circuit parameters are extracted. The resonators demonstrated resilience against the effects of radiation-induced charge trapping. However, radiation-induced atomic displacements caused shifts to resonant frequency. From these data, an atomistic model is derived to describe the relationship between radiation type …

Shock Induced Trailing Edge Separation Effect On F-16 Limit-Cycle Oscillation, Eric D. Stubblefield

Theses and Dissertations

No abstract provided.

Ultrasonic Mapping Needle, Katie R. Stone, Stu Bembenek

Mechanical Engineering

When gaining access to a vein or organ for the purpose of ablation or other reasons, the common procedural method of entry is to use the Seldinger technique. This has been the standard entry procedure since its introduction in 1953, and the technique has not been modified during this time. While effective, it is prone to complication as it relies solely on the operator's precision and experience. It is our task and goal to develop a modifying kit for this procedure that would aid the operator in this process. It would make use of mapping technology and standard products used …

Trajectory-Tracking Control Of The Ball-And-Plate System, Dominic E. Riccoboni

Master's Theses

The Mechatronics group in the Mechanical Engineering department of Cal Poly is interested in creating a demonstration of a ball-and-plate trajectory tracking controller on hardware. The display piece will serve to inspire engineering students to pursue Mechatronics and control theory as an area of study. The ball-and-plate system is open-loop unstable, underactuated, and has complicated, nonlinear equations of motion. These features present substantial challenges for control - especially if the objective is trajectory tracking. Because the system is underactuated, common nonlinear trajectory tracking control techniques are ineffective. This thesis lays out a theoretical foundation for controlling the hardware.

Several important …

Recent Advances In Centrifugal Spinning And Their Applications In Tissue Engineering, Shaik Merkatur Hakim Marjuban, Musfira Rahman, Syeda Sharmin Duza, Mohammad Boshir Ahmed, Dinesh K. Patel, Md Saifur Rahman, Karen Lozano

Mechanical Engineering Faculty Publications

Over the last decade, researchers have investigated the potential of nano and microfiber scaffolds to promote wound healing, tissue regeneration, and skin protection. The centrifugal spinning technique is favored over others due to its relatively straightforward mechanism for producing large quantities of fiber. Many polymeric materials have yet to be investigated in search of those with multifunctional properties that would make them attractive in tissue applications. This literature presents the fundamental process of fiber generation, and the effects of fabrication parameters (machine, solution) on the morphologies such as fiber diameter, distribution, alignment, porous features, and mechanical properties. Additionally, a brief …

Automated Combustion Model Classification For Char Particle Distributions Using 3-D Morphology Analysis And Pore-Resolving Cfd Simulations, Dongyu Liang, Simcha L. Singer

Mechanical Engineering Faculty Research and Publications

Combustion of pulverized coal involves millions of particles with a distribution of morphologies. A workflow is presented to characterize, classify, and model distributions of highly porous coal char particles. To understand the impacts of morphology, 3-D pore-resolving combustion simulations for 150 particles imaged with micro-CT are first performed. To facilitate modeling distributions of morphology in reactor-scale CFD, a machine learning algorithm is then trained to classify particles according to their expected combustion behavior and to select an accurate, computationally efficient 1-D particle-scale combustion model. Whereas existing approaches classify particles solely according to morphology and use 2-D measurements, the present approach …

Decomposition Of The Skin-Friction Coefficient Of Compressible Boundary Layers, Dongdong Xu, Pierre Ricco, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We derive an integral formula for the skin-friction coefficient of compressible boundary layers by extending the formula of Elnahhas and Johnson ["On the enhancement of boundary layer skin friction by turbulence: An angular momentum approach, "J. Fluid Mech. 940, A36 (2022)] for incompressible boundary layers. The skin-friction coefficient is decomposed into the sum of the contributions of the laminar coefficient, the change of the dynamic viscosity with the temperature, the Favre-Reynolds stresses, and the mean flow. This decomposition is applied to numerical data for laminar and turbulent boundary layers, and the role of each term on the wall-shear stress is …

Detonation Confinement In A Second-Generation Radial Rotating Engine, John T. Ursino

Theses and Dissertations

In recent years, Rotating Detonation Engines (RDEs) have been coupled with turbomachinery to harness the benefits of detonative combustion. A novel type of RDE, referred to as the disk or Radial RDE (RRDE), has been developed in pursuit of length and weight savings compared to a traditional annular flow RDE. This design includes a disk-shaped device within which reactants flow from the outer radius, detonate, and exit the inner radius. In this paper several modifications have been made to a previously tested RRDE to address issues that arose with the original design. The combustion chamber diameter has been increased to …

Development Of Novel Turbomachinery Manufacturing Methods, Timothy P. Winkler

Theses and Dissertations

Compact turbine engines are of increasing interest as a means of propulsion for small, lightweight, low cost, unmanned aerial systems. This study looks to leverage advancements in novel manufacturing technology to produce turbomachinery components while simultaneously reducing costs and manufacturing time. To determine the feasibility of drop-in replacements for stock components this study focused on several research areas. This included materials research on both polymer-reinforced and ceramic materials, specimen tensile testing to determine temperature-dependent material properties, finite element analysis of multiple candidate materials, design and fabrication of a spin test rig, and physical spin testing of manufactured components to predict …

Optimal Configuration Of Extreme Fast Charging Stations Integrated With Energy Storage System And Photovoltaic Panels In Distribution Networks, Zhouquan Wu, Pradeep Bhat, Bo Chen

Michigan Tech Publications, Part 1

Extreme fast charging (XFC) for electric vehicles (EVs) has emerged recently because of the short charging period. However, the extreme high charging power of EVs at XFC stations may severely impact distribution networks. This paper addresses the estimation of the charging power demand of XFC stations and the design of multiple XFC stations with renewable energy resources in current distribution networks. First, a Monte Carlo (MC) simulation tool was created utilizing the EV arrival time and state-of-charge (SOC) distributions obtained from the dataset of vehicle travel surveys. Various impact factors are considered to obtain a realistic estimation of the charging …

Mechanical Metamaterials, Brent A. Peluso, Oliver T. Parker

Mechanical Engineering

Mechanical metamaterials are an emerging design strategy aimed at tailoring lattice structures to achieve specific properties such as negative Poisson’s ratios and guiding wave propagation. These metamaterials have received increasing attention from various application domains, including medical devices, aerospace, automobile, and infrastructure. The scope of this project is to vary a single lattice parameter and quantify its effect on the structural properties of the given 3D lattice.