bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Non-Linear Dynamics of a Shape Memory Alloy Wire Bundle Actuator
Authors: Mosley Michael J. , Mavroidis Constantinos 
Published: December 2021

Abstract
In this paper, the non-linear dynamics of a new Shape Memory Alloy (SMA) actuator that possesses impressive payload lifting capabilities are presented. This actuator consists of 48 SMA wires mechanically bundled in parallel forming one powerful muscle. It was designed to lift up to 100 lbs., which is approximately 300 times its weight. This SMA actuator was tested in open loop experiments with different loads and different inputs, such as step, ramp, sinusoid, and half sinusoid, and its dynamic characteristics were evaluated. An important observation made during the dynamic analysis was the unpredictability of the actuator’s response when low to moderate voltages are applied. This characteristic strongly suggests chaotic behavior of the actuator, which could potentially cause control difficulties in fine and high accuracy tasks. An investigation into chaos was conducted using time histories, phase plots, and Poincaré maps. As shown in the diagrams presented in this paper, system response to larger input voltages is periodic, whereas lower input voltages produce responses that strongly indicate chaotic behavior.
An Optimization Based Approach for Determining Whether a Set of Elementary Contacts Is Geometrically Feasible
Authors: Goeree Barry B. , Fasse Ernest D. , Marefat Michael M. 
Published: December 2021

Abstract
The contact between two polyhedral objects can be represented with a set of elementary contacts — surface-vertex and edge-edge contacts. However, not all possible contact representations are geometrically possible. An equivalent optimization problem is posed to verify geometric feasibility. A steepest descent algorithm has been implemented and applied to two test cases — one feasible and one infeasible contact representation. The results of this work can be used to implement a predicate that verifies whether a contact representation is geometrically possible. The predicate can be used in a generate-and-test paradigm to synthesize the entire contact space.
Micromagnetic In-Process Surface Integrity Analysis of Ground Workpieces
Authors: Tönshoff H. K. , Mandrysch T. 
Published: December 2021

Abstract
In production engineering, especially in grinding processes, the thermal damage has a significant influence on the quality and thus on the reliability of heavy loaded components. Therefore different micromagnetic sensor systems for the nondestructive detection of residual stresses, surface hardness, depth of hardness and partly for the avoidance of grinding burn have been developed. The current research concentrates on a continuous inspection of the quantities mentioned to enable a so-called in-process inspection as well as a 100% quality documentation during, before and after the machining process. No further additional post-process measurements are necessary.
Experimental Study of Virtual Tools With Attributes
Authors: Kesavadas T. , Subramaniam Hari 
Published: December 2021

Abstract
Use of synthetic and surrogate tools in training robots and planning events within virtual environments has tremendous potential in making programming of complex machines simple and easy. In our research we have experimented the use of attribute laden virtual tools in various tasks such as robotic-based grinding and welding processes. Such attribute laden virtual tools aid human operators in path planning as well as in making decisions about the process itself. In this paper we have tested our concepts of virtual tools and the use of attributes such as physical, reflex and command actions. Four sets of experiments were conducted with human subjects. Two kinds of virtual tools were used in these experiments, one with guide plane attributes and the other without them. One set of experiment tested human performance using the head mounted display interface and the effect of learning process in using the virtual tool. Results showed that there was marked improvement in task execution time using the tools laden with guide plane attributes over the unencumbered virtual tools. This paper discusses various future applications of these virtual tools in manufacturing. It is observed that unlike non-haptic visual interfaces, where no physical feed back is available to the user, attribute laden tools can provide a much easier interface to robots.
Dynamic Stability Analysis of Spur Gears in a Steady State
Authors: Oh Sejoong , Grosh Karl , Barber James R. 
Published: December 2021

Abstract
In the previous work by the authors (Oh et al. (1998)), it was shown that in order for the model of an interacting spur gear pair to conserve energy, the dependence of the mesh stiffness on the mean rotation must be included in deriving the equations of motion. A quadratic nonlinearity arises from the dependence of the mesh stiffness on the mean rotation, even under the assumption of small deflection. This nonlinearity ensures conservation of energy. In this study, the stability of the steady-state response of interacting spur gears, both for the new equation of motion (EOM) and the classical EOM, is investigated. The map for periodic orbits is determined and a linearized stability analysis is performed. Once the stability is determined, the comparison between the classical and the new EOM is made for a primary, a secondary sub-harmonic, and super-harmonic resonances. The frequency-amplitude curve from direct simulation is compared to the stability analysis. The effect on the stability by the nonlinear jump term is shown, as well as by the variable time. The effect of damping and the magnitude of the applied torque on the stability is shown.
Optimization of an Automotive Structure Subject to Harmonic Excitation
Authors: Garcia Arnoldo , Lumsdaine Arnold , Yao Ying 
Published: December 2021

Abstract
Optimization theory has been used to obtain solutions to a variety of engineering problems involving beam vibration. In this study, the objective is to design a structure that uses the minimum amount of material. The structure examined is a beam undergoing coupled bending and torsion, as is common in automotive structure beams.
The objective of this study is to minimize the weight of an automotive structure subject to harmonic excitation. The automotive structure is modeled with beam elements in I-DEAS, a computer-aided engineering and finite element software. For each given length, its cross-sectional area is optimized by a discrete finite element method.
In addition, a bracket was modeled in conjunction with the automotive structure. Although the optimal design of beams undergoing forced harmonic loading is available in the literature, to the authors’ knowledge, optimal design of such structures including an intermediate support have not been considered. The placement of the bracket was also treated as a design parameter by varying its location and size in the optimization process. Results show that the total mass after optimization had a mass reduction of 91% when compared to the original weight.
Acoustic Radiation From Mild Steel Plates of Various Thicknesses and Aspect Ratios Excited by a 120 Tonne Press
Authors: Eager David B. M. 
Published: December 2021

Abstract
The critical frequencies for 3, 4 and 5 mm thick flat rectangular mild steel plates of surface areas varying from 0.3 to 3.0 m2 were obtained experimentally using a 120 tonne expanded-metal press. The critical frequencies were noted to increase with decreasing plate thickness and constant for varying perimeter and surface area. The measured values of the critical frequency compared closely with published theoretical data for similar plate parameters.
Modeling and Imaging Flexural Plate Wave Devices
Authors: Adkins D. R. , Schubert W. K. , Butler M. A. , Chu A. S. 
Published: December 2021

Abstract
Sandia National Laboratories is developing a new form of flexural plate wave device (FPW) for sensor applications. In this device, Lorentz forces cause out of plane vibrations in a silicon nitride membrane. Current induced in transducer lines on the membrane provides information about the amplitude and phase of these surface vibrations. By tracking the large amplitude vibrations that occur at resonant frequencies, it is possible to infer information about loading on the membrane. In fabricating FPWs, it is important to understand the impact that minor defects can have on operation. Through modeling and testing, we are developing resilient designs that provide large amplitude signals with a high tolerance to defects. A finite element model has been developed to perform design trade-off studies, and results from the model are being verified with a unique measurement system that can image Angstrom scale displacements at vibrational frequencies up to 800 kHz. Results from FPW modeling and imaging efforts are presented in this paper.
Sputtered Silicon for Microstructures and Microcavities
Authors: Honer Kenneth A. , Kovacs Gregory T. A. 
Published: December 2021

Abstract
Sputtered silicon can be used to make released microstructures at temperatures compatible with prefabricated aluminum-metallized CMOS circuitry. The fabrication sequence is similar to LPCVD polysilicon processes and involves a wet release from an oxide sacrificial layer. This process was used to fabricate a variety of test structures, including cantilevers, combs, and spirals. During release of the structures porosity to HF was observed in films up to 5 μm thick. This porosity resulted in the formation of completely enclosed cavities formed beneath silicon membranes over oxide sacrificial layers, and may have implications for the packaging of released devices. Several properties of the sputtered silicon films were investigated, including their in-plane stress, strain gradient, film density, surface roughness, electrical resistivity, and permeability. The dependency of these properties on deposition power, pressure, and film thickness as well as the effects of low-temperature annealing were also investigated.
Optical Vibration and Acceleration Sensor With a Silicon Cantilever
Authors: Kimura Mitsuteru , Toshima Katsuhisa , Satoh Harunobu 
Published: December 2021

Abstract
A new type all optical vibration and acceleration sensor using the combination of micromachined Si cantilever and optical fiber is proposed, and its fundamental characteristics are demonstrated. The light emitted from bulb-lens set into the V-groove is reflected at the reflector formed on the Si cantilever and then recoupled into the bulb-lens. Several sensors with different length (0.64–6.0 mm long) of the Si cantilever are fabricated to compare the theoretical resonance frequency fr obtained from the simple model and experimental ones. They had good agreement. From the sensing principle the sensing frequency range of the vibration is suitable below the fr of the Si cantilever of the sensor.
Extensive Experimental Study on Diaphragm-Based Piezoelectric Microphone
Authors: Niu Meng-Nian , Zeng Hong , Yan Hai , Kim Eun Sok 
Published: December 2021

Abstract
This paper reports our extensive experimental study on diaphragm-based piezoelectric microphones fabricated on a silicon substrate. We have fabricated and carefully analyzed about 60 micromachined piezoelectric microphones (composed of piezoelectric ZnO film, insulating layers and electrodes) built on a low-stress silicon nitride diaphragm (with and without corrugation on the diaphragm and with five kinds of residual stress in the diaphragm). Microphone sensitivity is measured in an acoustic chamber with a B&K4135 microphone. Vertical displacement of a microphone diaphragm under an applied acoustic pressure is measured with a focused-beam laser Doppler displacement meter. Our results show that (1) corrugation releases both tensile stress and compressive stress effectively, and increases the center displacement greatly, (2) a good bending curvature in the active area is needed for a good microphone sensitivity, and (3) ZnO structural integrity is the major factor that affects the bending curvature in the active area.
Partly Disposable Switching and Injection Microvalves for Medical Applications
Authors: Sato Hironobu , Shoji Shuichi , Kim Eipin , Miura Keisuke 
Published: December 2021

Abstract
Two types of one-inlet and four-outlets pneumatic microvalves for medical applications were fabricated and evaluated. Since the microvalves consist of a separable actuator part and a channel part, the channel part in which the sample liquid are introduced can be partly disposed. Both parts were fabricated using Si and polymer membrane. Two types of polymer membranes of silicone rubber and new cyclized perfluoro polymer (CPFP) were utilized in different types of microvalves for controlling high viscosity and low viscosity samples. In the case of the switching valve using silicone membrane, leakage was less than 0.01 μl/min (inlet pressure of 1mH2O) and the maximum open/closed flow ratio is larger than 105. These microvalves are useful in parallel and multi sensing systems. To achieve the monitoring the pneumatic actuation, integration of piezoresistive pressure sensors on the actuator part was also carried out.
An Integrated Reservoir for On-Chip Aqueous Storage in Microfluidic Systems
Authors: Patel Manoj , Henderson H. Thurman , Bhansali Shekhar , Ahn Chong H. 
Published: December 2021

Abstract
A reservoir for a silicon-based “lab-on-a-chip” integrated microfluidic system has been designed, fabricated and initially characterized. The reservoirs are necessary for storing reagents, antibodies and buffers required for on-chip capture of target microorganisms in this work. Aside from the matter of storing fluids and providing a pressure head for flow or flow augmentation one has the issue of biochemical compatibility of the contact surface. Where one does not desire a pressure head, a mere bio-chemically compatible “collapsible” bag is desired. All these factors are included in the device. This paper reports design issues, fabrication, packaging and initial characterization of the reservoirs. Scaling possibilities are essentially unlimited, however in this case standard reservoirs have been developed in modules of 1/8 and 1 ml capacity.
Coupled Electrostatics-Structures-Fluidic Simulations of a Bead Mesopump
Authors: Athavale M. M. , Li H. Y. , Yang H. Q. , Przekwas A. J. , Cabuz C. , Herb W. 
Published: December 2021

Abstract
A novel microfluidic pump called bead mesopump was analyzed using numerical tools for performance predictions. An electrostatically actuated diaphragm produces pumping action, with appropriately placed inlet and outlet channels for flow rectification. For the first time ever, coupled, transient electrostatics-structures-flow simulations were successfully performed on this complex problem. Simulation data compare well with the available experimental test data. Simulations clearly show the presence of squeeze film flow, and its effects on actuation times and voltages. Simulations of different chamber and electrode designs were also completed to assess effects on pump performance. Numerical simulation tools for MEMS are thus shown to be of significant use in future for analysis of new pump designs, and device optimization.
Micro-Channels With Suspended Temperature Sensors for Heat Transfer Study
Authors: Jiang Linan , Wang Yuelin , Wong Man , Zohar Yitshak 
Published: December 2021

Abstract
A micro-system consisting of micro-channels with integrated temperature sensors was successfully designed and fabricated for the study of heat-transfer properties of fluid flow in micro-domains. Surface micro-machining technology was used to construct the micro-channels with dimensions of about 40μm × 1.4μm × 4000μm. Polysilicon thermistors, 4μm × 4μm × 0.4μm in size were suspended across the channels and directly exposed to the fluid for local temperature measurements. The micro-channels and the micro-sensors were calibrated prior to the heat-transfer studies. Experimental results of temperature distributions along a micro-channel are presented. The integrated micro-system performance was analyzed to provide a framework for the interpretation of the experimental data, and the various heat-transfer mechanisms are subsequently discussed.
In Situ Dynamics of Concentrated DNA Molecules in a Shear Flow
Authors: LeDuc Philip , Pfister Bryan , Xu Yangqing , Wirtz Denis , Bao Gang 
Published: December 2021

Abstract
Polymer dynamics has been studied for many years because of its importance in many areas including materials, mechanics, biology, and medicine (Munk, 1989; Hoffman, et al., 1984). The dynamics of macromolecules in shear flow has been studied using light scattering and birefringence, but the effect of shear on the dynamics of individual polymers is not well understood (Doi & Edwards, 1986; de Gennes, 1991; de Gennes, 1997). Recently we studied the conformational changes of DNA molecules under shear in dilute concentration (LeDuc et al., 1998). Here we report the observations of the dynamics of fluorescently-labeled DNA molecules in a shear flow with increased concentration. Under a controlled shear flow, these flexible polymers exhibit various extended conformations, which range from parallel to perpendicular in orientation when compared to the flow direction. The amount of stretching that occurs in these experiments is found to be less than that for the dilute concentrations of the DNA solutions. Further, the stretching of the molecular solutions is found even at shear rates much smaller than the inverse of the relaxation time of the molecule. The in situ observations also reveal the effect of polymer concentration on the entanglement of macromolecules. These results provide insight into the behavior of individual and concentrated polymer molecules under shear and help further development of models for polymer dynamics (Perkins, et al., 1994; Smith, et al., 1992; Wirtz, 1995).
Panel Discussion: Fluid Mechanics Issues in Pulmonary Airways
Authors: Evrensel Cahit A. , Krumpe Peter E. , Olson Dan E. , Hammersley Jeffrey R. 
Published: December 2021

Abstract
Slowly travelling mucous, 2.4–5.5 mm/min, propelled by the beating action of cilia, is the main system to clear foreign substances from the pulmonary airways (Foster et al., 1980; Yeates, et al., 1981). Increased volume of mucous production and decreased mucociliary clearance may cause accumulation of mucous in the airway tree (Kim, 1997). Degree of airway obstruction due to access mucous and the effectiveness of the mucociliary clearance depends on rheology and quantity of mucous as well as activity of the cilia (King, 1998, Kim et al., 1997). The mucociliary system is complex and carefully regulated so as to maintain an optimal thickness of the serous fluid to facilitate the engagement of the beating cilia with the mucous layer (Yoneda et al., 1976). The depth of the serous layer is regulated by microtubules in the ciliated epithelial cell surfaces (Basbaum and Finkbeiner, 1990). The mucous layer apparently floats on its surface, either as a continuous sheet of overlapping layers and fibrous networks (Sturgess, 1977), or as a series of islands (Van As and Webster, 1974).
The Effects of Implantation Techniques and Vortex Shedding on Free Emboli Formation in Mechanical Heart Valves
Authors: Li Yanmei , Bluestein Danny 
Published: December 2021

Abstract
A numerical analysis of pulsatile turbulent flow was conducted past a St. Jude Medical MHV in the aortic position, to study the effects of valve implantation technique on the thromboembolic potential of the valve. The simulation focussed on the assumption that by altering the flow fields past the valves, the valve orientation and the suturing technique employed have a favorable or undesirable effect on the thromboembolic potential of the valve. It was demonstrated that the combination of a valve that is not aligned with the axis of the blood flow and subannularly sutured pledgets, produced accelerating jet flow through the valve orifices and a wider wake of periodic shed vortices in the valve’s leaflets wake. The existence of the shed vortices was confirmed by Digital Particle Image Velocimetry (DPIV). measurements. Platelets paths that exposed the platelets to the highest shear levels led them to entrapment within the shed vortices, indicating that the risk of cardioembolism will be enhance.
Cyclic and Residual Stresses Generated in the UHMWPE Component of Total Knee Replacements During the Walking Cycle
Authors: Natarajan Raghu N. 
Published: December 2021

Abstract
Fatigue due to cyclic stresses is one of the predominant failure modes seen in retrieved tibial polyethylene components. There is no clear understanding of the influence of knee kinematics on wear seen in retrieved samples. Magnitude, direction and location of the contact load at the tibial surface were taken from the measurement obtained from gait analysis of a patient with a total knee replacement and was input into a three dimensional finite element model of a tibial component. The analyses showed that stress fluctuations and stress reversals occur both on the surface and just below the surface in the posterior region of the component. Residual stresses were produced due to plastic deformation in the posterior contact region of the component.
Experimental and Finite Element Comparaison of Various Joint Fixation Designs
Authors: Patenaude O. , Shirazi-Adl A. , Dammak M. 
Published: December 2021

Abstract
The short- and long-term success of tibial cementless implants depends on the initial fixation stability provided primarily by posts and screws. Excessive relative motions at the bone-implant interface are known to inhibit bone ingrowth and, hence, biologic fixation. In this work, the performance of a number of fixation configurations under static and fatigue combined loads (i.e., compression plus shear) is investigated both experimentally and numerically. These results will permit both to compare different fixation types and to serve to validate a 3D finite element model that incorporates the measured nonlinear bone-implant friction and posts/screws pull-out tests. Once validated, the finite element model is also used to study the effect of different bone-implant friction models for porous coated posts and plate and of loading order of application on predictions.
On a Refined Finite Element Model of the Knee Joint
Authors: Moglo K. , Shirazi-Adl A. 
Published: December 2021

Abstract
A refined 3D elastostatic nonlinear finite element model was developed for the human knee joint in other to predict the passive global primary/coupled response and force transmission mechanism under various loads/movements and pathologic conditions. The joint geometry was based on an existing model (Bendjaballah et al., 1995) which was substantially refined in the articular cartilage and menisci regions as well as the articulating contact surfaces. The articular cartilage is subdivided into two layers along the depth allowing for the possibility to consider non homogeneity in mechanical propreties. The incremental response of the knee joint was evaluated under axial force of up to 780 N applied on the femur in full extension position. The global primary/coupled response, ligament forces as well as load transmission in medial/lateral plateaus through menisci and uncovered cartilage are analysed.