bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Lumbar Facet Capsular Ligament Strains Due to Joint Pressure and Residual Strain
Authors: Gacek Elizabeth , Ellingson Arin M. , Barocas Victor H. 
Published: March 2022

Abstract
The lumbar facet capsular ligament, which surrounds and limits the motion of each facet joint, is mechanically significant and has been the subject of multiple previous mechanical characterization studies. Those studies, however, were performed on isolated tissue samples and could not assess the ligament's mechanical state in vivo, where attachment to rigid bone and joint pressure forces lead to non-zero strain even when the spine is unloaded. In this work, we quantified these two effects using cadaveric lumbar spines (5 spines, 20 total facet joints harvested from L2-L5). The effect of joint pressure was measured by injecting saline into the joint space and tracking 3-D capsule surface motion, and prestrain due to attachment was measured by dissecting a large tissue section from the bone and tracking motion between the on-bone and free states. We measured joint pressures of roughly 15-40kPa and local 1st principal strains of up to 25-50% for 0.3mL saline injected into the joint space. The largest stretches were in the bone-to-bone direction in regions spanning the joint space. When the ligament was released from the vertebrae, it shrank by 4-5% on average, with local maximum (negative) principal strains of up to 30%. Based on these measurements and previous tests on isolated lumbar facet capsular ligaments, we conclude that the facet capsular ligament's normal in vivo state is in tension, and that the collagen in the ligament is likely uncrimped even when the spine is unloaded.
A Retractable Six-Prong Laparoscopic Grasper for Laparoscopic Myomectomy
Authors: Butters Brenden , Fernández-Galiana Álvaro , Wollin Daniel , Traverso Giovanni , Slocum Alexander , Petrozza John 
Published: March 2022

Abstract
The fixation and manipulation of fibroids during laparoscopic myomectomy is a persistent issue for gynecologic surgeons. In this paper, we present a laparoscopic grasper that, through a sheath-based deployment mechanism, opens into a larger multitoothed grasper within the patient and collapses back for removal. Due to the increased number of contact points with the tumor, the expanded grasper allows for reliable fixation, aiding in manipulation during excision. We describe the nature-inspired design of the grasper from a physical foundation, establish the design theory and practical issues, and present manufacturing and testing of a full-scale 5 mm grasper. The unit was tested on synthetic fibroid models and was able to sustain a 50% higher load before tearing than a common single-tooth tenaculum. This development not only promises to improve fibroid fixation in myomectomy but also its design could be adapted to aid in the fixation of other difficult tissues in laparoscopic surgery.
Numerical Wear Models for Knock-On Chisels in Real Operating Conditions
Authors: Vrublevskyi Oleksandr , Napiórkowski Jerzy , Gonera Jarosław , Tarasiuk Wojciech 
Published: March 2022

Abstract
Recently, attempts have been made to use 3D scanning to evaluate the wear process of working elements. This paper proposes a new approach to develop a wear model based on an in-depth analysis of changes in the shape of a working component of an agricultural machine. For this purpose, chisels of plowshares used under varied soil conditions were analyzed. Numerical models of worn-out working parts created using 3D scanning were the basis for developing the model. Based on the hypothesis of correlative dependence between changes in wear phenomena and the direction normal to the working surface, a new index was obtained: the shape degradation coefficient. The relationship between the shape degradation coefficient and changes in the profile of the working surface was examined to demonstrate the effectiveness of the application of the new wear model compared to field measurements. The results of work surface microstructure tests also confirm the accuracy of the wear presentation concept proposed in this paper.
Design for Manufacturability and Concurrent Engineering in Integrated Product Development Process
Authors: Sun W. , Lau A. C. W. 
Published: March 2022

Abstract
With recent advancements in computer-aided technologies, integrated CAD/CAE/CAM, rapid prototyping and manufacturing, the paradigm of concurrent engineering has been proven as an effective approach for new product development. This approach can reduce product developing time and cost, improve product quality and enhance product competitiveness. This presentation uses an actual rapid product realization case study to highlight how design for manufacturability and concurrent engineering were implemented into an agile product development process by using an integrated design, analysis, and manufacturing approach and applying design for manufacturability for cost and manufacturing processing analyses. The case study shows how modern design and manufacturing technologies realize the dream of an inventor to rapidly develop a product with potential market success.
Case-Based Generation of Design Concepts
Authors: Zhao Wang , El-Gizawy A. Sherif 
Published: March 2022

Abstract
Knowledge accumulated from past design experience would help the design engineer in one of two ways: relating the functional requirements of the artifact being designed to parts, assemblies, and systems, or assembling independent parts, assemblies, or systems to achieve the desired functional requirements. In the natural thinking process of most of the engineering designs, those parts, assemblies, systems are associated with some typical design cases.
In the perspective of domain knowledge transformation (DKT), the process of case-based reasoning (CBR) is a knowledge state transformation from old design cases to a new design solution. This paper attempts to highlight CBR in generating design concepts (solutions) by knowledge-based design system. Starting with a brief introduction of CBR, the discussions focus on the major challenges of deploying the CBR paradigm in the conceptual design of mechanical systems, viz. how to describe cases, represent and retrieve past cases to be used as candidates of a solution to a new design problem, and so forth. These issues are discussed particularly in the light of the design of positioning systems. A case study is presented to illustrate CBR in generating design solutions.
Determination of Tolerance Distribution of a Mechanical Assembly Through Cost Minimization
Authors: Basaly Nadia A. 
Published: March 2022

Abstract
Manufacturing of parts which exactly meet engineering drawings dimensions for experience is known to be impossible. Drawings specify ideal geometry of the form, size, and location for the component features and surfaces. In addition to definition of the ideal geometry’s, the designer defines some region of tolerability around these ideal dimensions realizing that the nature variation exists when producing a part. The objective of this paper is to conduct a tolerance distribution of a mechanical assembly through cost minimization that can be accomplished through consideration of both assembly stack-up and manufacturing cost minimization. The analysis is accomplished by defining the components of the assembly as random variables and their associated tolerances as the standard deviation of the part dimension. This probabilistic approach allows trade-off between the fit of the assembly and the component tolerances as opposed to the typically practiced worst case analysis. The approach is comprised of a three step iterative process. First, tolerance analysis is accomplished to ascertain the assembly fit function based on the desired yield. Secondly, a probability test is completed on the assembly to identify its manufacturing credibility based on the desired yield. Finally, an optimally test is accomplished based on a given cost model to identify the optimum tolerance distribution.
In-Line Skating and Skateboarding: Injury Patterns and Prevention
Authors: Tudor Andrew H. , Fuller Luanda J. 
Published: March 2022

Abstract
The increased popularity of in-line skating and skateboarding has led to an increase of injuries typical to these sports. Protective equipment for skaters and skateboarders has not yet reached the level of sophistication of sports equipment used for more traditional recreational activities. This article reviews the injury patterns associated with in-line skates and skateboards, and analyzes the current status of protective equipment and equipment standards for these recreations.
Investigation of Impulsively-Started Flow Around Side-by-Side Circular Cylinders: Application of Particle Image Velocimetry
Authors: Sumner David , Price Stuart J. , Païdoussis Michael P. 
Published: March 2022

Abstract
The impulsively-started flow field for two and three circular cylinders of equal diameter arranged side-by-side has been investigated using particle image velocimetry (PIV), over a transverse pitch ratio range of T/D = 1.0 to 3.0, and for Reynolds numbers from Re = 1500 to 3000. The PIV technique was used to obtain a time history of the instantaneous in-plane vorticity field from the moment of impulsive start, from which the development of the flow was studied. Measurements of vortex strength and vortex position relative to the cylinders were obtained from these data. Two and three cylinder configurations of T/D = 1.0 were found to exhibit a cursory degree of similarity to a single, isolated impulsively-started circular cylinder. Side-by-side configurations of T/D &gt; 1.0 were dominated by the strong gap flow(s) between the cylinders, the vortices generated alongside the gap flow(s), and the formation of a single counter-rotating vortex pair in the far-wake.
Estimation of an Improved Technique for Measuring a Near Wake Flow Field of a Bluff Body With a Parallel Triple-Wire Probe
Authors: Waka R. , Suzuki T. , Ochiai Y. , Watanabe T. 
Published: March 2022

Abstract
An improved technique using a hot-wire probe is proposed in order to obtain a more reliable velocity vector field which is less strongly influenced by the prong wake of the hot-wire probe.
In the present experiment, a parallel triple hot-wire probe was used and the velocity vectors were determined by a phase-averaging technique and the general response equations. The hot-wire probe was set not only parallel to (conventional technique) but also obliquely to the coming flow direction (improved technique). The improved technique was applied to the near wake flow field of a two-dimensional square-section cylinder.
As a result of the experiment, it was confirmed that the improved technique proposed here was useful for improving the experimental reliability for the velocity vector field of the square cylinder, except for the base region, compared with that measured by the conventional technique.
Flow-Induced Vibration of a Tube Array in the Inlet Region of a High Performance Steam Generator: Part 2 — Unstable Vibration and Chaos
Authors: Iwase Toshihiko , Sunami Takeshi , Matsutani Kazuhiko , Nakamura Tomomichi , Mureithi Njuki W. , Tsuge Ayao , Kasahara Jiro , Tomomatsu Ken-ichi , Takaba Osamu 
Published: March 2022

Abstract
The vibration of a tube array in the entrance region of a high performance steam generator, which is caused by the flow of the coolant fluid, has been shown to be random and having small amplitudes in Part 1 of this series. In this second part, the results of tests with modified tube boundary conditions are presented. Fluidelastic instability leads to chaotic vibration. All of the flexible tubes are at the extremities of the tube array, where the fluid-flow enters or exits the array. Even in this position the tube instability can be predicted by a Connors’ type criterion. Chaotic vibration occurs because the tubes have small gaps at the intermediate supports along the tube-span. A fractal dimensional analysis shows good coincidence with physical explanation of the phenomenon based on observation.
Broadband and Tonal Noise of Flow Excited Cavities
Authors: Bruggeman J. C. , Looijmans K. N. H. , Golliard J. 
Published: March 2022

Abstract
Noise generation by low Mach number flow over a cavity is investigated. Prediction models for broadband noise and for tonal noise are compared with experimental data. The prediction model for broadband noise is based on the wavenumber-frequency spectrum of pressure fluctuations under a turbulent boundary layer. In the prediction method for tonal noise, the self-sustained flow oscillations in the cavity opening are represented by periodic shedding of discrete vortices. The shape of the frequency spectrum of the broadband noise data agrees with the prediction but the amplitude of the data is 20–25 dB higher than the predicted values. The Strouhal numbers for tonal noise are well predicted by the present model. It is shown that self-sustained oscillations occur in the experiment for conditions where linearized stability theory predicts that shear layer oscillations will not grow.
Energy Flow Analysis of Flow-Excited Beams and Plates
Authors: Han F. , Bernhard R. J. , Mongeau L. 
Published: March 2022

Abstract
Two methods for calculating the power density input to structures excited by turbulent flow were developed and used to predict the average response of the structure. The input power density was calculated using the cross-spectral density of the random fluctuating pressure loading on the structure. The energy response of structures excited by distributed loading was obtained using the energy flow analysis method. Both methods for calculating the input power density and the method for calculating the energy density response were verified for beams and plates using classical modal analysis.
Non-Viscometric Flows of Viscoelastic Fluids in Round Tubes Driven by Transversal Boundary Waves
Authors: Siginer Dennis A. , Li Yunling 
Published: March 2022

Abstract
The unsteady transversal flow field in the tube flow of a memory integral fluid of order type driven by rotational boundary waves is investigated. A perturbation in terms of the amplitude of the sinusoidal boundary waves is used. Qualitative conclusions are independent of the explicit forms of the constitutive functions. Quantitative results are obtained by assuming Maxwell type of behavior for the latter. It is shown that transversal steady flows is a possibility if several rotational waves with frequencies in a certain ratio are imposed on the boundary. As a result helical steady flows may be possible in the longitudinal direction in a round tube. A parametrical study of the oscillating transversal field is presented for highly elastic and shear thinning liquids.
Active Control of Cantilevered Pipes Conveying Fluid With Constraints on Input Energy
Authors: Doki Hitoshi , Hiramoto Kazuhiko , Skelton Robert E. 
Published: March 2022

Abstract
This paper deals with the stabilization of flutter phenomena of cantilevered pipes conveying fluid with constraints on input energy for control. The controller in this study is designed by using an algorithm which iteratively tunes the weighting matrix of the quadratic performance index in LQG problem. This controller design method takes the performance of the actuator into consideration. The theoretical and experimental results show that the effectiveness of the controller in stabilizing the flutter phenomena of cantilevered pipes conveying fluid varies according to the input variance constraints, i.e., the difference in the dynamic range of an actuator. Furthermore, the critical flow velocity at instability of the pipe can be estimated by the method stated in this paper, where the system loses its stability because of the restriction of control force produced by an actuator.
Evaluation of Fluidelastic Forces in Axial Flow With Simplified Computational Fluid Dynamics
Authors: Kichenin J. 
Published: March 2022

Abstract
The nuclear industry is demanding low cost methods to prevent flow induced vibrations, which are a major cause of wear and damage of components such as core control bars.
An original model to compute the fluidelastic forces in axial flow is introduced in order to predict flutter. To carry on the calculation, a modal shape displacement is assumed and the Navier-Stokes equations are linearized, simplified and solved assuming the superposition of two independent velocity fields:
• V→0(M) is the steady-state flow along the fixed body, computed with a turbulent k-ϵ model;
• u→(M,t) is the potential flow associated with the vibration in “still” fluid.
The case of an uniform annulus is treated first, then a step variation is considered and finally the approach is extended to any parallel flow configuration. This method enables to compute the added mass, damping and stiffness coefficients and the structure in-flow eigenvectors without new algorithm.
Comparisons with the works of Païdoussis (1973), Gibert (1988), Perotin and Granger (1992) are presented here. Some rigid body laboratory tests are discussed and a satisfactory agreement between the predicted damping coefficient, the flutter occurrence and the experimental results is achieved.
Analysis of Acoustic Resonant Vibration Having a Mutual Exciting Mechanism
Authors: Tanaka Hiroki , Matuzoe Jungo , Tanaka Kazuhiro , Shimizu Fumio 
Published: March 2022

Abstract
A duct containing a tube bundle undergoes acoustic resonant vibration. It is considered that the acoustic vibration is a kind of forced vibration by means of Karman vortex. However, it will be more reasonable to think that the vibration is a kind of mutual excited vibration, because fluid force excites sound pressure and the sound pressure also excite the fluid force. Equation of motion of sound pressure was derived from the mutual excited mechanism. Solution of the equation revealed that the imaginary part of the fluid dynamic force on the tube bundle supply the energy of sound and on the other hand, radiation of sound consumes the energy. By comparing the supplying and consuming energies, it became possible to calculate a boundary where acoustic resonant vibration will occur.
Damping of Tube Bundles in Two-Phase Air-Water Cross-Flow
Authors: Baj F. , Payen T. , de Langre E. 
Published: March 2022

Abstract
The investigation of damping in two-phase air-water cross-flow is discussed in this paper. A design guideline had been proposed by Pettigrew et al. (1994). In this paper, new set of air-water experiments is analysed. It is observed that the above guideline is too conservative and that flow velocity needs to be used to account for the scatter of data. Then, a new reduction of data is proposed and dependence of fluid damping with reduced velocity is investigated.
Flow-Induced Oscillations of a Butterfly-Valve: Prediction of the Frequency Behaviour
Authors: Hirt Felix , Iten Roger , Ziada Samir 
Published: March 2022

Abstract
The present valve design consists of two leaflets that are freely movable around a pivot and arranged within an orifice. At the open position the leaflets form a slight divergence angle. The flow patterns at low Reynolds number generated by such a design are associated with leading-edge stall and vortex-shedding from the leaflets. The present investigation is directed to a better understanding of the nature of this flow. In particular the effect of leading-edge stall on the angular oscillation behaviour of a single leaflet is of interest. For this purpose the leaflet momentum has been described in terms of a simple nonlinear hydrodynamic model which takes into account the direction of the gravitational vector. Based on that model the frequency behaviour was investigated numerically in parameter space. The effect of the flow speed on the oscillatory leaflet motion is treated as quasi-steady, that means for small Strouhal numbers Sh ≪ 1. The preliminary results reveal a strong dependence of the oscillation frequency on the amplitude and on the direction of the gravitational field vector. On the basis of a perturbation analysis an expression relating frequency and amplitude was found.
Experimental Characterization of Centrifugal Pumps as an Acoustic Source at the Blade-Passing Frequency
Authors: Zbroja Stan , Rzentkowski Grzegorz (Greg) 
Published: March 2022

Abstract
In this paper, we formulate an experimental method to examine the pump acoustic characteristics and report the test data. First, we assess the resonance effects in the test loop by calculating the acoustic impedance and reflection coefficient at the pump ports from local pressure field measurements. Next, we decompose the measured signal into the components associated with pump action and loop acoustics with the use of a simple pump model based on linear superposition of pressure wave transmission and excitation.
We apply this technique to examine the acoustics of a single-stage, double-volute centrifugal pump. We estimate the strength of source variables at the blade-passing frequency and establish the pump characteristics as an acoustic source. The results indicate that the source variables are nearly free of acoustic resonance effects in the test loop. The pump characteristics, however, depend on the location of pump ports and loop acoustics; that is, a given pump may act either as a pressure or as a velocity source.
Serial and Parallel Fast-Floquet Analyses in Rotorcraft Aeroelasticity
Authors: Subramanian S. , Venkataratnam S. , Gaonkar G. H. 
Published: March 2022

Abstract
Rotorcraft stability investigation involves a nonlinear trim analysis for the control inputs and periodic responses, and, as a follow-up, a linearized stability analysis for the Floquet transition matrix (FTM), and its eigenvalues and eigenvectors. The trim analysis is based on a shooting method with damped Newton iteration, which gives the FTM as a byproduct, and the eigenanalysis on the QR method; the corresponding trim and stability analyses are collectively referred to as the Floquet analysis. A rotor with Q blades that are identical and equally spaced has Q planes of symmetry. Exploiting this symmetry, the fast-Floquet analysis, in principle, reduces the run time and frequency indeterminacy of the conventional Floquet analysis by a factor of Q. It is implemented on serial computers and on all three types of mainstream parallel-computing hardware: SIMD and MIMD computers, and a distributed computing system of networked workstations; large models with hundreds of states are treated. A comprehensive database is presented on computational reliability such as the eigenvalue condition number and on parallel performance such as the speedup and efficiency, which show, respectively, how fast a job can be completed with a set of processors and how well their idle times are minimized. Despite the Q-fold reduction, the serial run time is excessive and grows between quadratically and cubically with the number of states. By contrast, the parallel run time can be reduced dramatically and its growth can be controlled by a judicious combination of speedup and efficiency. Moreover, the parallel implementation on a distributed computing system is as routine as the serial implementation.
Modeling and Aeroelasticity of Advanced Aircraft Wings Carrying External Stores
Authors: Gern Frank H. , Librescu Liviu 
Published: March 2022

Abstract
In order to study the effects of wing mounted stores upon the aeroelasticity of advanced aircraft wings, a comprehensive structural model has been developed. The wing structure is idealized as a laminated composite plate thus leading to the concept of a shear deformable plate-beam model. Free body motions at the wing root are induced by the motion of the airframe in pitching, plunging, and rolling. Non-classical effects like warping inhibition and transverse shear flexibility are included in the structural model. The relevant equations of motion as well as the appropriate boundary conditions are obtained via Hamilton’s variational principle and application of generalized function theory in order to exactly consider the spanwise location and properties of the attached stores. Numerical predictions for divergence behavior and static aeroelastic response of the system using extended Galerkin’s Method are supplied.