bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bending/Torsion Control of Wing Panels With Diagonal X-Actuators
Authors: Ye R. , Tzou H. S. 
Published: January 2022

Abstract
Simultaneous bending and torsion control of aircraft wings or helicopter blades can enhance the aerodynamic efficiency and flight maneuverability of aircraft and helicopters. Bending control of plates using parallel segmented piezoelectric actuators was demonstrated in the past. In this paper, a new X-actuator configuration of piezoelectric patches based on the same total actuator area is used to control both bending and torsion vibrations simultaneously. Control effectiveness of the X-actuator configuration is studied and compared with that of the original parallel line-actuator configuration. Finite element analysis data suggest that the new X-actuator configuration is effective to control of both bending and torsion modes.
Passive Voice Coil Feedback Control of Closed-Box Subwoofer Systems
Authors: Chen Cheng-Yi , Chiu George T.-C. , Peng Huei , Cheng Chi-Cheng 
Published: January 2022

Abstract
In this paper, the feasibility of using voice coil back-emf signal as feedback information for closed loop control was investigated. A dual voice coil closed-box subwoofer system is use to demonstrate the effectiveness of back-emf feedback control. A second order filter is developed to extract the velocity information from the coil back-emf signal. A PD controller is well suited for reducing the harmonic distortion and extending the subwoofer bass response. Experimental results verified that the proposed control scheme effectively extended the bass response of the subwoofer system by one octave and at the same time reduced harmonic distortion by more than 6 dB. The proposed feedback and control scheme can be easily implemented using inexpensive analog components, which can further reduce the cost and complexity of the system.
Passive Vibration Suppression of Beams Using Magnetomechanical Coating
Authors: Yen H.-Y. , Shen M.-H. Herman 
Published: January 2022

Abstract
This paper investigates the possibility of using magnetomechanical coating for enhancing high damping capacity on the high frequency structural response of beams. An analytical procedure is developed for modeling the dynamic behavior of beams coated with a plasma sprayed iron-chromium based coating. The effect of hysteresis nonlinear damping properties in terms of various stress or strain levels is investigated in the study. For the practical applications, in accordance with the proposed analytical procedure, a vibration formulation is presented. An extension to a continuous system is also discussed in this research.
Experimental Comparison of Delayed Resonator and PD Controlled Vibration Absorbers Using Electromagnetic Actuators
Authors: Elmali Hakan , Renzulli Mark , Olgac Nejat 
Published: January 2022

Abstract
The Delayed Resonator (DR) is a recent active vibration absorption technique which uses time delayed position feedback to generate ideal resonance in a passive vibration absorber. This can also be achieved using proportional and feedback (PD) control. In this paper, these two techniques are compared analytically and experimentally. It is also shown that actuator dynamics must be considered in order to determine the control parameters correctly. A theoretical development is presented towards this purpose. Experimental results show that both techniques are equally effective in vibration absorption.
On the Life Prediction and Accelerated Testing of Solder Joints
Authors: Qian Zhengfang , Liu Sheng 
Published: January 2022

Abstract
A critical review of the life prediction and accelerated testing of solder joints, including the role of constitutive modeling and the factors of accelerated testing, is presented in this paper. As a perfect example, Ford solder joint specimen was used to investigate accelerated testing factors under various accelerated testing conditions in terms of thermal fatigue life. Moreover, a typical PQFP (Plastic Quad Flat Pack) package was chosen to clarify the significance of fatigue life prediction in terms of different finite element models and unified and separated constitutive models. Thermal fatigue life prediction of flip chip packages with ball pitch sizes from 250 micron to 50 micron has been performed to illustrate underfill strengthening mechanisms and obtain an upper bound of accelerated testing factors, which can reduce testing time from three years to one week. Rate/temperature-dependent nonlinear properties of both eutectic solder and underfill FP4526 have been embedded in the ABAQUS finite element analysis for flip chip packages. All those examples enlighten key points addressed in this report.
A Linear Motor Driven Mini Tester and its Application to Thermal/Mechanical Fatigue Testing of Solder Joint Specimen
Authors: Lu Minfu , Qian Zhengfang , Liu Sheng , Wu Jianhau 
Published: January 2022

Abstract
A linear motor-driven mini fatigue tester has been developed at Wayne State University and reported in this paper with its application to mechanical fatigue testing of mini solder joint specimen. The tester, as the second generation of our DC motor-driven mini tester, is backlash free. Another advantage of the tester is its capability of high speed and long travel distance, making it powerful to the wide range of frequencies for mechanical fatigue testing, which is ideally suitable for accelerated fatigue testing. Several fatigue tests of solder joints have been performed by this mini fatigue tester. It is found that the kinematical hardening coexists with cyclic softening of solder joints, indicating early damage stage of solder fatigue. The testing results of a solder joint specimen designed by authors can also indicate both macro crack initiation and its propagation The voiding on failure surface of a solder ball specimen after fatigue is observed to support ductile damage characterization of solder joints.
Study of Nucleation of Diamond on Silicon Substrate by Ab-Initio Molecular Dynamics
Authors: Kayaba Tomoo , Inoue Akinori , Saka Masumi , Abé Hiroyuki 
Published: January 2022

Abstract
The diamond film has been drawn attention for the electronic devices used in higher temperature or the coating of cutting bytes used for the super hard aluminum because high quality diamond film has recently been able to be synthesized cheaply from the gas phase, using the CVD (Chemical Vapor Deposition) method. Diamond thin film has been confirmed to be connected to the substrate at the place around the nuclei grown at the beginning of deposition. In this paper, in order to solve fundamental process of the nucleation of the diamond based on quantum mechanics, ab-initio molecular dynamics simulation of the nucleation of the diamond on the silicon substrate is conducted. Only one carbon atom is used for the simulation aiming to show the fundamental process of the nucleation. A model that consists of a silicon substrate and a carbon atom is provided. The Car-Parrinello method is used for ab-initio molecular dynamics calculation. The action of the carbon atom on and in the silicon substrate in the simulation, and the situation of the combination between the silicon atoms in the substrate and the carbon atom are shown.
Wall Effects in Multiparticle Settling
Authors: Zhu Qinsheng , Clark Peter E. 
Published: January 2022

Abstract
Since many industrial processes involving suspended particles settling near walls, understanding the process is important. There has been a lot of work done on particle behavior near walls in Newtonian fluids, but not much has been reported for particles settling near walls in non-Newtonian fluids. There is almost no data available for multiparticle systems in either Newtonian or non-Newtonian fluids. In this study, we report the settling of single particle and two-particle systems at or near convex, concave and flat walls in both Newtonian and non-Newtonian fluids.
Spatial Concentration Variation in a Suspension Flow Through a Mold Cavity
Authors: Olivero Kristian A. , Altan M. Cengiz 
Published: January 2022

Abstract
The time dependent orientation field in a steady, Newtonian, Hele-Shaw flow containing slender particles is experimentally observed. The flow is created by injecting a suspension of corn syrup diluted with water containing fibers into a planar mold cavity with a three to one sudden contraction downstream. Time dependent orientation data is collected in the vicinity of the sudden contraction with a digital CCD camera connected to a PC based video capture card. Computerized image analysis is performed on each image to obtain the planar orientation of each fiber and the fiber concentration in that region of interest. Radial orientation distribution histograms are generated for different regions and time intervals to investigate time dependency of the orientation field and fiber volume fraction. Although the flow is steady, fiber concentration is found to fluctuate over time. Fiber concentration also varies considerably from region to region, with some regions containing fiber volume fractions much lower than the average volume fraction of the injected suspension.
Modelling and Control of a High Speed Hydrostatic Transmission
Authors: Njabeleke Ignatius A. , Pannett Richard F. , Chawdhry Pravir K. , Burrows Cliff R. 
Published: January 2022

Abstract
Fluid power systems are highly nonlinear, making the application of traditional linear feedback control techniques challenging. H∞ robust control techniques have been extensively studied recently but their practical feasibility in fluid power systems has not been convincingly demonstrated. In this paper, we consider the modelling and application of H∞ robust control to a hydrostatic transmission. We propose a dual mode controller which is extremely effective, delivering robust stability over the entire speed range and offering bumpless transfer, windup protection and multirate sampling at no extra cost, a factor which is crucial in digital implementation. The particular H∞ approach used is McFarlane and Glover’s loop shaping which, in addition to simplicity, admits a wider class of uncertainties than comparable schemes. We show that despite some challenges, H∞ loop shaping is able to satisfy a variety of control objectives and a successful application need not be of high order.
Implementation of Rosenbrock Integration Algorithm With Adaptive Step Size Control in Time-Domain Simulation of Fluid Power Systems
Authors: Käppi T. J. , Ellman A. U. , Piché R. 
Published: January 2022

Abstract
Numerical simulation models of fluid power systems typically have a large scale of different time constants and so can be considered as numerically stiff systems.
The Rosenbrock method is a differential equation integration algorithm with suitable accuracy and stability properties. In this paper the implementation of the Rosenbrock method as part of a time-domain fluid power system simulation package is presented.
Adaptive time step size control makes it possible to achieve an optimal computational effort with controllable integration error based on user-defined error tolerance.
Computation of examples show considerable improvement in accuracy and computational speed over the previously used integration method.
Design of Objective Functions for Optimization of Multi-Domain Systems
Authors: Andersson Johan , Pohl Jochen , Krus Petter 
Published: January 2022

Abstract
Engineering problems are often characterized by many conflicting objectives which span over several engineering domains. In this paper an approach to design of objective functions for engineering problems is presented.
Multi-domain systems can be characterized as complex systems which combine different fields of engineering. Here an aircraft landing gear is studied which is a true example of a multi-domain simulation problem due to the presence of mechanical, electrical and hydraulic sub systems. On this simulation model a non-gradient optimization strategy is applied where the formulation of the objective function is supported by the House of Quality method. The design of an objective function for optimization is in many cases a complex procedure involving a great amount of expertise. The House of Quality method is used here both to facilitate team activities and to elucidate the relation between system characteristics and system parameters.
Flow Analysis and Modeling of Shock Absorbers
Authors: Herr F. , Mallin T. , Lane J. , Roth S. 
Published: January 2022

Abstract
A Computational Fluid Dynamics (CFD) method, combined with a dynamic modeling technique were introduced to study the flow and performance of automotive hydraulic damper / shock absorbers. The flow characteristics of component obtained by using CFD was applied to dynamic modeling package to predict the damping force. The component CFD analysis showed unique features as far as flow part tern, discharge coefficients and pressure distribution for various shock absorber components. Dynamic damper model was constructed by using a commercial package Easy5 with flow information provided by CFD. A simple representation of the complicated design of shocks as a network of fixed and variable restrictions in series and parallel connected by compliant volumes of oil is suitable for capturing the dynamics important to vehicle handling simulations.
Leakage Behaviour of Four-Way Servovalve
Authors: Ellman Asko 
Published: January 2022

Abstract
The paper presents a model for a four-way servovalve which is based on nonlinear modelling of valves’ leakage behaviour. The model is identified according to measured flow rate at valve ports and pressure gain curve. The model can take into account some unsymmetry of the valve.
The model is verified in the case of a commercial servovalve.
Slipper Tipping Within an Axial-Piston Swash-Plate Type Hydrostatic Pump
Authors: Manring N. D. 
Published: January 2022

Abstract
In this paper, the dynamic characteristics of the slipper are investigated analytically for the purposes of predicting the phenomenon of slipper tipping without the use of laboratory techniques. In particular it is shown that slipper tipping result from the reciprocating inertia of the piston / slipper assembly as well as the centrifugal inertia of the slipper itself. Based upon a slipper tipping criterion, it is further shown that the worst tipping conditions occur at top dead center when the piston is moving from the discharge port to the intake port of the pump. In this region a combination of a pressure force and a force from the hold-down device may be used to guarantee successful operation of the pump. The required magnitude of these forces is shown in a closed form as a function of operating conditions which provides the design engineer with useful guidance for optimizing the overall design of the slipper and its hold-down device.
Vibration-Assisted Coupled Transport-Reaction Processing of Advanced Materials
Authors: Ilegbusi Olusegun J. 
Published: January 2022

Abstract
This paper describes a numerical study of the effect of vibration on two materials processes characterized by coupled transport-reaction phenomena. The first process is the production of SiC by the infiltration of porous carbon preform with molten silicon or silicon alloy, and subsequent chemical reaction between Si and C. The second process involves the burnout of organic binders from ceramic greenware. Transport equations are solved by the finite-domain numerical scheme for the conservation of mass, momentum, energy and species concentration in the porous media. A simple harmonic vibration is imposed as a transient source on the momentum equations. The growth rate of SiC and pressure rise in the ceramic greenware are predicted. The results demonstrate the potential of vibration to improve both materials processes. It is suggested that further systematic studies may allow the signatures of vibration to be used for characterization of the final products.
A New Analysis of Elastic Wave Resonance Scattering From an Elastic Cylinder
Authors: Rhee Huinam 
Published: January 2022

Abstract
The problem of elastic wave resonance scattering from elastic targets is discussed in this paper. A new resonance formalism to extract the elastic resonance information of the target from scattered elastic waves is introduced. The new resonance formalism is an extension of the works developed for acoustic wave scattering problems by the author. The classical resonance scattering theory (RST), which is usually being used for this type of problem, computes reasonable magnitude information of the resonances in each partial wave, but the phase behaves in somewhat irregular way, therefore, is not clearly explainable. The new method has been developed to obtain physically meaningful magnitude and phase of the resonances. As an example problem, elastic wave scattering from an infinitely-long elastic cylinder was analyzed by the proposed new method and compared with the previous studies by RST. In case of no mode conversion, both methods generate identical magnitude. However, the new method computes exact π radian phase shifts through resonances and anti-resonances while RST produces physically unexplainable phases. In case of mode conversion, even magnitudes are slightly different. The phase shifts through resonances and antiresonances obtained by the new method are not exactly π radians due to energy leak by mode conversion. But. the phases by the new method still show more reasonable and intuitive behavior than those by RST.
A Discrete Model of Turbulence Loading Function for Computation of Flow-Induced Vibration and Noise
Authors: Hwang Y. F. 
Published: January 2022

Abstract
This paper discusses a discrete representation of the spatially homogeneous and temporally stationary turbulence loading on a structure induced by low speed incompressible flow. In the classical random vibration theory involved with continuous structural systems, this forcing function is expressed as the space-time cross correlation function or its Fourier conjugate, the wavevector-frequency spectrum of the turbulent boundary layer (TBL) wall pressure. These functions cannot be applied directly to finite discrete systems, such as most finite-element structural models, because they contain a fine-scale oscillating component which represents the predominant pressure fluctuations convected with the flow. For example, at mid- and moderate high frequencies, this fluctuating length scale may become smaller than the mesh size of a discrete structure model. An approximated discrete forcing function model to ease this numerical difficulty is presented in this paper. The approximate forcing function model is verified by comparing the numerically calculated modal input force spectra to that obtained from exact analytical solutions. The numerical calculated values approach the exact solutions as the finite-element mesh size becomes smaller.
Marine Outboard Engine Exhaust System Design
Authors: Church Nathan J. 
Published: January 2022

Abstract
This paper describes a project in which the objective was to reduce the underwater sound levels produced by marine outboard engines while simultaneously maintaining acceptable above-water sound levels. The exhaust systems of different marine propulsion systems were studied, with emphasis placed on those of two-cycle outboard engines.
The acoustic performance of a typical 140 horsepower (104 kW) two-cycle outboard engine was measured and recorded. Modifications were then made to the engine’s exhaust system in an attempt to reduce the engine’s operational underwater sound levels. These modifications are discussed in detail. With the modifications complete, the engine’s acoustic performance was re-examined.
The modifications to the outboard’s exhaust system were found to reduce the engine’s overall underwater sound pressure levels by 77% at 1000 rpm. Above-water sound levels were found to be slightly increased at low engine speeds and decreased at high engine speeds.
Development and Evaluation of a Surface Acoustic Intensity Probe
Authors: Driesch Patricia L. , Koopmann Gary H. 
Published: January 2022

Abstract
The subject of this paper is the development of a new surface acoustic intensity probe that measures the sound power radiated by vibrating structures. Surface intensity methods have been a research subject for over two decades and provide a foundation for the probe design. The design combines two inexpensive components, an accelerometer and a microphone, both requiring careful calibration. A calibration device and method were developed to measure the frequency-dependent sensitivity of the microphone over a 160 to 1600 Hz frequency range. The calibrator mounts the probe on top of a piezoelectric actuator and together they are enclosed in a small air cavity. This calibration method provides a frequency-dependent phase correction for the microphone. For a low frequency performance evaluation, an array of probes measure sound power radiated from a clamped plate to within a few dB of a two-microphone intensity probe.
A Modal Synthesis Approach for Dynamic Response of Space Vehicle Systems
Authors: Sarigul-Klijn Nesrin 
Published: January 2022

Abstract
Prediction of the modal properties of large-scale space vehicle systems as a whole is a complicated process. Therefore the idea of developing the dynamic behavior of a large system from its components or subsystems is usually favored. This paper presents an improved modal synthesis approach that uses Gradient Adaptive Transfinite Elements (GATE) Family of finite elements to satisfy the interface compatibility conditions between the sub-systems. Numerical examples including a simulation of a three-axis stabilized spacecraft are presented showing the improvements obtained by using the proposed approach.
A Stochastic, Fuzzy, Neural Network for Unknown Dynamic Systems
Authors: Jing Zhongliang , Luo Albert C. J. , Tomizuka M. 
Published: January 2022

Abstract
A stochastic, fuzzy, neural network (SFNN) to model unknown nonlinear dynamic systems is developed. In this network, a non-singleton fuzzifier with Gaussian membership functions instead of the singleton fuzzifier in the fuzzy logic is introduced. Based on these membership functions, an online supervised parameter learning algorithm of the SFNN is proposed to overcome the local minimum of learning process in current neural networks, and an off-line algorithm for the structure learning of the SFNN is presented to reduce the amount of computation of the SFNN. This new network provides a universal approximator and it is also applicable to stochastic control and decision systems and the identification of chaos in nonlinear systems.
A New Simplified Model of Shrouded Blisk and its Dynamic Behaviour
Authors: Li Lin , Baumgartner Manfred 
Published: January 2022

Abstract
A model of a cyclic two-dimensional spring-mass-damper substructure of a bladed disc is presented. The method considers the shroud interlock angle and the direction of the blade motion. This is an improvement of the cyclic 1 DOF substructure modelling. The equations of motion for the mechanical replacement system are presented in the paper. The dynamic behaviour of the system especially the effect of the interlock angle are investigated.