bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interphase Shear Strength of Titanium Metal Matrix Composites at Elevated Temperatures
Authors: Tamin M. N. , Osborne D. J. , Ghonem H. 
Published: July 2023

Abstract
A series of fiber pushout tests on thin-slice samples of a SCS-6/Timetal-21S composite were carried out to determine the load values at which partial and full debonding occurs. Finite element calculations of the stress field in the specimen were employed to assess the interphase strength of the composite as function of temperature. In these calculations, the semi-infinite thickness and the traction-free surface effects of the thin-slice samples on the corresponding stress field are considered. For each of these specimens, the distribution of shear stress along the fiber/matrix interface is determined in order to identify a region of stress localization which is taken in this study to be a measure of the interphase shear strength. This strength is then identified as the balance of forces at this localized field due to the traction-free surface of the composite section. Both contributions from process-induced residual stress and geometry-induced constraint of the traction-free surface to the strength are considered. The results of this study showed that the interphase shear strength decreases with an increase in temperature and processing-related residual stress contributes about 35 % to the interphase shear strength at room temperature. Furthermore, the interphase shear strength as calculated in this paper was found to be larger than that determined by considering uniformly distributed shear stress along a pushout fiber.
A Systematic Shear-Lag Approach for Analyzing the Failure Mechanisms in Ceramic Matrix Composites
Authors: Robertson David D. , Solti James P. , Mall Shankar 
Published: July 2023

Abstract
The present study examines various damage progression criteria to provide input to a shear-lag analysis of ceramic matrix composites (CMCs). The shear-lag as well as other analysis methods require matrix and fiber crack densities in addition to interfacial debond lengths as input to the analysis before the composite behavior can be approximated. The present approach examines criteria for damage progression consisting of a critical matrix strain energy to control matrix crack density, a Weibull-type damage progression scheme for fiber cracks, and ultimate interfacial shear stress to provide debond lengths. Fatigue modeling is also accomplished through an effective fiber pullout where the eventual failure in fatigue is modeled by the available elastic energy exceeding the work to fiber pullout.
Failure Analysis of Fiber Composites at Phase Interface
Authors: Edmiston Harry D. , Nomura Seiichi 
Published: July 2023

Abstract
Failure criteria of fiber reinforced composites expressed in terms of externally applied stresses are derived based on the interface stress distribution. The composite is modeled by a single inclusion surrounded by a matrix which possesses the properties of the composite. Using the Eshelby’s method and the self-consistent approximation, the interface stress can be derived analytically as a function of fiber and matrix properties and the fiber volume fraction. Using the proposed method, failure envelopes can be drawn that can properly reflect the effect of fiber shapes and anisotropy.
Fatigue Damage Evolution in a Short Fiber Reinforced Metal Matrix Composite
Authors: Canumalla Sridhar , Pangborn Robert N. 
Published: July 2023

Abstract
The micromechanisms of fatigue failure of a short, alumina-silicate fiber reinforced cast aluminum alloy (A356) are investigated in this study. The nature of damage evolution is studied by three complementary perspectives — i) monitoring of the mechanical response, ii) microscopy on the gage length and fracture surface, and iii) probing of the microstructural changes in the bulk nondestructively using acoustic emission. The damage evolution in the composite is driven by strain or fatigue cycles imposed on the specimen and is manifested as three distinct mechanisms: a) cracking at hollow shot particles early in the life, b) microcracking in the form of fracture of fibers oriented in the direction of the loading and splitting or decohesion at fiber/matrix interface of transversely oriented fibers, and c) void formation at fiber ends and other stress concentrations. The interaction among the different modes, which defines the evolution of microstructural damage, is described. A flow chart for the progression of damage is presented and the most important steps in the damage evolution are identified. Suggestions are made for improving fatigue performance by tailoring the microstructure of the composite.
Bridging Fiber Stress in Metal Matrix Composites: An Analytical Model
Authors: Ghonem H. 
Published: July 2023

Abstract
A modified shear-lag model suitable for describing bridging fiber stress in metal matrix composites subjected to fatigue loadings has been developed. The model considers the influence of the stress field in the fiber/matrix bonded zone as well as the ratio of the reversed to non-reversed sliding length within the interface debonding region of the fiber. Parameters representing the post-processing residual stress field and the load ratio of the applied loading cycle are also considered.
Electromagnetic Moving Armature Actuators for Active Vibration Control
Authors: Murray Bruce S. , Madden Richard , Berkman E. Frank 
Published: July 2023

Abstract
Shakers or vibration generators for the purpose of active vibration control should be extremely linear (i.e., low distortion), have small time lag, be capable of extended continuous reliable operation. Other attributes such as high force to weight ratio, compactness, ruggedness, ease of mounting, efficiency, and no special cooling are also desirable. Conventional shakers developed for laboratory or less demanding applications typically do not have all these attributes. We find that electromagnetic moving armature transducers can be designed to meet many of the above attributes better than other approaches. A 225 N (50 lbf) actuator example is used to present mechanical and electrical features that satisfy requirements of linearity, stability, size and force outputs. A larger 9 kN (2000 lbf) shaker example is used to illustrate the use of feedback control in the actuator to improve linearity even further and flatten frequency response.
Sound Scattering by a Submerged Shell Near the Sea Surface: Source and Receiver Close to the Shell
Authors: Huang H. , Gaunaurd G. C. 
Published: July 2023

Abstract
In previous work we studied the scattering of incident plane sound waves by a spherical elastic shell submerged in water which was arbitrarily near its free surface (H. Huang and G. C. Gaunaurd, Proceedings, 1995a). That study presented an exact solution of the problem valid for any shell depth beneath the free surface, and it used the method of images and the addition theorem for the spherical wave functions. We study the problem again, here, for cases in which the incident waves are now emitted from point sources anywhere in space beneath the free surface (i.e., close to the shell or to the free surface), and the receiver can pick up the scattered returns from arbitrary space positions. Among the many detailed results of the present study, it was found that for a point source near the shell, the scattered field is significantly different from that produced by a plane incident wave. [That field, in turn, is different from that returned in the elementary case of a shell in “free space”, i.e., away from any boundary.] A number of comparisons are shown as the shell and point-source take on positions that are: (1) at different depths beneath the free surface, and (2) at different distances from each other. For point sources more than twenty shell radii away from the shell, the far-field backscattered echo is not much different from that produced by a plane incident wave incident on the shell at the same depth. Our earlier solution can then be used in such cases. For point sources any closer to the shell, the present solution must be used. In such cases, as the shell and point source move further away from the free surface, together, a pattern of rapid oscillations is developed in the resulting form function which is the precise generator of the Lloyd’s mirror effect of elementary acoustics. The scattered field generated by an array of such point sources insonifying the shell, can also be obtained by a linear superposition of the exact solution given here.
Sound Radiation From a Finite Cylinder
Authors: Hu Qiang , Wu Sean F. 
Published: July 2023

Abstract
A formulation is derived which expresses the radiated acoustic pressure in terms of the tangential and normal components of the particle velocity at the surface of a vibrating object. The boundary condition at an impermeable surface requires that the normal component of the particle velocity be equal to that of the surface velocity, which is usually specified for acoustic radiation problem. The tangential component of the particle velocity is different from that of the surface velocity, but can be determined by using an intensity probe. In this paper, both the tangential and normal components of the particle velocity at the surface of a vibrating object are assumed specified. Hence the radiated acoustic pressure can be obtained by direct integrations of these known quantities over the surface. The formulation thus derived is validated on sound radiation from a right cylinder of finite length.
A New Methodology of Applying Measured Acceleration and Forces as Excitation on Powertrain Models for Noise Prediction
Authors: Vlahopoulos Nickolas , Stark Richard D. , Kargus Walter 
Published: July 2023

Abstract
Numerical methods can be used to compute the vibration of powertrain systems or components and the corresponding radiated noise. Specifically, the finite element method can be utilized in computing the structural vibration1, 2, 3. The structural response will constitute the boundary conditions for the boundary element method in computing the radiated noise4, 5, 6. In order to achieve reliable noise predictions it is important to have accurate information for the structural vibration since it is the source of the noise. In this work a new methodology for applying the loads on the structure is presented. It allows to exert as excitation a combination of measured accelerations, and forces or pressures. The innovative elements of this work are: (i) the methodology utilized in prescribing the acceleration at certain parts of the structure, (ii) integrating the vibration analysis within the acoustics software and creating a single process for computing the noise.
Effect of Expansion Chamber on the Resonance Frequency of Side Branches and Herschel-Quincke Tubes
Authors: Selamet Ahmet , Radavich Paul M. 
Published: July 2023

Abstract
Side branches connected to main ducts are known to create conditions susceptible to flow-acoustic coupling. A closed-end side branch resonator and a Herschel-Quincke tube, both coupled with an expansion chamber, are considered in the present study. The resonance frequency for these configurations is investigated as a function of the geometrical variations. The implications of the changes in resonance frequency are then discussed in relation to the flow-acoustic coupling.
Fuel Pump Vibration Measurements Using Laser Transducers
Authors: Wu Sean F. , Li Li , Rivin Eugene 
Published: July 2023

Abstract
This paper presents the results of vibration and noise measurements of Bosch fuel pumps by using laser transducers. Vibration of the pump consisted primarily of three components: radial, axial, and torsional. Results showed that radial vibration was predominant in the low frequency regime, torsional vibration in the mid to high frequency regime, and axial vibration in the high frequency regime. Pump noises were produced primarily by axial vibration, followed by torsional vibration. At high speeds, however, the tonal sound pressure levels of the harmonics due to torsional vibration became close to those of axial vibration, indicating that the two components of vibration were equally important. Contribution from radial vibration to the overall noise was negligible. Nevertheless, the amplitude of radial vibration was the highest and the vibration pattern of the pump housing was predominated by the first breathing mode of radial vibration. The causes of radial vibration could be attributable to the radial component of the force exerted on the pump housing by the fluid as it was sucked into the pump, and to the unbalancing forces of the shaft and impellers. The frequencies of the radial modes confirmed these assertions. The cause of axial vibration could be attributable to fluid/impeller interaction, which was also confirmed in the axial velocity spectrum. The causes of torsional vibration needed to be investigated further. The present hypothesis is that torsional vibration is due to moter-related excitations.
Case Study on Reducing Automotive Blower Rumble Noise
Authors: Humbad Niranjan G. , Hall Tim J. , Terry Joe , Hess Graham , Sohaney Rich C. 
Published: July 2023

Abstract
The climate control system is one of the major contributors to automobile interior noise, especially when the climate control blower operates at full speed. The air rush noise from the blower operated at high speed can be very annoying due to high noise levels and or due to discrete frequency tones or low frequency rumble. Every attempt is made to reduce the annoyance to improve customer satisfaction. This paper presents results of a case study related to source identification and resolution of low frequency rumble noise in a newly developed climate control system. Flow visualization, sound intensity and noise measurements were used to identify the noise source and subsequent changes to blower scroll in reducing the rumble noise in the bench study. Bench test noise reductions were verified on the vehicle. Subjective rating improvements of 2 (0–10 scale) were obtained on a new design compared to the baseline design.
Noise Reduction System for Telephones
Authors: Birman Chaim , Nasar Alan S. , Raichel Daniel R. 
Published: July 2023

Abstract
The goal of this project is to design a system that increases the intelligibility of voice transmission through a telephone or similar device when used in a noisy environment. The designed system incorporates an auxiliary microphone into the transmitter portion of an ordinary telephone handset. This microphone, strategically located so that it receives the ambient noise and virtually no speech from the user, develops a signal that becomes phase-inverted by the system.. The resultant signal is mixed with the signal from the primary microphone to produce a final signal that contains significantly less background noise than the original signal. The amended signal is then relayed to the telephone receiver in the same manner as in an ordinary telephone. This system has many applications in the design of telephones and two-way radios for use in noisy environments such as subway stations, city streets, aircraft cabins, truck cabs, construction sites, etc.
A Software for Acoustical Study and Design of Architectural Spaces
Authors: Narasimhan Mukundan , Raju P. K. 
Published: July 2023

Abstract
The study of architectural spaces and their acoustical characteristics is needed for a better understanding of the functional performance of an auditorium. Some of the methods used to analyze these spaces and their characteristics are scale model studies, wave analysis techniques and statistical methods. Computer aided analysis has become an important means for studying the propagation of sound and the distribution of acoustical energy. Keeping these aspects in view, a computer model using geometric ray analysis has been developed to study the temporal response of the reflection patterns of transient sound inside listening halls. The software has been implemented in C-Language. The program has built-in modules, which models both specular and diffuse reflections at the boundary. In the last module of the program, attempts have been made to design the reflectors inside the hall to avoid echoes. Using the developed software the change in the reflection pattern due to the presence of special reflectors has been studied with reference to the number of echo points, delay time and the Sound Pressure Level (SPL) difference between the straight ray and the reflected ray. Also, the variation in the difference of SPL and delaytime has been studied graphically with reference to the distance from the source. Experiments were conducted at an existing hall, and echograms obtained from these experiments are compared to the modelled results. Thus this software will be a very useful tool for acousticians designing auditorium.
Ultra High Speed Hydraulic Turbo Motor
Authors: Maeda Teruyuki 
Published: July 2023

Abstract
This paper describes an ultra high speed hydraulic turbo motor utilizing a negative damping flow force. The negative damping flow force is the main cause of the self-excited oscillation of a valve. The disk which was attached to the motor shaft was rotated with different loads which were determined by “ Eddy current method”. Rotational speed of the disk was measured by a non-contact revolution counter, and frequency characteristics of the sound pressure level were measured by a sound pressure level meter. We found that this ultra high speed improved hydraulic turbo motor had a 5 % higher rotational speed than the conventional one and it achieved 40,000 rpm under no load, 10 MPa, and 60 degree in C conditions. An theoretical analysis was conducted to explain these experimental results.
Study on the Dynamics of a Load Sensing System
Authors: Sakurai Yasuo , Takahashi Koji , Ikeo Shigeru 
Published: July 2023

Abstract
This paper deals with the dynamics of a load sensing system. The load sensing system is one of the most effective means to save energy. This kind of system, however, has an inherent demerit that it often falls into instability, which may be caused by the interaction between the load sensing mechanism and the load. It is important, therefore, to investigate the dynamic characteristics of a load sensing system. In the present paper, both experimental and simulation studies are performed. By making use of experimental results, a suitable mathematical model of the whole system is obtained. The effects of system parameters on the stability of the system are investigated using this model.
A Modified Orifice Flow Formula for Numerical Simulation of Fluid Power Systems
Authors: Ellman Asko , Piché Robert 
Published: July 2023

Abstract
The conventional turbulent orifice flow formula has an infinite derivative when the pressure drop is zero. This can cause ODE solvers to crash during numerical simulation of fluid power circuits. A two-regime orifice flow formula is proposed in which an empirical polynomial laminar flow formula is used for small pressure differences. The proposed formula has a smooth transition between laminar and turbulent regimes and does not have a singular derivative, and so is well-suited for accurate and trouble-free simulation.
Mapping of Large Scale Fluid Power System Simulations on a Distributed Memory Parallel Computer Using Genetic Algorithms
Authors: Pollmeier K. , Burrows C. R. , Edge K. A. 
Published: July 2023

Abstract
Parallel simulation of fluid power systems using the transmission-line modeling method offers the benefit of increased speed of execution, but requires the system model to be partitioned on to individual processors [Burton, 1994].
In this paper we address the automatic placement of component models on processors of a distributed memory parallel machine. A genetic algorithm is used to map the different processes onto several processors. The objective is to minimise the total processing time in order to achieve real time performance. For fine grained computation problems the communication time cannot be neglected, i.e. we consider the computation and the communication time of each task.
This mapping problem is a combinatorial optimization problem which can be reduced to the graph partitioning problem which is shown to be NP-complete. Combining genetic algorithms with heuristics leads to optimal or very good sub-optimal solutions. A hydraulic example circuit is partitioned in four and eight subsystems, respectively, and the simulation is implemented on a Transputer based platform. Using eight processors a speed up of 3.7 was achieved.
A Neuro-Fuzzy Control of an Electro-Hydraulic Fin Position Servo System
Authors: Lee Sang Yeal , Park Young Jun , Cho Hyung Suck 
Published: July 2023

Abstract
The electro-hydraulic servo systems have been frequently used in the fin position servo system of a missile because of their high power and good positioning capabilities. This paper presents a neuro-fuzzy control scheme for an electro-hydraulic fin position servo system. In this paper, we have explained a fuzzy control scheme which has multidimensional and asymmetrical membership functions, and we have designed a neuro-fuzzy controller which include parameters of the fuzzy logic controller. The effectiveness of this control scheme is verified by comparison with the conventional control algorithm through a series of simulation studies.
Weight Saving Plastic Design of Pressure Vessels
Authors: Porowski Janek S. , O’Donnell William J. , Reid Robert H. 
Published: July 2023

Abstract
Within the last two decades the use of elastic finite element analyses to demonstrate design compliance with the rules of the ASME Code has become a generally accepted engineering practice. Linearized stresses from these analyses are commonly used to evaluate Primary stresses. For redundant structures or complex structural details, the use of such analyses, instead of simple equilibrium models, often results in significant overconservatism. Direct use of finite element results is often preferred because equilibrium solutions are not unique and effective equilibrium models are not easily constructed for complex three-dimensional structures. However, finite element analyses include Secondary stresses, even for pressure, mechanical and shock loading.
For Primary stress evaluation the ASME Code allows the use of inelastic methods based on lower bound solutions and plastic analysis. For Primary stresses the Code requires equilibrium to be satisfied without violating the yield strength of the material. The use of finite element inelastic analysis to partition mechanically induced stresses into the Primary and Secondary categories was introduced by Porowski, O’Donnell et al. (1993). The latter provides a detailed discussion of the technical approach and the results for the axisymmetric junction between the plate and shell in a pressure vessel. This example was selected by the Session Organizer as a benchmark case to compare the efficiency of various analytical approaches presented at the Session. The authors have since used this approach to design more efficient structures. The practical application of this method to reduce the weight of complex redundant structures designed to meet Primary stress limits is described herein for a more complex three dimensional case. Plastic design utilizes the ability of actual materials to find the most efficient load distribution. A heat exchanger subjected to pressure, accelerations and nozzle external loads is evaluated as a practical example. The results of elastic analyses are compared with those obtained by inelastic analyses. It is shown that inelastic analyses can be used effectively to reduce the weight of structures using only modern PC’s for the engineering computations, as illustrated in this paper.