bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sealing Fuji Prescale pressure sensitive film for protection against fluid damage: the effect on its response
Authors: Liggins A.B. , Surry K. , Finlay J.B. 
Published: October 2008

AbstractFuji Prescale pressure sensitive film will record pressures as a characteristic pink stain; the optical density response of these stains can be calibrated to allow subsequent conversion into full field pressure data. Due to its ease of use, Fujifilm has been employed extensively within animal joints. For this application, the potential disruption to the stain producing mechanism posed by the presence of joint fluids has led to the widespread use of fluid proof materials, within which the Fujifilm is protected; however, little data have been presented on the effect of protective materials on the subsequent stain response. This paper presents a quantitative assessment of the mean optical density responses of both protected film and a control group of unprotected film; the first group consisted of Fujifilm sealed between two layers of a readily available self‐adhesive material, forming sealed packets. The results indicated significant differences between groups (p<0.05); however, the effect of these differences is dependent on the method used to produce pressure data. Qualitative observations indicated that sealing reduced stain uniformity; preliminary qualitative observations regarding data manipulation methods to overcome this phenomenon are presented. Consequently, this work indicates the importance of validating methods for protecting Fuji film from fluid damage and their associated methods of data manipulation.
Application of the shadow optical method to fatigue and crack closure studies
Authors: Hermann R. , Bull C. 
Published: October 2008

AbstractIn this paper it will be shown that crack closure and related crack shielding mechanisms can be studied successfully by applying the shadow optical method, also known as the method of caustics. It is shown that at least one mechanism ‐ plasticity induced crack closure ‐ can be identified and determined from measurements of the transverse diameter of the caustic in the crack tip region. For given fatigue conditions at which crack closure occurs, several experiments have been performed to investigate the effectiveness of the crack opening in a typical fatigue cycle.Two different methods of closure determination have been used. A comparison is made between one of the most currently used methods of back face strain (BFS) compliance measurement and the shadow optical method (SOM). The underlying features of these two experimental techniques provide the key to finding the extent of the load in the fatigue cycles over which the crack is actually open. This redefines the value of Kmin and the meaning of ΔK. The driving force, ΔKeff is shown to be reduced in or near the fatigue threshold of the alloy, because crack closure is most effective in this part of fatigue loading. The introduction of SOM to fatigue crack closure provides a suitable alternative for finding the effective part of the stress intensity range between the minimum and maximum loads. Conclusions drawn from this work were that in addition to determining that part of the fatigue cycle over which the crack is actually open, the shadow optical method allowed an accurate interpretation of the entire fatigue cycle between Kmax and Kmin
A simple finite element for beams on elastic foundations
Authors: Wasti S. Tanvir , Senkaya Ender 
Published: October 2008

AbstractA simple “routine” beam on elastic foundation finite element using a polynomial displacement function has been developed which yields acceptably accurate deflection, shear and bending moment values for prismatic or non‐prismatic beams of elastic material resting on foundations with varying or nonlinear subgrade reactions. Limited extension of the formulation to an “exact” finite element using the exact displacement function of a beam on elastic foundation has also been carried out. The subgrade is represented by a non‐homogeneous solid medium to include nonlinear parameters if required. The iterative solution is extended to cases where the beam may uplift because the foundation is a no tension material. The model is also suitable for calculating the elastic deflections, membrane. and bending stress resultants for axisymmetrically loaded variable thickness shells of revolution. A computer program called FEBEF [finite element: beam on elastic foundation] incorporating the routine finite element has been prepared for the solution of beams on elastic foundations and axi symmetrically loaded shells of revolution.
Determination of necking zone using laser speckle
Authors: Tay C.J. , Shang H.M. , Kang B.L. 
Published: October 2008

AbstractThis paper presents a whole field laser speckle method for the measurement of the necking zone on the surface of metallic specimens. The method employs an expanded laser beam to illuminate the test object. Diffracted images are recorded on a high resolution photographic film and subsequently filtered using point wise filtering. The intensity of the diffracted halo is measured with a photo‐sensor and the intensity distribution on the specimen yields information on the necking zone of the test object. The technique is applied to aflat tensile specimen with two circular notches at the central portion. Measured necking zone is compared with results obtained by other conventional methods.
Verification of the duplex gauge using variable strains and temperatures
Authors: Cappa P. , Sciuto S.A. , McConnell K. , Zachary L. 
Published: October 2008

AbstractFour steel specimens were equipped with “duplex nances”, a recently proposed transducer based on two different electrical resistance strain gauges, capable of correcting the effects induced by temperature. The examined innovative transducer, in comparison with traditional strain measuring systems, has the advantage of utilising two strain gauge channels of the same type, which significantly simplifies automatic measuring systems. The specimens were subjected to temperature and strain field variations in the ranges of=30–150°Cand=100–700μm/m respectively The temperature and strain values obtained from the duplex gauges were compared with those measured by means of traditional methodology, i.e. a strain gauge and a thermocouple.
Local stiffening effect of ‘double deck1 bending strain gauges: part 2
Authors: Chen J.F. , She K.M. , Rotter J.M. , Ooi J.Y. 
Published: October 2008

AbstractIn stress measurement where it is difficult or impossible to access the inside surface of the structure, “double deck” (DD) or “sandwich” bending strain gauges can be used to measure both the membrane and bending strains. A DD gauge consists of a pair of constituent foil gauges which are bonded on the upper and lower surfaces of a plastic base or filling. It is mounted on the external surface of the test specimen to measure the external surface strain, and by extrapolation, the internal surface strain of the. specimen. The. sensitivity of the DD bending gauge increases when the separation between the pair of constituent foil gauges increases. However, this also increases the stiffness of the whole gauge. If the stiffness of the DD gauge is significant compared with that of the plate to which it is attached, the presence of the gauge may cause significant changes in local stiffness and result in errors of strain interpretation. This study is presented in two papers. Part I, appeared in the Feburary 1996 issue of Strain, presented an approximate analytical solution for the local stiffening effect of a DD gauge, and quantifies the errors in the strain measurement. Part 2 (this paper) presents the verification of the. solution using a three‐dimensional finite element calculation, a parametric study and a correction method that can be applied easily. The extrapolation errors due to the stiffening effect and random reading noises are also explored. The figure and equation numbers in this part are continuedfrom Part 1, but the reference numbering is specific to Part 2.
Curvature contours of flexed plates by a multiple illumination moiré shearing interferometer
Authors: Subramanian G. , Subramanian A. 
Published: October 2008

AbstractA new moiré method is proposed to map partial slope, partial curvature and twist curvature contours of laterally loaded specularly reflecting plate models. Converging HeNe laser light is diffracted by a lens plane cross grating, different combinations of orders are selectively permitted through the Fourier transform plane and collimated to illuminate the plate model. This technique eliminates the difficulties involved in Fourier filtering in the imaging optics, thereby extending the reflection moiré’ interferomelry to general plate structures and loading. The slope contours are obtained still by double exposure.
Bending analysis of a finite beam on a reinforced halfplane
Authors: Chandrashekhara K. , Antony S. Joseph , Mondal Debashish 
Published: October 2008

AbstractThis paper deals with an experimental study, using the photoelastic method, on the bending analysis of a centrally loaded finite free‐free beam resting on a partly reinforced (horizontally) elastic halfplane. In the experimental study the interface between the beam and partly reinforced halfplane has been made both frictionless and fully bonded. An experimental‐numerical hybrid method, developed earlier by the authors has been used to determine the contact pressure distribution. The contact pressure distribution thus obtained has been compared with the results obtained using an analytical‐numerical procedure in which two different modellings have been used for the reinforced region viz., (i) equivalent orthotropic (composite approach); and (ii) layered system (discrete approach). Results of contact pressure distribution as well as bending stress distribution in the beam have been presented for several cases. The experimental procedure presented here is easy to apply to such complex practical problems and could be of interest to design engineers.
Case study of safe lowering of an in service gas pipeline
Authors: Khadakkar Anil G. , Sankar K. Ravi , Rathinam P. , Narayanan R. , Rao S. P. , Popli J. K. 
Published: October 2008

AbstractThis paper describes an experimental investigation carried out involving instrumentation, measurement and monitoring of stresses in a large diameter gas pipeline during its lowering operations. It also highlights the ingenious techniques developed and adopted to overcome the difficulties pertaining to long leadwires, measurement of existing strains on the curved surface of a pipeline and protection of strain gauge installations. These novel methods were used to ensure smooth and proper functioning of strain gauge instrumentation even under the severe field conditions at site for more than two weeks, till the lowering operations and pipeline monitoring was successfully completed.
Measurement of cheek/tooth forces during speech production
Authors: Cama G. , Cappa P. , Kaitsas V. , Mastrantonio F. , Scluto S.A. 
Published: October 2008

AbstractThis paper deals with the “in vivo” evaluation of the forces exerted by perioral muscles on dental arches and describes the relationship between these loads and the acoustic emission, during speech production. To carry out the research two miniaturised load cells were placed on the upper incisors' vestibular surface of 12 patients (6 male, 6 female age ranging from 19 to 25 years) to monitor the contact forces generated during the pronunciation of three phonemes containing labio‐dental sounds. The acoustic pressure was gathered by means of a capacitive microphone. From the obtained results it is shown that some values of the force applied during speaking are of significance in corrective orthodontics; in fact, the maxima of the recorded values were approximately 2.7N and 1.0N for female and male subjects, respectively. Also a tendency was observed for a logarithmic dependence between the loads exerted by perioral muscles on teeth and the acoustic pressure level due to the voice; in fact, the correlation coefficients R were, for some of the examined patients, >0.9, even if values of 0.4 also were observed.
Stress concentrations arising from a slot in a plate under biaxial stress
Authors: Rees D.W.A. 
Published: October 2008

AbstractThe stress distributions around a straight blunt slot under biaxial stress are found by adapting the classical solution to the stress concentration around an elliptical hole in an infinite plate under uniaxial stress. Firstly, the slot was converted into an equivalent thin ellipse of large major:minor axis ratio with its major equal to the length of the slot. The principle of superposition was then employed to find the stress state on an axis of symmetry at near and far locations from the notch tip. Stress states were found for any ratio of remotely applied stresses in directions perpendicular and parallel to the notch axis. The solutions were verified experimentally for specific tensile stress ratios by bonding strain gauges to an aluminium plate under hydraulic pressure.
Determination of material constants in creep continuum damage constitutive equations
Authors: Hyde T.H. , Sun W. , Tang A. 
Published: October 2008

AbstractExperimental creep and creep rupture data are presented for copper at 150, 200 and 250°C and for 0.5Cr0.5Mo0.25V steel at 640°C. Creep continuum damage constitutive equations have been shown to be capable of accurately representing the creep behaviour of both materials. A six variable optimisation program, which was developed to efficiently obtain the material constants, is described.
Theoretical design of calibration beams for strain gauge factor measuring apparatus
Authors: Zubin Deng 
Published: October 2008

AbstractBy starting with theoretical analysis and combining with the needs of practical applications, this article carries out a preliminary theoretical investigation of optimum design of the cross sectional shape and dimensions of calibration beams for strain gauge factor measuring apparatus. A new formula is derived in this paper that shows the quantitative relationship among strains on the beam surfaces, the strain non‐uniformity within a certain range of the beam and beam thickness, which provides a theoretical basis for the accuracy improvement of the measuring apparatus and for correct application of the calibration beams, and also for drawing up and improving items concerning with calibration beams in strain gauge standards internationally. It is proven through experiments that the neutral axis of the bent calibration beam of rectangular cross section under pure bending moments is actually not circular but parabolic.
Experimental analysis of surgically corrected knee joint
Authors: Bedzinski R. , Scigala K. 
Published: October 2008

AbstractHolographic interferometry, speckle photography and photoelasticity have been employed in the experimental investigations of the knee joint in four conditions ‐ anatomically normal joint, varus joint, joint after Coventry popliteal osteotomy and joint after correction made using a new variety of the Coventry procedure1. The studies included the investigations of the displacements of the bone in the sagittal plane, the displacements of points on the bone's surface in the frontal plane and the three dimensional state of stress. The obtained results show to what degree changes in the lower limb geometry affect the knee joint and in particular, its stability, functionality and the way in which it carries loads.
Vibratory weld conditioning — the effect of rigid body motion vibration during welding
Authors: Munsi A.S.M.Y. , Waddell A.J. , Walker C.A. 
Published: October 2008

AbstractPrevious studies suggested that the state of residual stress in a weld may be modified by vibration during and after the welding process. In this study, the effect of rigid body motion vibration on welding residual stresses was investigated. The specimens were welded while they were being vibrated in a rigid body motion mode. The specimens were vibrated using two different frequencies (50 Hz and 500 Hz). At the lower frequency vibration (50 Hz), small changes in the residual stresses were found, with no particular trend. At the high frequency vibration, no significant reductions in the residual stresses were observed in the longitudinal stresses or in the transverse direction. Some initial results are presented also regarding flexural vibration effects.
Distributed Measurement of Strain using Optical‐fibre Backscatter Polarimetry
Authors: Rogers A.J. 
Published: October 2008

Abstract: Fully‐distributed optical‐fibre sensing (FDOFS) systems are developing rapidly and are offering significant advantages for measurement functions in a variety of structural applications, especially in the oil industry, the power supply industry, the aerospace industries and civil engineering construction.Polarization techniques are well established in FDOFS, and in the analysis of polarization‐mode dispersion (PMD) for optical‐fibre telecommunications. However, a major problem has been that of determining, from one end of the fibre, the distribution of the full polarization properties of a monomode optical fibre, along its length, with some specific spatial resolution.This paper will present a new technique for providing this full information, and thus for measuring the distribution of any parameter, external to the fibre, which can modify its polarization behaviour. As a result, for example, it becomes possible to measure simultaneously the distributions of temperature and of a strain field comprising, in the latter case, the longitudinal and the two transverse components of direct strain, plus the transverse shear strain.The technique comprises an extension of polarization‐optical time domain reflectometry (POTDR) [16], and necessitates on‐line processing. Details of the physical principles, the algorithms and the polarimetry will be presented, together with results illustrating the measurement accuracies which can be achieved.
Local Finite Element and Experimental Limit Loads of Cracked Piping Elbows Under Opening Bending
Authors: Yahiaoui K. , Moreton D.N. , Moffat D.G. 
Published: October 2008

Abstract: Finite element (FE) and experimental data of cracked, 88.9 mm outside diameter, 5.49 mm thick, short radius, carbon steel piping elbows under displacement controlled, opening bending are reported. Short and long defects with depth‐to‐thickness ratios ranging from shallow to through‐wall, axially or circumferentially centred about the bend crown centreline or intrados respectively, are considered.The FE predicted general deformation mechanisms and overall strain distributions compare well with the experimental observations. Also, the strains agree well with the experimental values away from the defects. However, in the immediate vicinity of the defect, the FE strain data give much more detail about the initiation and spread of plasticity as the loading is increased towards plastic collapse of the component, but specific integration point strain data reveals that the variations are large and that steep strain gradients are evident even within individual elements. This explains the poor comparisons with experimental data in these regions. Using the above type of data, in conjunction with the twice‐elastic slope (TES) method for the determination of plastic loads for the cases investigated, it has been shown that values lower than those obtained from similar global measurements (load‐displacement plots) are consistently obtained.
Gas Turbine Propulsion Plant Control
Authors: Whalley R. , Ebrahimi M. 
Published: October 2008

ABSTRACTA model of a gas turbine variable pitch propeller propulsion system for a warship is considered. The system inputs, for control purposes, are demanded fuel flow and propeller pitch angle. The principal output which is to be regulated is the propulsion shaft speed while shaft torque changes are to be suitably confined. An optimum, multivariable, minimum control effort regulation strategy is proposed enabling improved transient and constrained output interaction to be achieved. Simple passive feedback elements are employed. System regulation at full and half power is investigated.
Watch Turnover Support for Future Surface Combatants
Authors: Springs John , Weaver Melissa 
Published: October 2008

ABSTRACTDuring watch turnover in the Combat Information Center, warfighters rely upon verbal communications, standardized procedures, and personal memory to build the situation awareness needed to perform their jobs. The design and implementation of the systems they use require operators to integrate information through procedures. A user interface prototype for an automated watch turnover support system has been developed at the Integrated Command Environment (ICE) Lab at the Naval Surface Warfare Center in Dahlgren, Virginia. This prototype demonstrates how information from multiple shipboard systems could be integrated to a single source of information, enabling a more efficient and effective watch turnover process. An iterative development process allowed the documentation of watchstander information requirements, a categorization of information, and definition of user interface requirements.
Statistical Methods for Planning Diesel Engine Overhauls in the U. S. Coast Guard
Authors: Milkie C. M. , Perakis A. N. 
Published: October 2008

ABSTRACTThe United States Coast Guard has recently investigated new strategies to maintain cutter propulsion diesel engines. Reliability centered maintenance with statistical methods may allow the time between costly scheduled overhauls to be increased. One indicator of engine aging is the number of failures experienced with increasing operating hours. The purpose of this paper is to investigate the failure‐time relationship of the ALCO 251 marine diesel propulsion engine operated on Reliance class cutters. This analysis used exponential, Weibull, and three‐part composite Weibull failure density functions to model engine casualty data dating back to 1978. The data does not indicate the source of the engine failure, but every failure had a significant operational impact. Results indicate an increasing failure rate as the engine ages to the 24,000 hour overhaul time. The evidence indicates a constant failure useful life region, but the increasing failure rate from the Weibull models suggests that the periodic over‐hauls do not prevent wearout failures. As a result, the Coast Guard should consider refining diesel engine overhaul policy in order to prevent increasing age‐related failures.
Engineering the Total Ship: A System Perspective on Warships
Authors: Holden Richard 
Published: October 2008

AbstractThis paper describes warships as manmade systems. A discussion of systems in terms of their characteristics and behavior is given and used as a foundation for a perspective of a warship as an integrated whole and an element of the naval force. The symposium series titled “Engineering the Total Ship” is used as a source of technical material to describe warships, naval operations, and the Navy organization. A system perspective is provided that defines warships as an integrated whole made up of interacting parts. The relationship of the Navy organization to the characteristics of warships is discussed.