bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue testing of interlocking Stainless Steel
Authors: Chen Z. , Reuben R. L. , Owen D. G. 
Published: October 2008

AbstractAn interlock tube, usually made of stainless steel, is one of the key structural components for both bonded and unbonded flexible pipes of composite construction. The fatigue performance of this component is an important factor in determining the long term integrity of the entire pipe.This paper presents an experimental technique developed for the establishment of the basic fatigue characteristics of such interlock tubes. Details of the fatigue testing method, the specimen design, preparation and calibration procedures will be described in conjunction with tests carried out on 254 mm interlock tube samples.One of the most important results from this work is that, by careful design and machining of the specimen, the mode of failure seen in full scale pipe samples can be reproduced on small specimens in a laboratory using a fatigue machine. The significance of this is that it is possible to obviate the necessity for expensive full scale composite pipe testing, provided that an accurate description of the loading conditions imposed on components of the composite is available.
Stress‐strain analysis of a biaxial tension cruciform specimen for tests under creep conditions
Authors: Waniewski M. , Wolf U. , Brietbach G. 
Published: October 2008

AbstractA flat cruciform specimen for experimental tests either in the elastic or the inelastic range is investigated. Mutually perpendicular biaxial tension forces applied to the edges of specimen arms produce in its thinnest part in plane biaxial stresses. The stated goal of the study is to assess the extent to which a uniform stress state is achieved within the thin, central gauge area of the specimen. It is shown, by applying the FE code ABAQUS, that in the transition between the thin and the thick part of the specimen stress concentrations occur and that the redistribution of stress due to creep will not produce a more uniform stress state. An isotropic, elastic ‐ viscoplastic constitutive description has been employed within the context of small deformations. The calculations were carried out for three different ratios of biaxial loading. The results are displayed for both the initial (i.e. immediately following load application) stress distribution and the steady state stress distribution within the specimen. Experimental validation is discussed.
The failure of an armour faced conveyor connector
Authors: Rudd W.J. , Osselton J.E. 
Published: October 2008

AbstractThe combined use of modern metallurgical techniques for fracture examination, laboratory test data and fracture mechanics calculations allows metallurgical failures to be examined in a quantitative manner. Complex load histories and environments can result in more than one sub‐critical cracking mechanism occurring in a component. Quantitative understanding of the rate determining cracking process is a necessary prerequisite to rectifying the problem.The following case study describes a connector from an armour faced conveyor which failed in service. The failure investigation involved fractography, stress analysis, material property evaluation and fracture mechanics calculations. Fractographic evidence indicated a stress corrosion failure mechanism. Calculations of critical crack sizes showed that stress corrosion cracking alone could not account for the fracture. It was concluded that the failure was due to a sequence of three cracking processes which preceded unstable ductile fracture. Firstly, frictional heating caused rubbing or quench cracks typically 0.5–1 mm deep. Secondly, corrosion fatigue cracks grew several millimetres allowing the third fracture process, stress corrosion cracking, (SCC) to initiate and grow. In the situation described here, this process was much faster than corrosion fatigue.The influence of defect size due to rubbing cracks and the influence of KISCC have been compared with the corrosion fatigue life of the component. An increase in KISCC and hence critical defect size for SCC has been shown to increase the corrosion fatigue life of the component by a large factor. A change in design would also alleviate the problem of SCC by reducing the static stress, which is the driving force for SCC.
Holographic investigation into the mechanical behaviour of engineering ceramics
Authors: Chirico G. Di , Rossi R. 
Published: October 2008

AbstractThe complex loading conditions to which a structural component is customarily subjected require a knowledge of the material responses to combined stresses, while almost all the data available for ceramic materials are obtained from uniaxial tests. It is necessary, therefore, to study the behaviour of engineering ceramics using specimens of proper shapes subjected to biaxial stresses and testing methods that enable high sensitivity monitoring and real time analysis of the surface strains. In this respect, an optical technique such as conjugate wave holographic interferometry gives satisfactory results. Characterisation tests are carried out on diametrically loaded discs in order to evaluate Young's modulus and Poisson's ratio of some classes of ceramic materials.
A temperature calibration of a temperature/strain transducer based on two strain gauges
Authors: Cappa P. , McConnell K. , Zachary L. 
Published: October 2008

AbstractThe operation of a temperature/strain transducer, called “duplex gauge”, based on two electrical resistance strain gauges, that are temperature compensated for use on materials with different coefficients of linear expansion, was briefly recalled. Three steel specimens were equipped with “duplex gauges” and were subjected to temperature variations and no external loads were applied. The chosen experimental setup (i) to measure the outputs of the gauge temperature compensated for steel and titanium silicate and (ii) to impose known temperature, assured good accuracy and precision in evaluation of the temperature calibration curve. The obtained results showed that the strain differences could be considered, at least for the experimental arrangement examined, a linear function of temperature over the range of 20 to over 140°C. The prepared calibration chart, that allows the correction of temperature induced apparent strain, will be used in future research when generic temperature and strain fields are applied to specimens.
Measurements for the Bloodhound project: a historical account
Authors: Collins S.J. 
Published: October 2008

AbstractThe paper covers the design of the transducer based measuring equipment required to support the development of a guided missile system. The exciting challenges presented by such a project are highlighted including the extent to which ingenuity was stretched. The plethora of devices which were spawned by these endeavours had many future applications in the commercial world and is a pointer to the type of secondary benefits that can ensue.
Measurement of in plane residual displacement due to interference fitting by TV‐holographic interferometry
Authors: Chan Yiu Wing 
Published: October 2008

AbstractExperimental measurements of the in plane residual displacement field surrounding the cold expanded holes in aluminium plates of 100mm × 100mm × 10mm were made using the technique of TV‐holographic interferometry. A special cold expansion fixture was designed to produce precise radial interferences of 0.015mm and 0.025mm at the hole walls. The experimentally determined displacement fields were compared with those obtained by finite element predictions. The experimental results showed good agreement with those obtained by finite element analysis. These results demonstrate that the TV‐holographic interferometry technique can be used as an effective technique for general deformation investigations.
Experimental errors in the application of photoelastic coatings on human femurs with uncemented hip stems
Authors: Cristofolini Luca , Cappello Angelo , Toni Aldo 
Published: October 2008

AbstractThe investigation of the stress distribution in the proximal femur is of primary relevance when testing hip prostheses. Most of the in‐vitro research to date, has been conducted with strain gauges. However, the photoelastic coatings provide a field vision of the state of strain and of the most stressed points. The purpose of this work was to validate the application of photoelastic coatings to intact and implanted human femurs. Coatings of various thickness were bonded to two regions: the surface of the diaphysis, and the resection surface of the neck. A theoretical study was conducted on a geometrical model of the diaphysis to quantify some of the experimental errors. The reinforcing effect was found to be far the most important source of error for the coating of the diaphysis. Other possible sources of error such as Poisson's coefficient mismatch, incorrect light incidence angle and uneven coating thickness were also examined. Due to the uneven distribution of such errors, any correction seems impossible. The results must therefore be considered only qualitatively, as a complement to the strain gauging. The coating of the resection surface of the neck of the femur suffers much less from the reinforcing effect, but the coating is more sensitive to Poisson's coefficient mismatch. In this second application, quantitative results can be satisfactorily obtained.
Strains measured on plane and curved surfaces by means of the shearographic method ‐ Part 1
Authors: Steinchen W. , Schuth M. , Yang L. X. 
Published: October 2008

AbstractThe shearographic interferometry is employed as a nondestructive full field, optical testing method without contact. Fringes of constant strain (so called isotase, tasis (Greek)=strain) can be observed in real time on the surface of the investigated machine parts and are represented by the shearograms. Using shearography two states of deformation are recorded by doubly exposing a Holotest film in an ordinary camera or stored by an image processing system. In the telelens of the camera a shearing element inside or outside the focus is integrated. Rigid body motions of the specimen are not recorded. Local deformation irregularities caused by a defect under or on the surface of the specimen create strain concentrations; the homogeneous surrounding is poorly superimposed by an interference pattern, e.g., in the case of the internal pressure differential for testing tubes1. The shearogram shows dark and bright fringes which are the functions of the displacement derivative. The holographic interferometry measures the out of plane deformations directly. A term of the out of plane strain can be determined by the shearographic method2 as well as the in plane strain fringes under certain conditions which are described in the following. For this purpose the fringe patterns generated by the basic types of loading are presented and compared with the photoelastic patterns showing obvious analogies. The magnitude of the shearographic strain components is nearly the same when measuring by means of strain gauges or determining theoretically as is shown for one case.
Applications of experimental techniques to solid mechanics and materials science research in telecommunications and electronics
Authors: Dudderar T.D. 
Published: October 2008

AbstractIn the effort to support the rational development of reliable, manufacturable leading edge communications technologies, a broad variety of experimental mechanics and materials techniques have been developed and/or applied at the AT& Bell Laboratories in Murray Hill, NJ. Much of the emphasis in this paper is on the application of optical methods to the conduct of experimental mechanics and materials research relevant to the telecommunications and electronics industries. It will also describe the role such research plays in supporting the development of a new process or product.This paper is based on a presentation at the BSSM/SEM International Conference on “Advances in engineering measurements” held at The University of Edinburgh, 30 August to 01 September 1994.
Progress in experimental stress analysis for Airbus aircraft design
Authors: O'Brien E.W. 
Published: October 2008

AbstractAdvanced experimental stress analysis techniques have been increasingly used on large aircraft structures to provide stress data for both design and numerical analyses validation. In the past these techniques tended to be limited to the structural test phase which is subsequent to the design and manufacture stage. Experimental stress techniques have had to become more sophisticated and utilised much earlier in the programme in order to meet the ever increasing demands for competitive, aircraft design, performance and reliability. Currently the techniques have applications from the earliest design stage through to final in‐service support engineering. Photoelastic stress analysis was one of the earliest and most powerful experimental design tools in use at Filton, however, the range of techniques is continually being extended to meet the technological demands of new designs. This has involved keeping abreast of a wide array of sciences to identify and develop new physical procedures for stress related experimental analysis. Progress is reviewed in this paper as well as the vision for the future within the context of Airbus aircraft design. The economic and technical pressures to move towards more automation and image processing are discussed including the requirement to provide data that is more user friendly to conventionally trained design and stress engineers.
Strain gauge proof hydraulic testing of commercial pressure vessels
Authors: Taylor D.A.W. 
Published: October 2008

AbstractSome aspects of the philosophy of shakedown are presented relevant to the requirement of the British pressure vessel code British Standard BS 55(X): 1994 for proof hydraulic pressure tests on vessels containing features not covered in the design rules within BS 55(X). The difficulties in achieving the objective of the test are discussed. Examples are provided from the experiences gathered from such proof hydraulic tests on over 50 commercial pressure vessels.
Three fringe photoelasticity ‐ use of colour image processing hardware to automate ordering of isochromatics
Authors: Ramesh K. , Deshmukh Sanjeev S. 
Published: October 2008

AbstractThe early application of digital image processing (DIP) technique to automate photoelastic analysis is based on black and white (B & W) image processing systems. The various methodologies reported can be traced to rely upon one or several features of a B &W DIP system. With the advancements in computer technology, nowadays colour image processing systems are available at affordable prices. A systematic study has been carried out on how to use the red green blue (RGB) value recorded using a colour image processing system for determining fringe orders up to 3 in a fringe field. The study has revealed that instead of directly using RGB values corresponding to a dark field image, if the difference of RGB values between bright anddarkfield images is used, the number of noise points is less. Experiments have been carried out for several arbitrary lines in a circular disk under diametral compression and the results are found to be good.
Effect of plasticity on the residual stress measurement using the groove method
Authors: Petrucci G. , Zuccarello B. 
Published: October 2008

AbstractThe mechanical methods based on milling rectilinear or annular grooves on a component's surface and measurement of relaxed strains are some of the most used semi‐destructive methods for the determination of residual stresses. These are evaluated from the relaxed strains by means of equations based upon the linear elastic theory. In this paper the errors due to yielding localised at the bottom of the groove have been investigated. The analyses were carried out by means of the finite element technique varying the most important parameters involved. The experimental results show a good agreement with the numerical ones.
The good, the bad and the ugly: An engineer's view of product liability litigation in the United States
Authors: Fourney M.E. 
Published: October 2008

AbstractThis talk presents a cross section of case studies which exemplified the best and the worst of the system. The technical aspects of each case, along with the legal theories and the final resolution is discussed. The author will present his philosophical prospective of the process based on over 25 years experience.
On the correction of plasticity effect at the hole edge when using the centre hole method for measuring high welding residual stress
Authors: Yan Zhao Hai , Wu Shi Yao , Yi Pei , Pin Lei Yong , Jun Chen Yue 
Published: October 2008

AbstractSignificant error caused by plasticity at the hole edge may arise when measuring sufficiently high welding residual stress by means of the hole drilling method. According to elastoplastic theory, a critical parameter of plastic deformation round the centre hole is obtained. On the basis of this critical parameter, a simple method is proposed to correct the stresses for the plasticity effect. It is shown in the experiments with welded joints that the correction method may improve the accuracy of high residual stress measurement.
New techniques in the elastic analysis of arch bridges using image processing
Authors: Prentice D.J. , Ponniah D.A. 
Published: October 2008

AbstractThe importance of the masonry arch in Britain's infrastructure has never been more significant than at the present time with ever increasing axle loads under new EEC regulations The searches have been shown to be significantly affected by the overlying fill. The effect of this fill is being investigated by a number of methods employing a variety of experimental techniques. This paper presents one such new technique of examining the effects of the fill through monitoring zones of strain on an arch model subjected to load. The model arches were constructed in timber with a dry granular fill and approximately 90 tests were carried out to investigate the effect of load position, fill depth and pier stiffness. Image analysis of the tests permitted identification of the areas of strain within the fill and arch barrel and the location of the hinges at higher loads. Finite element (FE) analysis was used to model the arch in its elastic range and comparisons of the FE strain contour plots with the equivalent images illustrated the validity of using image processing for the determination of the strain characteristics. The practical applications of using such a technique are subsequently highlighted and commented on.
Non‐contact strain measurement using metal foil gauges with the application of the laser speckle method
Authors: Kato Akira , Nakai Hidetoshi , Tanabe Kiyoshi , Nagase Yasuo 
Published: October 2008

AbstractThis paper presents a new method to measure cyclic strain with no contact using metal foil gauges assisted by the laser speckle method. When aluminium foil is pasted on a specimen and the specimen is loaded cyclically, slip bands are produced on the foil surface. There is a fixed relation between density of the slip bands and the strain amplitude or loading cycles depending on the foil material. Thus the fatigue strain of the base metal can be estimated by observing the surface change of the metal foil by the slip bands at a constant number of loading cycles. The method presented in this paper is intended to make a non‐contacting strain measurement by the application of the laser speckle technique for the detection of the surface change. This method is based on observation of the changes in a laser speckle pattern depending on the surface roughness and surface property changes of the foil caused by fatigue. The laser speckle pattern can be analysed automatically and quantitatively using an image processing system.
A New Method to determine Triaxial Non‐Uniform Residual Stresses from Measurements using the Hole Drilling Method
Authors: Wern H. , Cavelius R. , Schläfer D. 
Published: October 2008

AbstractA new integral analysis technique in combination with finite element calibration data is introduced to resolve the triaxial residual stress profiles of measurements performed with the hole drilling or ring core method. The new technique uses an inverse formulation with symmetrised trigonometric basis functions or wavelets.
Residual deformation analysis of an aluminium plate irradiated by CO2 laser
Authors: Huimin Xie , Guotao Wang , Daqing Zou , Fulong Dai , Dietz Peter , Schmidt Axel 
Published: October 2008

AbstractIn this paper, a grid method was used to measure the residual deformation of a loaded aluminium plate irradiated by CO2 Laser. The residual strain fields near the illuminated area at different irradiation times were obtained. The experimental results were discussed in detail.
Towards a device independent digital image processing software for photoelastic analysis
Authors: Ramesh K. , Govindarajan R. 
Published: October 2008

AbstractThe application of digital image processing (DIP) techniques to photoelasticity has greatly simplified data reduction and analysis. The softwares reported so far are hardware dependent and hence not portable. A simple PC based device independent software for collection of photoelastic data from digitised fringe patterns is presented. The software is validated by evaluating the near crack tip stress field parameters for a crack subjected to mode I and mode II loadings.
Measurement techniques for buckling sensitive composite shells
Authors: Esong I. E. , Elghazouli A. Y. , Chryssanthopoulos M. K. 
Published: October 2008

AbstractThis paper describes a measurement system that was developed for an experimental study on buckling of glass reinforced composite cylinders. An automated non‐contact laser device operating inside the test specimen provided a three dimensional scanning system for measuring the deformation of the shell wall. The measurement system was used to obtain the initial geometric imperfections, as well as the deformation under varying control axial displacement. All loading and data acquisition operations were carried out using advanced computer controlled techniques. Due to the large number of measurements undertaken in each test, data collection was followed by processing and reduction techniques, thus delivering the data in a form suitable for finite element analysis and comparative studies. Typical results are presented in order to demonstrate the reliability, accuracy and versatility of the system.
The design of advanced aircraft structures to resist acoustic fatigue; work in progress
Authors: Cunninghamsp P.R. , Xiao Y. , White R.G. 
Published: October 2008

AbstractDetails of the current research activities in the Department of Aeronautics and Astronautics, on the response of advanced aircraft structures to acoustic loading, are presented. Both box type and sandwich structures, employing aluminium alloy, carbon fibre reinforced plastic, and GLARE composite materials, are being investigated. In order to develop design guidelines for these complex structures, it is necessary to combine theoretical predictions, using the finite element method, with experimental measurements of the structural response to random acoustic loading. Both types of structure will be tested in the Progressive Wave Tube facility at Southampton. In addition, it is hoped that a more comprehensive damping guide will be produced for the type of structure used in advanced aircraft design.