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Artykuły w czasopismach na temat "DUCTILE DESIGN"
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Radončić, Nedim, Wulf Schubert i Bernd Moritz. "Ductile support design". Geomechanik und Tunnelbau 2, nr 5 (październik 2009): 561–77. http://dx.doi.org/10.1002/geot.200900054.
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Castro, Julia de, i Thomas Keller. "Design of robust and ductile FRP structures incorporating ductile adhesive joints". Composites Part B: Engineering 41, nr 2 (marzec 2010): 148–56. http://dx.doi.org/10.1016/j.compositesb.2009.10.003.
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Lyamina, Elena, i Sergei Alexandrov. "Incorporation of a Fracture Criterion in Ideal Flow Design". Key Engineering Materials 713 (wrzesień 2016): 143–46. http://dx.doi.org/10.4028/www.scientific.net/kem.713.143.
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The theory of sheet and bulk ideal plastic flows is used for the preliminary design of metal forming processes. The present paper develops an approach to incorporate the Cockroft and Latham ductile fracture criterion in this design method for stationary bulk flows. In particular, it is demonstrated that the initiation of ductile fracture can be predicted without having the ideal flow solution for stress and strain in the plastic zone (it is only necessary to know that the solution exists). Using the approach proposed the initiation of ductile fracture in axisymmetric drawing is predicted.
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Li, Yunjie, Guo Yuan, Linlin Li, Jian Kang, Fengkai Yan, Pengju Du, Dierk Raabe i Guodong Wang. "Ductile 2-GPa steels with hierarchical substructure". Science 379, nr 6628 (13.01.2023): 168–73. http://dx.doi.org/10.1126/science.add7857.
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Mechanically strong and ductile load–carrying materials are needed in all sectors, from transportation to lightweight design to safe infrastructure. Yet, a grand challenge is to unify both features in one material. We show that a plain medium-manganese steel can be processed to have a tensile strength >2.2 gigapascals at a uniform elongation >20%. This requires a combination of multiple transversal forging, cryogenic treatment, and tempering steps. A hierarchical microstructure that consists of laminated and twofold topologically aligned martensite with finely dispersed retained austenite simultaneously activates multiple micromechanisms to strengthen and ductilize the material. The dislocation slip in the well-organized martensite and the gradual deformation-stimulated phase transformation synergistically produce the high ductility. Our nanostructure design strategy produces 2 gigapascal–strength and yet ductile steels that have attractive composition and the potential to be produced at large industrial scales.
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Megget, Leslie M. "From brittle to ductile". Bulletin of the New Zealand Society for Earthquake Engineering 39, nr 3 (30.09.2006): 158–69. http://dx.doi.org/10.5459/bnzsee.39.3.158-169.
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This paper traces the development of seismic structural design in New Zealand since the 1931 Hawke’s Bay Earthquake, with emphasis on reinforced concrete buildings. From the mainly rigid and brittle unreinforced masonry structures which behaved so poorly in the 1931 earthquake through the development of flexible ductile seismic design and base (seismic) isolation of the 60’s to 80’s to today where the structural engineer is expected to design and construct a building which will not only remain standing with little damage but will be operational a short time after the major earthquake. In some ways the structural design aims and objectives have turned full circle in the intervening 75 years. We have gone from brittle rigid structures through a period where flexibility was paramount to now where flexibility is limited and greater lateral stiffnesses are required, but with ductile elements in the structure. This paper traces the efforts of New Zealand’s pre-eminent structural engineers and scientists to make seismic design techniques world leading. In most facets they have been successful (in my view) but as I will say more than once, only time will tell!
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Park, Robert. "Ductile Design Approach for Reinforced Concrete Frames". Earthquake Spectra 2, nr 3 (maj 1986): 565–619. http://dx.doi.org/10.1193/1.1585398.
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In the design of multistorey moment-resisting reinforced concrete frames to resist severe earthquakes the emphasis should be on good structural concepts and detailing of reinforcement. Poor structural concepts can lead to major damage or collapse due to column sidesway mechanisms or excessive twisting as a result of soft storeys or lack of structural symmetry or uniformity. Poor detailing of reinforcement can lead to brittle connections, inadequate anchorage of reinforcement, or insufficient transverse reinforcement to prevent shear failure, premature buckling of compressed bars or crushing of compressed concrete. In the seismic provisions of the New Zealand concrete design code special considerations are given to the ratio of column flexural strength to beam flexural strength necessary to reduce the likelihood of plastic hinges forming simultaneously in the top and bottom of columns, the ratio of shear strength to flexural strength necessary to avoid shear failures in beams and columns at large inelastic deformations, the detailing of beams and columns for adequate flexural strength and ductility, and the detailing of beams, columns and beam-column joints for adequate shear resistance and bar anchorage. Differences exist between current United States and New Zealand code provisions for detailing beams and columns for ductility and for the design of beam-column joints.
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Tomasi, Roberto, Maria Adelaide Parisi i Maurizio Piazza. "Ductile Design of Glued-Laminated Timber Beams". Practice Periodical on Structural Design and Construction 14, nr 3 (sierpień 2009): 113–22. http://dx.doi.org/10.1061/(asce)1084-0680(2009)14:3(113).
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Paulay, Thomas. "Are Existing Seismic Torsion Provisions Achieving the Design Aims?" Earthquake Spectra 13, nr 2 (maj 1997): 259–79. http://dx.doi.org/10.1193/1.1585945.
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A simple approach to the consideration of torsional effects on the ductile seismic response of buildings is suggested. Instead of increasing torsional strength, the control of twist, which may amplify local inelastic translational deformations, is emphasised. This may be achieved when assuring in the design that some residual stiffness in ductile systems is available. To this end a classification in terms of torsional restraint is suggested. It is postulated that traditional codified techniques, based on the evaluation of torsional effects on elastic systems, are largely irrelevant to ductile structural response. The primary consideration of inelastic deformation demands rather than strength is advocated. The presentation addresses foremost concepts of torsional behaviour and their relevance to routine seismic design, rather than advancement in analytical techniques.
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Rhee, Inkyu, Nakhyun Chun i Jae-Min Kim. "Failure Analysis of a Concrete Anchor under Severe Seismic Action". Applied Sciences 11, nr 21 (26.10.2021): 10019. http://dx.doi.org/10.3390/app112110019.
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We explored the usage of a response modification factor and overstrength factor for analyzing brittle or ductile failure of anchor system. Parametric studies on the tension and shear behaviors of anchor systems were compared in terms of elastic and ductile design using tuned Gyeongju earthquake data (ca. 0.3 g). We evaluated the yields of concrete anchors in terms of ductile failure and reviewed the various anchors, anchor attachments, and facilities and equipment that ensure anchor safety and functionality. The pseudo-static pushover test and elastic/inelastic dynamic tests revealed that a ductile design reduces the seismic demand relatively efficiently. As the DS-0050 design standards are based on strength design, no displacement limit for non-structural facilities/equipment is imposed. Despite the advantages of ductile design, large displacements of equipment or facilities during seismic action can cause permanent deformation and fall-out of major compartments; also, rapid functional recovery may be difficult. Thus, displacement limits for non-structural equipment or facilities should be included in the design code.
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Paulay, T., i W. J. Goodsir. "The capacity design of reinforced concrete hybrid structures for multistorey buildings". Bulletin of the New Zealand Society for Earthquake Engineering 19, nr 1 (31.03.1986): 1–17. http://dx.doi.org/10.5459/bnzsee.19.1.1-17.
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To complement existing capacity design procedures used in New Zealand for reinforced concrete buildings in which earthquake resistance is provided by ductile frames or ductile structural walls, an analogous methodology is presented for the design of ductile hybrid structures. Modelling and types of structures in which the mode of wall contribution is different are briefly described. A step by step description of a capacity design procedure for a structural system in which fixed base ductile frames and walls, both of identical height, interact, is presented. The rationale for each step is outlined and, where necessary, evidence is offered for the selection of particular design parameters and their magnitudes. A number of issues which require further study are briefly outlined. These relate to irregularity in layout, torsional effects, diaphragm flexibility, shortcomings in the predictions for dynamic shear demands in walls, and to limitations of the proposed design procedure. It is believed that the methodology is logical, relatively simple and that it should ensure, when combined with appropriate detailing, excellent seismic structural response.
Rozprawy doktorskie na temat "DUCTILE DESIGN"
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Castillo, Rolando. "Seismic design of asymmetric ductile systems". Thesis, University of Canterbury. Department of Civil Engineering, 2004. http://hdl.handle.net/10092/5055.
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The research promotes a better understanding of the response of torsionally unrestrained and
restrained ductile systems by examining the mechanism developed during the torsional response
of systems as they are affected by the dynamic actions of the translational and rotational mass.
A simple but effective design strategy for the seismic design of torsionally asymmetric systems
is suggested based on the estimate of the system displacement ductility capacity and the
distribution of the estimated system strength to its elements. The strength eccentricity is
considered the main parameter to influence the ductile response of asymmetric systems.
The possible success of the design strategy to limit displacement demands of the elements to less
than their displacement ductility capacity, for zero and increasing strength eccentricities, was
examined against the effects of key parameters expected to influence response. These
parameters are: strength eccentricity and the associated increase of system strength, mass
eccentricity, ratio of radii of gyration of strength and mass, reduced system displacement
ductility capacity, transverse elements and their degree of torsional restraint, the ratio of element
nominal yield displacement, i.e., α=Δye2/Δye1. and associated stiffness eccentricity, uncoupled
translational period, consideration of different earthquake records and their direction of
application.
Elements are modelled with a realistic relationship between element strength, stiffness and
nominal yield displacement. The stiffness is strength dependant and the nominal yield
displacement is a geometric and material property independent of strength. The centre of
strength and stiffness are, therefore, not independent parameters.
This research focuses on analytical studies of torsionally unrestrained and restrained single-mass
asymmetric systems. Single, two and multi-element systems were examined. An experimental
programme was also undertaken on single-mass models to verify some of the analytical findings.
The findings suggest that the suggested design strategy is successful in limiting the displacement
demands on elements to less than their displacement capacity for zero and increasing strength
eccentricities. No differentiation is required between systems having or not having mass
eccentricity. The proposed design strategy is slightly different for torsionally unrestrained and
restrained systems. It promises to be straightforward, rational and in terms of design efforts most
user friendly.
2
Boivin, Yannick. "New capacity design methods for seismic design of ductile RC shear walls". Thèse, Université de Sherbrooke, 2012. http://savoirs.usherbrooke.ca/handle/11143/1962.
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In order to produce economical seismic designs, the modern building codes allow reducing seismic design forces if the seismic force resisting system (SFRS) of a building is designed to develop an identified mechanism of inelastic lateral response. The capacity design aims to ensure that the inelastic mechanism develops as intended and no undesirable failure modes occur. Since the 1984 edition, this design approach is implemented in the Canadian Standards Association (CSA) standard A23.3 for seismic design of ductile reinforced concrete (RC) shear walls with the objectives of providing sufficient flexural and shear strength to confine the mechanism to the identified plastic hinges and ensure a flexure-governed inelastic lateral response of the walls. For a single regular wall, the implemented capacity design requirements assume a lateral deformation of the wall in its fundamental lateral mode of vibration, and hence aim to constrain the inelastic mechanism at the expected base plastic hinge. This design is referred to as single plastic-hinge (SPH) design. Despite these requirements, CSA standard A23.3 did not prescribe, prior to the 2004 edition, any methods for determining capacity design envelopes for flexural and shear strength design of ductile RC shear walls over their height. Only its Commentary recommended such methods. However, various studies suggested, mainly for cantilever walls, that the application of these methods could result in multistorey wall designs experiencing the formation of unintended plastic hinges at the upper storeys and a high potential of undesirable shear failure, principally at the wall base, jeopardizing the intended ductile flexural response of the wall. These design issues result from an underestimation of dynamic amplification due to lateral modes of vibration higher than the fundamental lateral mode. The 2004 CSA standard A23.3 now prescribes capacity design methods intending in part to address these design issues. Although these methods have not been assessed yet, their formulation appears deficient in accounting for the higher mode amplification effects. In this regard, this research project proposes for CSA standard A23.3 new capacity design methods, considering these effects, for a SPH design of regular ductile RC cantilever walls used as SFRS for multistorey buildings. In order to achieve this objective, first a seismic performance assessment of a realistic ductile shear wall system designed according to the 2004 CSA standard A23.3 is carried out to assess the prescribed capacity design methods. Secondly, an extensive parametric study based on sophisticated inelastic dynamic simulations is conducted to investigate the influence of various parameters on the higher mode amplification effects, and hence on the seismic force demand, in regular ductile RC cantilever walls designed with the 2004 CSA standard A23.3. Thirdly, a review of various capacity design methods proposed in the current literature and recommended by design codes for a SPH design is performed. From the outcomes of this review and the parametric study, new capacity design methods are proposed and a discussion on the limitations of these methods and on their applicability to various wall systems is presented.
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Weston, Neil R. "Development of energy dissipating ductile cladding for passive control of building seismic response". Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/13052.
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Tanaka, Hitoshi. "Effect of lateral confining reinforcement on the ductile behaviour of reinforced concrete columns". Thesis, University of Canterbury. Civil Engineering, 1990. http://hdl.handle.net/10092/1241.
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This thesis is concerned with the effects of lateral confining reinforcement on the ductile behaviour of reinforced concrete columns. The contents of the chapters are summarized as follows. In Chapter one, the general problems in seismic design are discussed and earthquake design methods based on the ductile design approach are described. Japanese, New Zealand and United States design codes are compared. Finally, the scope of this research project is outlined. In Chapter two, after reviewing previous research on confined concrete, the factors which affect the effectiveness of lateral confinement are discussed. Especially the effects of the yield strength of transverse reinforcement, the compressive strength of plain concrete and the strain gradient in the column section due to bending are discussed based on tests which were conducted by the author et al at Kyoto University and Akashi Technological College, Japan. In the axial compression tests on spirally reinforced concrete cylinders (150 mm in diameter by 300 mm in height), the yield strength of transverse reinforcement and the compressive strength of plain concrete were varied from 161 MPa to 1352 MPa and from 17 MPa to 60 MPa, respectively, as experimental parameters. It is found that, when high strength spirals are used as confining reinforcement, the strength and ductility of the confined core concrete are remarkably enhanced but need to be estimated assuming several failure modes which could occur. These are based on the observations that concrete cylinders with high strength spirals suddenly failed at a concrete compressive strain of 2 to 3.5 % due to explosive crushing of the core concrete between the spiral bars or due to bearing failure of the core concrete immediately beneath the spiral bars, while the concrete cylinders with ordinary strength spirals failed in a gentle manner normally observed. In addition, eccentric loading tests were conducted on concrete columns with 200 mm square section confined by square spirals. It is found that the effectiveness of confining reinforcement is reduced by the presence of the strain gradient along the transverse section of column. In Chapter three, the effectiveness of transverse reinforcement with various types of anchorage details which simplify the fabrication of reinforcing cages are investigated. Eight reinforced concrete columns, with either 400 mm or 550 mm square cross sections, were tested subjected to axial compression loading and cyclic lateral loading which simulated a severe earthquake. The transverse reinforcement consisted of arrangements of square perimeter hoops with 135° end hooks, cross ties with 90° and 135° or 180° end hooks, and 'U' and 'J' shaped cross ties and perimeter hoops with tension splices. Conclusions are reached with regard to the effectiveness of the tested anchorage details in the plastic hinge regions of columns designed for earthquake resistance. In Chapter four, the effectiveness of interlocking spirals as transverse reinforcement is studied. Firstly, the general aspects and the related problems of interlocking spirals to provide adequate ductility in the potential plastic hinge region of columns are discussed, referring to the provisions in the New Zealand code,the CALTRANS (California Transportation Authority) code and other related codes. Secondly, based on those discussions, a design method to securely interlock the spirals is proposed. Thirdly, the effectiveness of interlocking spirals is assessed based on column tests conducted as part of this study. Three columns with interlocking spirals and, for comparison, one rectangular column with rectangular hoopsandcross ties, were tested under cyclic horizontal loading which simulated a severe earthquake. The sections of those columns were 400 mm by 600 mm. In Chapter five, analytical models to investigate the buckling behaviour of longitudinal reinforcement restrained by cross ties with 90° and 135° end hooks and by peripheral hoops are proposed. The analyzed results using the proposed models compare well with the experimental observations described in Chapter three. Using those proposed models, a method to check the effectiveness of cross ties with 90° and 135° end hooks is proposed for practical design purposes. In Chapter six, a theory for the prediction of the ultimate longitudinal compressive concrete strain at the stage of first hoop fracture referred to as the "Energy Balance Theory", which has been developed by Mander, Priestley and Park at University of Canterbury, is introduced. After discussing the problems in the "Energy Balance Theory", a modified theory for the prediction of the ultimate longitudinal compressive concrete strain at the stage of first hoop fracture is proposed. The predictions from the modified theory are found to compare well with previous experimental results.
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Giles, Tyler Eric. "Ductile Design and Predicted Inelastic Response of Steel Moment Frame Buildings for Extreme Wind Loads". BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/9161.
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Inelastic design methods have been used in seismic design for several years and are well accepted in engineering practice. In contrast, an inelastic wind design method is yet to be developed, in part due to the inherent differences between seismic forces and wind forces. Current wind design practice follows a linear method to find a design windspeed for the location where the structure will be built. Once the design windspeed has been determined, the lateral force resisting system is designed such that it will behave elastically. This study was conducted with the hypothesis that by providing ductility at the material level, member level, and system level it may be possible to use a reduced design force for wind (i.e., a design force reduction that is proportional to a wind response modification factor). A three-story office building that uses steel moment frames as the primary lateral force resisting system was examined to test the hypothesis. Various levels of ductility were included based on ductility requirements for material strength, section stability and system stability originally developed for seismic design. Moment frames were designed for a range of design windspeeds and for three levels of ductility. For each design windspeed, a non-ductile (representing the moment frame as it would be designed by current standards), moderately-ductile and highly-ductile moment frame were developed. A finite element model of the building was made to capture inelastic material behavior and large displacements. The finite element model was subjected to wind loads based on wind tunnel tests data, and the static pushover, vibration, and dynamic responses of the building were evaluated. The performance of each moderately-ductile and highly-ductile moment frame was compared to the performance of each non-ductile frame of a higher design windspeed. The results show that for moderately-ductile moment frames, a wind response modification factor equal to 2 provided a collapse capacity that met or exceeded the collapse capacity of the comparative nonductile moment frame. For highly-ductile moment frames, a wind response modification factor equal to 3 met or exceeded the collapse capacity of the comparative non-ductile moment frame. In many instances, the collapse capacity of the moderately-ductile moment frame was similar to the collapse capacity of the highly-ductile moment frame. Thus, the results indicate that the use of a response modification factor for wind may be viable.
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Yan, Charlotte. "Vaildation of nonlinear FE-simulation for design improvement". Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-114592.
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The aim of the project is to develop a model, which is going to be used for mass reduction of a standard profile of aluminium seat rails in Aircraft structure. Using nonlinear analysis including plasticity and material failure laws the effect of changes in geometry vs. ultimate load is analysed (ABAQUS 6.11). First, the non-linear model used is validated with experimental testing: Boundary conditions and material properties are adjusted based on load displacement curves, strain gauges information and failure patterns. Less than 1% deviation is achieved between simulation and testing. An inclusion of material imperfection led to a 5% improvement of the results. Using the validated algorithm, a mass reduction is performed via geometry variationZiel der Studie ist es ein adäquates Simulationsmodell zu entwickeln, welches zur Gewichtsreduzierung einer Standardprofil Aluminium Sitzschiene im Flugzeug verwendet werden kann. In einer nichtlinearen Analyse unter Berücksichtigung der Plastizität des Materials und von Materialfehlern wird die Auswirkung der Geometrieänderungen auf die maximale Traglast analysiert (ABAQUS 6.11). Zunächst wird das nicht-lineare Modell mit experimentell ermittelten Daten überprüft: Randbedingungen und Materialeigenschaften werden basierend auf Lastverschiebungskurven, Informationen von Dehnungsmessstreifen und Versagensmustern angepasst. Dabei wurden weniger als 1% Abweichung zwischen Simulation und Test erzielt. Die Berücksichtigung von Materialfehlern führte zu einer 5%-igen Verbesserung der Ergebnisse. Mit dem validierten Modell wird abschließend eine Gewichtsreduzierung mittels Geometrievariation durchgeführt
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Karageyik, Can. "Displacement-based Seismic Rehabilitation Of Non-ductile Rc Frames With Added Shear Walls". Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611626/index.pdf.
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Non-ductile reinforced concrete frame buildings constitute an important part of the vulnerable buildings in seismic regions of the world. Collapse of non-ductile multi story concrete buildings during strong earthquakes in the past resulted in severe casualties and economic losses. Their rehabilitation through retrofitting is a critical issue in reducing seismic risks worldwide.
A displacement-based retrofitting approach is presented in this study for seismic retrofitting of medium height non-ductile concrete frames. A minimum amount of shear walls are added for maintaining the deformation levels below the critical level dictated by the existing columns in the critical story, which is usually at the ground story. Detailing of shear walls are based on conforming to the reduced deformation demands of the retrofitted frame/wall system. Member-end rotations are employed as the response parameters for performance evaluation. Initial results obtained from the proposed displacement based approach have revealed that jacketing of columns and confining the end regions of added shear walls are usually unnecessary compared to the conventional force-based approach, where excessive force and deformation capacities are provided regardless of the actual deformation demands.
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Shrestha, Kishor. "Use of flexible and ductile roof diaphragms in the seismic design of single-storey steel buildings". Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107802.
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This thesis documents an investigation of the use of the roof diaphragm flexibility in the seismic design and analysis procedure of single-storey steel buildings designed otherwise in accordance with the provisions of the 2010 NBCC and the 2009 CSA S16. The design approach considers the members of the vertical bracing system as the ductile fuse elements in the seismic force resisting system (SFRS), whereas the diaphragm remains elastic. An alternative design approach was also examined in which the steel deck roof diaphragm acts as a ductile fuse element in the SFRS; at present this procedure is not permitted by the NBCC or CSA S16. The investigation was reliant on a complementary three phase test program in which nineteen large-scale roof diaphragm specimens were dynamically excited with a sequence of increasing amplitude loading protocols. The first part of the study comprised the development of a deep horizontal plane truss numerical model using the OpenSees software platform to reproduce the dynamic characteristics as well as the elastic and inelastic response of the nineteen test specimens. The predicted fundamental period of vibration, the elastic response and the inelastic hysteretic response were compared with the test results and the models were calibrated accordingly. In the second part of the study, the detailed design and non-linear time history dynamic analyses of representative medium size and large size single-storey steel buildings were carried out. The intent was to evaluate the overall behaviour of four structural systems whose design was tailored to either rely on the flexibility of the diaphragm or to allow the roof decking / connections to deform inelastically. OpenSees building models were developed by integrating a non-linear brace model with the non-linear diaphragm model. Dynamic analyses were performed on the designed buildings using the corresponding OpenSees building model and responses were evaluated under a suite of design level earthquake signals. The study illustrated that the analytically predicted fundamental period of vibration which includes the influence of the roof deck diaphragm could be used in the design of such single-storey steel buildings. This finding leads to the recommendation to revise the expression given in 2010 NBCC for the fundamental period of vibration as well as for the period limitation. Further, compared to the different structural systems, the buildings designed with EBF structural system were found most promising in terms of the relative capacity force on the steel deck diaphragm and the building response. The study also found that the diaphragms in the EBF and CBF structural systems could be designed for the force corresponding to the seismic base shear with RdRo = 2, if it controls the design. Moreover, significant shear strength degradation and concentration of inelastic demand were observed in the diaphragm at the edge of the buildings when the steel decks were parallel to the loading direction and the diaphragm was designed as a ductile fuse element. This illustrates that the value of 2.0 that was assumed for the seismic force reduction parameter Rd may not be appropriate in the design of such buildings. Similar strength degradation and concentration of inelastic demand in the diaphragm were observed in the buildings with a Type CC structural system, which shows that the diaphragm may need to be designed corresponding to the elastic seismic force.La présente thèse porte sur une recherche sur l'utilisation de la flexibilité du diaphragme de toit dans la conception et l'analyse parasismiques des bâtiments d'un seul étage en acier conçus selon les dispositions parasismiques des normes de construction CNBC 2010 et CSA S16-09. L'approche de conception consiste à considérer les diagonales de contreventement faisant partie du système de résistance aux forces sismiques (SRFS) comme les éléments ductiles, alors que le comportement du diaphragme de toit demeure dans le domaine élastique. Une approche différente a aussi été examinée selon laquelle le diaphragme de toit en acier agit comme un élément ductile dans le SFRS, approche qui n'est pas autorisée dans les codes CNBC et CSA S16 présentement en vigueur. L'étude est tributaire d'un programme d'essais complémentaires en trois phases durant lequel dix-neuf spécimens de diaphragme de toit à grande échelle ont été soumis à des essais dynamiques selon un protocole de chargement à amplitude variable. La première partie de l'étude a porté sur l'élaboration avec le logiciel OpenSees d'un modèle numérique de diaphragme de toit composé d'un système de treillis afin de reproduire les caractéristiques dynamiques de même que les comportements élastique et inélastique des dix neuf spécimens. Les prédictions de la période fondamentale de vibration, du comportement élastique et de la réponse sous sollicitation inélastique cyclique ont été comparées aux résultats des essais au laboratoire, et les modèles ont été ajustés en conséquence. Dans le seconde partie du programme d'essais, la conception de différents bâtiments à un étage de taille moyenne et de taille grande, ainsi que l'analyse non-linéaire de ceux-ci, a été complétée. L'objectif était d'évaluer le comportement global de quatre systèmes structuraux dont la conception avait été adaptée pour prendre en compte la flexibilité du diaphragme de toit ou permettre les déformations inélastiques des connecteurs du tablier métallique. Des modèles des bâtiments ont été développés avec le logiciel OpenSees, en intégrant un modèle non linéaire des diagonales et le modèle non linéaire du diaphragme. Des analyses dynamiques des bâtiments ainsi conçus ont été réalisées avec le logiciel OpenSees et leur comportement a été évalué sous un ensemble de mouvements de sol sismique d'amplitude correspondant au niveau sismique de conception. L'étude à démontré que la période qui inclus l'influence du diaphragme peut être utilisée dans la conception d'un bâtiment à un étage en acier avec ce type de construction. Cette découverte mène à la recommandation de réviser l'expression du CNBC 2010 pour la période fondamentale du bâtiment ainsi que la limite empirique sur celle-ci. Les bâtiments construits avec un système de contreventements de type excentrique sont les plus prometteurs au niveau de la capacité relative du diaphragme en acier et la comportement du bâtiment. L'étude a aussi démontré que les diaphragmes qui sont unis avec un système de contreventements concentriques ou excentriques peuvent êtres conçus pour la force qui correspond au cisaillement calculé avec RdRo = 2, si celui-ci contrôle la conception du diaphragme. Il faut aussi noter qu'une dégradation significative de la capacité en cisaillement et une concentration de la demande élastique à été observée aux côtés des bâtiments quand la tôle est installée parallèle à la direction de la charge et quand le diaphragme est conçu comme l'élément sacrifiant. Ceci illustre le fait que la valeur de 2.0 assumé pour la ductilité du système (Rd) n'est pas nécessairement appropriée pour la conception de ce genre de bâtiments. Cette même concentration de la demande aux côtes et dégradation du système a aussi été observée dans les bâtiments conçus avec un système latéral de type 'construction conventionnelle' ce qui veut dire que le diaphragme devrait sans doute être construit pour la force sismique élastique.
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Zerkane, Ali S. H. "Cyclic Loading Behavior of CFRP-Wrapped Non-Ductile Reinforced Concrete Beam-Column Joints". PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/3000.
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Use of fiber reinforced polymer (FRP) material has been a good solution for many problems in many fields. FRP is available in different types (carbon and glass) and shapes (sheets, rods, and laminates). Civil engineers have used this material to overcome the weakness of concrete members that may have been caused by substandard design or due to changes in the load distribution or to correct the weakness of concrete structures over time specially those subjected to hostile weather conditions. The attachment of FRP material to concrete surfaces to promote the function of the concrete members within the frame system is called Externally Bonded Fiber Reinforced Polymer Systems. Another common way to use the FRP is called Near Surface Mounted (NSM) whereby the material is inserted into the concrete members through grooves within the concrete cover. Concrete beam-column joints designed and constructed before 1970s were characterized by weak column-strong beam. Lack of transverse reinforcement within the joint reign, hence lack of ductility in the joints, and weak concrete could be one of the main reasons that many concrete buildings failed during earthquakes around the world. A technique was used in the present work to compensate for the lack of transverse reinforcement in the beam-column joint by using the carbon fiber reinforced polymer (CFRP) sheets as an Externally Bonded Fiber Reinforced Polymer System in order to retrofit the joint region, and to transfer the failure to the concrete beams. Six specimens in one third scale were designed, constructed, and tested. The proposed retrofitting technique proved to be very effective in improving the behavior of non-ductile beam-column joints, and to change the final mode of failure. The comparison between beam-column joints before and after retrofitting is presented in this study as exhibited by load versus deflection, load versus CFRP strain, energy dissipation, and ductility.
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Lessmann, Moritz. "Non-ductile design of demo divertor armour : towards the probabilistic reliability assessment of brittle tungsten components in their irradiated state". Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/nonductile-design-of-demo-divertor-armour-towards-the-probabilistic-reliability-assessment-of-brittle-tungsten-components-in-their-irradiated-state(2be9bcee-5d9f-41cc-82fb-4f7b662b0a6a).html.
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In-vessel tungsten components of a future demonstration fusion reactor are likely to be operated in the material's non-ductile regime. Assessment of the components' reliability is not possible with current ductile design codes or through experimental qualification. There is therefore an urgent need for non-ductile assessment procedures. One such approach currently considered is Weibull's weakest link theory, which is based on linear-elastic fracture mechanics and has its origins in ceramics. A full assessment of its validity has been performed, and the challenge of obtaining irradiated material data addressed. Bend tests at the macroscopic scale confirm previous findings that the scatter in strength of pure tungsten follows a two-parameter Weibull distribution, provided the material fractures within its elastic regime. However, tests conducted over a range of specimen sizes reveal the technique's shortcomings in accurately predicting the material's size effect in fracture, questioning its applicability to pure tungsten and also other brittle metallic materials. Fracture strength tests conducted at the micrometre scale through cantilever bending have addressed the challenge of obtaining irradiated material data. An ultra-fine grained self-passivating tungsten alloy, considered as an alternative contender to tungsten for in-vessel components, is shown to fracture within its linear-elastic regime at the microscopic scale. A reliable and repeatable measurement of its strength of approximately 5.9 GPa is obtained. The scatter in measurements is shown to be greater than random errors, and to be described well by a two-parameter Weibull distribution. Cantilever tests conducted over a range of specimen sizes reveal a strong size effect (4.3 - 9.0 GPa), which is accurately predicted by Weibull's weakest link theory. Ion implantations, conducted in the tungsten alloy to mimic neutron induced elastic collision damage, result in a statistically confirmed drop (6 %) in cantilever measured fracture strength at low doses (0.7 dpa), and an increase (9-16 %) at higher doses (7 dpa).The cantilever test technique is therefore suitable for the measurement of ion and neutron irradiation effects on the material's fracture strength. Provided a full validation of Weibull's weakest link theory strength extrapolation from the micro- to macroscopic scale is realised on a future heterogeneity free material batch, irradiated material data obtained from cantilever tests could be used to assess the reliability of in-vessel components fabricated from a self-passivating tungsten alloy, and fill the current gap in non-ductile design assessment procedures.
Książki na temat "DUCTILE DESIGN"
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Chia-Ming, Uang, i Whittaker Andrew Stuart, red. Ductile design of steel structures. New York: McGraw-Hill, 1998.
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Chia-Ming, Uang, i Whittaker Andrew (Andrew Stuart), red. Ductile design of steel structures. Wyd. 2. New York: McGraw-Hill, 2011.
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Ductile Iron Pipe Research Association (U.S.). Thrust restraint design for ductile iron pipe. Wyd. 4. Birmingham, Ala. (245 Riverchase Pkwy. East, Suite O, Birmingham 35244): Ductile Iron Pipe Research Association, 1997.
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Ductile Iron Pipe Research Association (U.S.), red. Thrust restraint design for ductile iron pipe. Wyd. 2. Birmingham, Ala: Ductile Iron Pipe Research Association, 1986.
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Works, American Water. C150-14 Thickness Design of Ductile-Iron Pipe. American Water Works Association, 2014.
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Gaston, Maury. AWWA C150-21 Thickness Design of Ductile-Iron Pipe. American Water Works Association, 2022.
Znajdź pełny tekst źródłaCzęści książek na temat "DUCTILE DESIGN"
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Leckie, Frederick A., i Dominic J. Dal Bello. "Ductile Materials and Design". W Strength and Stiffness of Engineering Systems, 1–57. Boston, MA: Springer US, 2008. http://dx.doi.org/10.1007/978-0-387-49474-6_12.
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Spaniel, M. "Numerical Simulation of Ductile Fracture". W The Latest Methods of Construction Design, 277–82. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-22762-7_41.
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Zhou, Ming, Ying Chun Liang i Shao Nan Huang. "Ultraprecision Ductile-Regime Cutting of Optical Glass". W Optics Design and Precision Manufacturing Technologies, 69–73. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-458-8.69.
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Curtin, W. A., Rasool Ahmad, Binglun Yin i Zhaoxuan Wu. "Design of Ductile Rare-Earth-Free Magnesium Alloys". W Magnesium Technology 2020, 19–24. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-36647-6_5.
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Alberti, N., i F. Micari. "Forming Processes Design Oriented to Prevent Ductile Fractures". W Advanced Manufacturing Systems and Technology, 47–61. Vienna: Springer Vienna, 1996. http://dx.doi.org/10.1007/978-3-7091-2678-3_5.
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Campione, G., P. Colajanni i N. Scibilia. "Behaviour of concrete walls coupled by ductile links with semi-rigid connections". W European Seismic Design Practice, 203–10. London: Routledge, 2022. http://dx.doi.org/10.1201/9780203756492-32.
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Mahmoud, Adel K. "Surface Hardening of Ductile Cast - Iron Using Pulsed Laser Beams". W Design, Fabrication and Economy of Metal Structures, 639–44. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-36691-8_95.
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Bhuwal, A. S., Y. Pang, T. Liu, I. Ashcroft i W. Sun. "Data-driven design of high ductile metamaterials under uniaxial tension". W Current Perspectives and New Directions in Mechanics, Modelling and Design of Structural Systems, 333–38. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003348443-54.
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Bhuwal, A. S., Y. Pang, T. Liu, I. Ashcroft i W. Sun. "Data-driven design of high ductile metamaterials under uniaxial tension". W Current Perspectives and New Directions in Mechanics, Modelling and Design of Structural Systems, 115–16. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003348450-54.
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Salem, Yasser S., Guseppe Leminto i Trung Tran. "Analytical Fragility Curves for Non-Ductile Reinforced Concrete Buildings Retrofitted with Viscoelastic Dampers". W Design and Construction of Smart Cities, 31–38. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-64217-4_4.
Pełny tekst źródłaStreszczenia konferencji na temat "DUCTILE DESIGN"
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Ficca, Jeremy. "Ductile Empiricism". W 2017 ACSA Annual Conference. ACSA Press, 2017. http://dx.doi.org/10.35483/acsa.amp.105.24.
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Evolving modes of representation and communication continue to redefine the flow of information between designer, fabricator and manufacturer, while nimble means of fabrication recalibrate customization. As various types and scales of design practice reveal, opportunities for strategic collaboration between designer and fabricator abound. The work illustrated is the result of the first phase of a university-industry partnership with a global manufacturer of metal façadesystems. Our industry partner sought to capitalize upon the alternate perspective the students and by extension, the academy afforded to reconsider the standard metal façade panel that has served as the core of their business. We sought to structure a collaboration that strategically leveraged the material expertise of our industry partner while encouraging structured experimentation by the students, that was initially unconstrained from the myriad of technical and economic considerations associated with building cladding systems.
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Konig, Wilfried. "Ductile grinding of ultraprecise aspherical optical lenses". W Lens and Optical Systems Design. SPIE, 1993. http://dx.doi.org/10.1117/12.142836.
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Eschenauer, H. A., i T. Vietor. "Aspects in the Shape Optimization Using Brittle and Ductile Materials". W ASME 1992 Design Technical Conferences. American Society of Mechanical Engineers, 1992. http://dx.doi.org/10.1115/detc1992-0100.
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Abstract The use of advanced materials will increasingly gain importance in future developments of constructions in mechanical, electrical and civil engineering. For this reason, the material behaviour in particular has to be considered when finding optimal layouts for components. Here, the different failure mechanisms of the applied materials must be taken into consideration. This paper presents a comparison between conventional, ductile materials and brittle ceramics as an example of an advanced material. In order to find a failure criterion which is characteristic of the material, stochastic models of the defects determining the failure of ceramic materials have been included. A strong variation in the calculated optimal design shows that an accurate consideration of the material behaviour and its mathematical description is important for the results to be found. The use of conventional stress criteria does not suffice for ceramic materials.
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Jordan, Sarah, Mark DeBruin, Christopher Brown i Hudson Gasvoda. "Design Considerations for Lightweighting with Ductile Iron Castings". W WCX SAE World Congress Experience. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2020. http://dx.doi.org/10.4271/2020-01-0656.
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Ma, H., R. J. Bowers, D. O. Northwood, X. Sun i P. J. Bauerle. "Residual stress and retained austenite in induction hardened ductile iron camshafts". W TRIBOLOGY AND DESIGN 2012. Southampton, UK: WIT Press, 2012. http://dx.doi.org/10.2495/td120101.
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Schmidt, Frank, i Thomas N. Dobras. "Driven Ductile Iron Pipe Piles: Design, Installation, and Performance". W International Foundation Congress and Equipment Expo 2009. Reston, VA: American Society of Civil Engineers, 2009. http://dx.doi.org/10.1061/41021(335)37.
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Zohourkari, Iman, i Mehdi Zohoor. "Mathematical Modeling of Abrasive Waterjet Turning of Ductile Materials". W ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2010. http://dx.doi.org/10.1115/esda2010-25288.
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In this paper, an erosion-based model for abrasive waterjet (AWJ) turning process is presented. In the AWJ turning process a particular volume of material is removed by impacting of abrasive particles to the surface of the rotating cylindrical workpiece. This volume is estimated according to the modified Hashish erosion model; thus radius reduction at each revolution is calculated. The distinctively proposed model considers the continuous change in local impact angle due to change in workpiece diameter, axial traverse speed of the jet, the abrasive particle roundness and density. The accuracy of the proposed model is approved by experimental tests under various traverse speeds. The final diameters estimated by the new model are in good accordance with the experiments.
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"How to Increase Ductile Behavior of Reinforced Concrete Structures". W SP-340: Dennis Mertz Symposium on Design and Evaluation of Concrete Bridges. American Concrete Institute, 2020. http://dx.doi.org/10.14359/51725814.
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Tartaglia, John M., Paige E. Ritter, Richard B. Gundlach i Lyle Jenkins. "Monotonic and Cyclic Property Design Data for Ductile Iron Castings". W SAE 2000 World Congress. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2000. http://dx.doi.org/10.4271/2000-01-0758.
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Xu, Yun-Yun, Zhen-Rong Lin i Tao Zhang. "Design features and significance of the ductile reinforced concrete frame structure". W The 2015 International Conference on Design, Manufacturing and Mechatronics (ICDMM2015). WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814730518_0023.
Pełny tekst źródłaRaporty organizacyjne na temat "DUCTILE DESIGN"
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Wolodko. L52036 High Pressure Design for New Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), luty 2005. http://dx.doi.org/10.55274/r0011118.
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The objective of this project was to review the state-of-the-art with respect to high pressure pipelines and to evaluate the technical feasibility of high pressure designs for new construction of onshore pipelines. The study includes a review of issues pertaining to the implementation of high pressure pipeline designs, as well as detailed analysis in two identified areas of importance: 1) the sizing of potential impact zones for high pressure, rich gas service, and 2) the assessment of various ductile fracture arrest models.
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Biagio, Massimo Di. PR-182-124505-R04 Developing Tools to Assure Safety Against Crack Propagation. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), marzec 2018. http://dx.doi.org/10.55274/r0011472.
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Recent industry experience is showing that modern lower grade steels (X60 to X70) are not having the same fracture behavior as older steels of the same grade. As a major consequence, past material qualification test methods may be no longer valid for these new steels and may not provide safe design guidance, both for the evaluation of the brittle to ductile transition temperature and for the prediction of ductile fracture arrest requirements. MAT-8-1 Project Phase 2 was specifically focused on brittle-to-ductile transition temperature assessment and may ultimately lead to reliable testing methods to evaluate the behavior of modern steels, to allow the industry to design safe gas pipelines. Specific small and full-scale experimental activities have been carried out, with the aim to verify the correspondence between the brittle-to-ductile transition temperatures determined using different small-scale sample geometries and comparing the results with four full-scale West Jefferson tests.
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Perez, Felipe de Jesus. Lateral Load Behavior and Design of Unbonded Post-tensioned Precast Concrete Walls with Ductile Vertical Joint Connectors. Precast/Prestressed Concrete Institute, 1998. http://dx.doi.org/10.15554/pci.rr.seis-018.
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Kanninen, M. F. L51718 Development and Validation of a Ductile Fracture Analysis Model. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), maj 1994. http://dx.doi.org/10.55274/r0010321.
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In close cooperation with the Centro Sviluppo Materiali (CSM) and SNAM of Italy, with several years of support from the PRCI NG-18 committee, the Southwest Research Institute (SwRI) has developed and validated a "first principles" predictive model for ductile fracture in a gas transmission pipeline. In particular, the coordinated SwRI and CSM projects for the PRC -supplemented by work contributed by SNAM - has established a theoretically valid methodology and an accompanying line pipe material characterization procedure for gas industry use. This progress provides a theoretically sound framework for designing and operating gas transmission pipelines to be without risk of a large-scale ductile fracture event. However, there remained two important aspects of this technology that needed to be addressed before practical use of the methodology could be made by gas transmission companies. First, because the preceding projects concentrated on pipes with natural gas, to cover the full range of gas transmission pipeline service, the approach needed to be extended to include the effects of gases rich in hydrocarbons. Second, as the number of full-scale pipe fracture experiments that were included in the developmental phase of the research were limited, other data for validation of the model needed to be identified and employed. These two aspects of the ductile fracture methodology development process were conducted concurrently, and have now been completed. The progress that has been provided in detail in this report. The work is culminated by a relation through which the methodology can be applied by pipeline engineers to assess the possibility of a ductile fracture propagation. This report describes the development of a predictive model for ductile fracture in a gas transmission pipeline, thus providing a theoretically sound framework for designing and operating gas pipelines to be without risk of a large-scale ductile fracture event. The model represents an improvement on a number of empirical relations used in designing natural gas pipelines in that this model has been generalized to consider a wide-range of hydrocarbon contents and validated through both additional full-scale instrumented tests carried out by Centro Sviluppo Materiali of Italy and computer simulations conducted at Southwest Research Institute. Application of the model in pipeline design is based on determination of the maximum driving force for fracture, as described in the report, and contrasting this value with measured material resistance that provides a basis for assessing the likelihood of ductile fracture occurring. For existing pipelines the procedure can be used to obtain the maximum operating line pressure that will not put the pipeline at risk of ductile fracture.
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Malik. L51877 Crack Arrest Toughness to Avoid Dynamic Ductile Fracture in Gas Transmission Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), marzec 2001. http://dx.doi.org/10.55274/r0010192.
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Design against long ductile fracture propagation in gas pipelines involves an analysis of the balance between driving force, derived from the gas pressure, and the fracture resistance of the material. Initially, the shelf energy in the Charpy test was successfully used as a measure of fracture propagation resistance. As material strength, pipe diameter and operating pressures increased and required greater fracture propagation resistance, the limitations of the Charpy energy approach became increasingly apparent. This limitation for modern steels is due to the fact that the Charpy test involves significant energy absorption contributions from processes not related to fracture propagation. If an energy-balance approach is to be maintained, and if material resistance is to be measured in a fairly simple laboratory notch bend test (e.g. Charpy or drop-weight tear), the problem reduces to the isolation of the propagation energy absorption per unit of crack advance. To resolve crack propagation energy, a novel modification was evaluated for both Charpy and DWTT specimens by employing a back-slot including a snug fitting shim to replace the removed material. In most cases, this modification was effective in curtailing the load-displacement trace when the propagating crack interacted with the slot on the backside of the specimen. It is also noted that this approach did not affect the initial portion of the load-displacement history and thus allowed crack propagation energies to be resolved.
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Wilkowski, Gery. PR-276-184501-R01 Toughness Specification to Avoid Brittle Fracture in New Linepipe Steels. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), marzec 2020. http://dx.doi.org/10.55274/r0011658.
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Historically, Charpy test results have been used for assessing linepipe steels for fitness-for-service or new pipeline design, and the linepipe steels should be chosen such that the brittle-to-ductile transition temperature of the steel is below the minimum design service temperature. The transition temperature is typically much different for crack initiation versus crack propagation. This study focused on the transition temperature for fracture initiation which is important for liquid as well as high-energy lines. However, in recent studies, different behavior between vintage and newer steels has been noticed for the fracture initiation transition temperature relative to Charpy data. Even the fracture surface appearance in the Charpy test is much different for vintage steels than for newer steels. To investigate the above issues, the objectives of the current project were set to: a) determine if the fracture initiation transition temperature for new linepipe steels is similar to that in older steels, and how to predict it better if Charpy data are insufficient; and b) understand if the Charpy energy requirement for API 5L PSL-2 linepipe is always adequate to ensure ductile fracture initiation at the Charpy test temperature. In this project, the transition temperature behaviors of three linepipe steels from the Charpy test data, results from drop-weight tests to determine the nil-ductility temperature or DWT-NDT, and findings from more sophisticated fracture tests such as single-edge-notched tension [SEN(T)] that is representative of surface-cracked pipe behavior, and compact tension [C(T)] specimen tests that are representative of through-wall-cracked pipe behavior were determined. The report summarizes the key findings of the project for newer steels and attempts to contrast fracture initiation behavior in vintage versus newer linepipe steels.
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Weeks, Timothy "Dash". DTPH56-13-X-000013 Modern High-Toughness Steels for Fracture Propagation and Arrest Assessment-Phase II. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), wrzesień 2018. http://dx.doi.org/10.55274/r0012037.
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NIST work developed processes to identify the stress/strain/crack velocity conditions for unstable high-rate ductile crack propagation found in a full-scale pipeline burst test and duplicate those conditions in a medium-scale test. With modeling to validate conditions and assumptions used in reducing the scale of the tests. A medium-scale test to elucidate material property data necessary to qualify high-strength high-toughness steels based on the correlation to large-scale tests. Parametric determination of the material properties governing fracture propagation or arrest-ability was developed. This will assist researchers to determine a relevant and effective small-scale test (or tests) that provides enough information for material selection, design, reliability, as well as integrity and risk assessment. Pipe evaluated includes API5L X70 and X80 pipe. The strain was measured by a three-dimensional digital image correlation system. This project takes a phased approach with complementary research in successive phases beginning with a road map to systematically fill gaps in knowledge and understanding of the problem of unstable high-rate ductile running failures in pipelines. This report is structured to highlight the problem statement with respect to the current state of the art understanding, define knowledge gaps and present the plan, and progress toward meeting the objective. The following sections specifically cover the effort to develop and inform a constitutive material model necessary for the structural model of the medium-scale test. The material testing required to inform the constitutive material model is presented. Conclusions of this phase of the project are also presented in addition to the proposed work in Phase III of the project.
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Biagio, Di. L52037 Ductile Fracture Propagation Resistance for Advanced Pipeline Designs. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), styczeń 2008. http://dx.doi.org/10.55274/r0011001.
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The development of a method able to evaluate the ductile fracture behavior on pipelines has been documented. Therefore, methods for the determination of material fracture resistance and crack driving force have been accurately investigated. In particular, the techniques to determine the critical fracture characterizing parameter CTOA (crack tip opening angle) have been reviewed in-depth (back-slotted drop weight tear tests [DWTT], two specimen CTOA tests, etc.), and in view of a future pipe-mill application. For a more reliable CTOA estimate the needed following parameters have been investigated: 1) rotation factor in a DWTT and 2) the material flow stress to be used in dynamic tests. On the other hand, as far as the crack driving force is concerned, a finite element code developed by CSM (PICPRO) has been successfully used to evaluate the correlation between the CTOA inferred by DWT tests and that measured on pipe. In addition PICPRO has been used to determine the driving force acting on pipe in a wide range of operating conditions, finally supplying an appropriate formula for its calculation. Once the driving force and the fracture resistance have been determined their comparison allows crack arrest assessment.
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RUTHERFORD, J. Design Analysis Report for 244-AR Interim Stabilization Exhaust Ventilation Ducting. Office of Scientific and Technical Information (OSTI), listopad 2002. http://dx.doi.org/10.2172/808406.
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Shen, Gianetto i Tyson. L52342 Development of Procedure for Low-Constraint Toughness Testing Using a Single-Specimen Technique. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), grudzień 2011. http://dx.doi.org/10.55274/r0010687.
Pełny tekst źródłaStreszczenie:
Pipelines from remote frontier regions are increasingly required to have adequate resistance to large deformations such as that caused by ground movement. In response to this, �strain-based design"� has been developed to enable assessment of imperfections at applied strains beyond yield. In addition, it is proposed to take advantage of the increased apparent toughness of pipe under low constraint, such as girth weld imperfections under axial tension, compared with the high-constraint toughness measured in conventional tests such as ASTM E1290 [1]. Application of low-constraint testing has been dvantageously applied in assessment of toughness for offshore pipeline projects. Also in the pipeline industry, demands on new pipeline projects include low design temperatures as well as high strain capacity. At the same time, increased strength is specified, which increases the level of required toughness. These factors make it increasingly important to assure weldment toughness, in particular to ensure that the failure mode remains ductile. It is well known that brittle cleavage is especially sensitive to constraint, and the availability of a toughness test that would reproduce field conditions would enable more rational development and acceptance of candidate welds and, in particular, enable more appropriate testing of weld heat-affected zones. This work was performed for specific application to surface circumferential cracks in pipe under strain-based design, for which the best constraint matching has been found to occur for clamped single-edge tension (SE(T)) specimens with H/W=10. For this geometry, a test procedure similar to that of ASTM E1820-06 for single-edge bend (SE(B)) and compact tension (C(T)) specimens was developed for J-resistance tests using a single-specimen technique. All the equations used in the procedure, including those for evaluation of J-integrals from the area under load/plastic crack mouth opening displacement (CMOD) curves, and evaluation of crack length from unloading compliance including rotation correction, were developed using finite element analysis (FEA) with a range of crack depths, focusing on a/W= 0.2 to 0.5 which is of most practical interest. The present procedure is compared with that of E1820 for SE(B) testing regarding evaluation of J-integral with crack growth correction, crack length evaluation, and correction of compliance for rotation.