Academic literature on the topic 'Plastic slip'
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Journal articles on the topic "Plastic slip"
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Schmalzer, Andrew M., and A. Jeffrey Giacomin. "Die drool theory." Journal of Polymer Engineering 33, no. 1 (February 1, 2013): 1–18. http://dx.doi.org/10.1515/polyeng-2012-0044.
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Abstract When molten plastic is extruded from a die, it sometimes collects on the open face of the die. Known as die drool, this phenomenon costs plastics manufacturers by requiring die cleaning. This has been attributed to many causes, but none of these has led to an equation for the drool rate. In this work, we provide an exact analytical solution for the drool rate, and we base this solution on a postulate of a cohesive slip layer near the die walls. We thus attribute die drool to cohesive failure within the fluid at an internal surface where the fluid slips on itself. We adimensionalize the drool rate with the production rate, and call this the buildup ratio, BR. We provide an exact analytical solution for BR when the cohesive slip layer either slips at the die wall, or when it does not. We examine two important extrusion geometries: slit (which we then extend to pipe) and tube flow. We identify two new experiments: one to measure BR as a function of pressure drop, and another as a function of the die aspect ratio, and we then use our new theory to design droolometers.
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Kawano, Yoshiki, Tsuyoshi Mayama, Ryouji Kondou, and Tetsuya Ohashi. "Crystal Plasticity Analysis of Change in Active Slip Systems of α-Phase of Ti-6Al-4V Alloy under Cyclic Loading." Key Engineering Materials 725 (December 2016): 183–88. http://dx.doi.org/10.4028/www.scientific.net/kem.725.183.
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In this paper, we investigated changes in active slip systems of α-phase of Ti-6Al-4V alloy under a cyclic plastic loading using a crystal plasticity finite element method. In the analyses, a bicrystal model was employed, and the crystallographic orientations were set so as that prismatic <a> or basal slip system was the primary slip system in each grain. The results showed that there was a mechanism where the basal slip systems could reach the stage of activation under the cyclic plastic loading even though the condition was that the prismatic <a> slips initially operate. The reason for the activity changes was due to the changes in the incompatibility between the grains by the work hardening, and the effect of the incompatibility on activities of slip systems appeared even in the perpendicular arrangements of the grains to the loading direction.
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Zhu, Xiao Hua, Yu Wang, Fu Cheng Deng, Li Ping Tang, and Hua Tong. "Optimal Design of Slip Dog Based on the Elasticoplasticity Contact Analysis." Applied Mechanics and Materials 34-35 (October 2010): 1718–23. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.1718.
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Based on the elasticoplasticity contact analysis theory, a mechanical model for the whole process of the slip holding fast to the drilling pipe is established and a complete method is proposed to assess the performance of slip dog's structural parameters. For drilling pipe systems of different specifications, the coupling effect among tooth anterior corner, posterior corner, tooth height, tooth spacing of slip dog and the effect of the parameter variation on both the drilling pipe and itself after the slips hold fast to the drilling pipe are analyzed, and the slip dog's plastic damage law on the drilling pipe under different parameter combinations is obtained. Using this law to instruct field slip dog design, it is discovered that this slip dog significantly reduces the drilling pipe's plastic damage by both laboratory and field experiments, which has proved the universality and applicability of this method, effectively reduced the drilling operational risk and drilling costs. The technology has been put into use in Sichuan and Chongqing region and acquired good technical assessment.
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Yokogawa, Toshiya, Sachi Niki, Junko Maekawa, Masahiko Aoki, and Masaki Fujikane. "Dislocation Formation via an r-Plane Slip Initiated by Plastic Deformation during Nano-Indentation of a High Quality Bulk GaN Surface." MRS Advances 1, no. 58 (2016): 3847–52. http://dx.doi.org/10.1557/adv.2016.165.
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ABSTRACTBulk GaN substrates are of significant interest because they offer both high quality and low dislocation densities. Our group has previously reported the formation and movement of dislocations in high quality bulk GaN in response to nano-indentation. We have also proposed a mechanism involving an r-plane (-1012) slip initiated by plastic deformation during a pop-in event, a theory that was supported by molecular dynamics simulations. Herein, we present experimental evidence for this r-plane (-1012) slip mechanism in an indented GaN surface using nano-indentation with an indenter having a smaller radius (∼100 nm) and imparting a lower pop-in load (∼400 μN) compared to the values applied in our previous studies. In addition, this study included TEM observations immediately after the plastic deformation, such that cross-sectional TEM images of the indented surface of the c-plane bulk GaN were acquired just after the pop-in event. The pyramidal dislocation line of an r-plane slip was clearly observed and was inclined by 43° relative to the c-plane surface. Neither a basal c-plane slip nor a prism m-plane slip occurred as a result of dislocation multiplication as secondary or tertiary slip systems, even though these slips had been identified when employing a larger radius indenter and a higher pop-in load. From these experimental results, we were able to confirm that plastic deformation in bulk GaN is initiated via an r-plane slip.
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Zhu, Eryu, Teng Li, Haoran Liu, Chunqi Zhu, Lei Liu, Yuanyuan Tian, Yujie Li, and Wei Yang. "Bond-Slip Behavior between Plastic Bellow and Concrete." Advances in Materials Science and Engineering 2022 (June 14, 2022): 1–16. http://dx.doi.org/10.1155/2022/2450503.
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Despite the widespread use of plastic bellows in prestressed channels, their poor bonding with concrete and mortar results in “layering,” which limits their application in practical engineering. In this study, the bonding property between plastic bellows and concrete or grout material was investigated using a single-end compression test on plastic bellow concrete. The slip failure mode, ultimate load, and slip of plastic bellows were obtained. Furthermore, the analysis of the bond-slip properties of plastic bellows indicated that the bond strength decreased with increasing bond length. Moreover, the increase in the loading force was greater than the increase in the contact area. Based on the test data, a bond-slip constitutive relationship model was established, which accurately reflects the bond-slip process. The expressions of bond and slip were derived along with different bond positions of plastic bellow concrete specimens. Finally, a three-dimensional finite element model of a plastic bellow concrete specimen was established. The numerical simulation curve was compared with the experimental and fitting curves. The results indicated that the bond strength of the plastic bellow concrete specimen decreased with increasing bond length. The influence of bond strength on the contact area was comprehensively analyzed. This study effectively combines experimental research, theoretical analysis, and numerical simulation to analyze the bond performance between plastic bellows and concrete or grout material.
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Liu, Yun Xi, Wei Chen, Zhi Qiang Li, Liang Liang Liu, and Dong Liu. "In Situ Observation on the Deformation Behavior of Primary α-Ti in a Textured Ti-6Al-4V." Materials Science Forum 993 (May 2020): 365–73. http://dx.doi.org/10.4028/www.scientific.net/msf.993.365.
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The tensile deformation process and dislocation behavior of primary α-Ti of Ti-6Al-4V were studied by the in-situ tensile test combined with EBSD (electron backscatter diffraction). The initiation, evolution and distribution of dislocation slips at different strains were discussed. The results showed that the microtexture of the material had a significant influence on slip behavior. Typically, basal and prismatic <a> slips initiated first, but the dominant slip type was related to the local texture characteristics. Sometimes, the basal and prismatic <a> slips could still initiate when their Schmid factors were relatively low, while the pyramidal slips usually need a higher Schmid factor to initiate. With the increase of strain, the second slip system inside one grain was activated to accommodate the plastic deformation. When the deformation was localized in a specific microtextured region, basal <a> slips were dominant, but eventually the crack initiated from the <c+a> slip bands inside the grain.
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Ando, Shinji, Masayuki Tsushida, and Hiromoto Kitahara. "Plastic Deformation Behavior in Magnesium Alloy Single Crystals." Materials Science Forum 706-709 (January 2012): 1122–27. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.1122.
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Zn and Al are major alloying elements of Mg alloys. Main slip system of Mg is a basal slip and the CRSS increases with Zn or Al content. According to von-Mises criterion, five kinds of independent slip systems are required for uniform deformation, so it is necessary to activate non-basal slip systems to show good ductility. However, it has not become clear the effect of Zn or Al for non-basal slip systems yet. To investigate deformation behavior of magnesium crystal by non-basal slip, Mg-Zn and Mg-Al single crystals were stretched in the [110] direction and Mg-Zn single crystals were compressed in the [0001] direction. {112}<23> second order pyramidal slip was activated in Mg-0.1at%Zn and Mg-0.5at%Al. On the other hand, {101} twin was mainly activated in Mg-1.0at%Al alloy. Yield stress due to the pyramidal slip of magnesium decreased by 0.1at%Zn addition, however they increased with addition of aluminum..
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Ohashi, Tetsuya, Michihiro Sato, and Yuhki Shimazu. "Evaluation of Plastic Work Density, Strain Energy and Slip Multiplication Intensity at Some Typical Grain Boundary Triple Junctions." Materials Science Forum 654-656 (June 2010): 1283–86. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.1283.
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Plastic slip deformations of tricrystals with simplified geometries are numerically analyzed by a FEA-based crystal plasticity code. Accumulation of geometrically necessary (GN) dislocations, distributions of the total slip, plastic work density and GN dislocations on slip systems, as well as some indices for the intensity of slip multiplication are evaluated. Results show that coexistence of GN dislocations on different slip systems is prominent at triple junctions of grain boundaries.
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Gerdeen, J. C., W. W. Predebon, P. M. Schwab, and A. Shah. "Elastic-Plastic Analysis of Directionally Solidified Lamellar Eutectic Composites." Journal of Engineering Materials and Technology 109, no. 1 (January 1, 1987): 53–58. http://dx.doi.org/10.1115/1.3225933.
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Yielding in a crystal structure occurs with plastic slip on preferential planes. It is similar to yielding on maximum shear planes in an isotropic continuum, but in this case the slip is anisotropic. The anisotropic slip is described by 24 piecewise, continuous yield functions, also known as the generalized Schmid’s law for FCC crystals. The plastic strain increment for any one slip mechanism is assumed given by the potential flow law of plasticity. However, there are combined slip situations where two or more slip mechanisms are activated simultaneously. In this paper, the plastic strains for all the possible intersections in FCC crystals are derived, i.e., for intersections of two, four, and eight yield surfaces of compatible stress states. A strain hardening modulus H′ is included by defining an equivalent shear stress τ and an equivalent plastic shear strain γp for each slip system. The analysis is programmed for finite-element solution on the computer, by defining a strain “vector” {dε}, a stress “vector” {dσ}, and an elastic-plastic compliance [C] for each element, relating the strain and stress vectors. The analysis is applied to the elastic-plastic yielding of directionally solidified eutectic systems of Co-CoAl which solidify into a lamellar structure. A plane strain analysis is compared with experiments and good correlation is found for the stress concentration effect when the lamellae have termination points.
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Liu, Conghui, Rhys Thomas, João Quinta da Fonseca, and Michael Preuss. "Early slip activity and fatigue crack initiation of a near alpha titanium alloy." MATEC Web of Conferences 321 (2020): 11040. http://dx.doi.org/10.1051/matecconf/202032111040.
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For titanium alloys, crack initiation as a result of plastic strain accumulation has been shown to govern fatigue life under the high cycle fatigue regime. In this study, the early plastic slip activity and fatigue crack initiation was studied using a cyclic four point bending test at 10 Hz with a load ratio of 0.1, up to 90% of the proof stress. The plastic slip in the high stress area was monitored by interrupting the test and performing optical microscopy. Following fatigue crack initiation, scanning electron microscopy (SEM) combined with electron backscatter diffraction (EBSD) was used to identify the slip and crack initiation mode in a 600 x 600 μm2 area. Using slip trace analysis, it was shown that primary alpha grains offered dominant plastic deformation with basal slip activation. Cracking along basal planes was determined to be the dominant damage mode.
Dissertations / Theses on the topic "Plastic slip"
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Lloyd, Jeffrey Townsend. "Implications of limited slip in crystal plasticity." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34808.
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To better understand consequences of classical assumptions regarding deformation mechanisms at the mesoscale, experimental observations of mesoscale deformation are presented. In light of actual micrographics of deformed polycrystals, the Von Mises criterion which states that 5 independent plastic deformation sources are needed at each material point to satisfy compatibility is studied, and the consequences of violating this assumption are presented through comprehensive parametric studies. From these studies, it can be concluded that not only are 5 independent plastic deformation sources not needed or observed at each point, but if less than 5 sources are allowed to be active a new physical understanding of a mechanism for kinematic hardening emerges. Furthermore, for enhanced subgrain rotation and evolution the Von Mises criterion must be violated. The second focus of this work is looking at studies, experiments, and models of mesoscale deformation in order to better understand controlling deformation length scales, so that they can be fed into a combined top-down, bottom-up, non-uniform crystal plasticity model that captures the variability provided by the mesoscale during deformation. This can in turn be used to more accurately model the heterogeneity provided by the response of each grain. The length scale intuited from insight into mesoscale deformation mechanisms through observation of experiments and analytical models is the free slip line length of each slip system, which informs non-uniform material parameters in a crystal plasticity model that control the yielding, hardening, and subsequent softening of each individual slip system. The usefulness of this non-uniform multiscale crystal plasticity model is then explored with respect to its ability to reproduce experimentally measured responses at different strain levels for different size grains. Furthermore, a "Mantle-Core" type model which combines both the non-uniform material parameter model and the limited slip model is created, in which the majority of plastic deformation is accommodated near the grain boundary under multi-slip, and uniform plastic deformation occurs in the bulk dominated by double or triple slip. These models are compared for similar levels of hardening, and the pole figures that result from their deformation are compared to experimental pole figures. While there are other models that can capture the heterogeneity introduced by mesoscale deformation at the grain scale, this combined top-down, bottom-up multiscale crystal plasticity model is by far one of the most computationally efficient as the heterogeneity of the mesoscale is does not emerge by introducing higher order terms, but rather by incorporating the heterogeneity into a simple crystal plasticity formulation. Therefore, as computational power increases, this approach will be among the first that will be able to perform accurate polycrystal level modeling while retaining the heterogeneity introduced by non-local mesoscale deformation mechanisms at the sub-grain scale.
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Bayerschen, Eric [Verfasser]. "Single-crystal gradient plasticity with an accumulated plastic slip: Theory and applications / Eric Bayerschen." Karlsruhe : KIT Scientific Publishing, 2016. http://www.ksp.kit.edu.
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Chaloupka, Ondrej. "Modelling evolution of anisotropy in metals using crystal plasticity." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8435.
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Many metals used in modern engineering exhibit anisotropy. A common
assumption when modelling anisotropic metals is that the level of anisotropy is
fixed throughout the calculation. As it is well understood that processes such as
cold rolling, forging or shock loading change the level of anisotropy, it is clear
that this assumption is not accurate when dealing with large deformations.
The aim of this project was to develop a tool capable to predict large
deformations of a single crystal or crystalline aggregate of a metal of interest
and able to trace an evolution of anisotropy within the material.
The outcome of this project is a verified computational tool capable of predicting
large deformations in metals. This computational tool is built on the Crystal
Plasticity Finite Element Method (CPFEM). The CPFEM in this project is an
implementation of an existing constitutive model, based on the crystal plasticity
theory (the single crystal strength model), into the framework of the FEA
software DYNA3D® .
Accuracy of the new tool was validated for a large deformation of a single
crystal of an annealed OFHC copper at room temperature. The implementation
was also tested for a large deformation of a polycrystalline aggregate comprised
of 512 crystals of an annealed anisotropic OFHC copper in a uniaxial
compression and tension test. Here sufficient agreement with the experimental
data was not achieved and further investigation was proposed in order to find
out the cause of the discrepancy. Moreover, the behaviour of anisotropic metals
during a large deformation was modelled and it was demonstrated that this tool
is able to trace the evolution of anisotropy.
The main benefit of having this computational tool lies in virtual material testing.
This testing has the advantage over experiments in time and cost expenses.
This tool and its future improvements, which were proposed, will allow studying
evolution of anisotropy in FCC and BCC materials during dynamic finite
deformations, which can lead to current material models improvement.
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Crooks, Matthew Stuart. "Application of an elasto-plastic continuum model to problems in geophysics." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/application-of-an-elastoplastic-continuum-model-to-problems-in-geophysics(56bc2269-3eb2-47f9-8482-b62e8e053b76).html.
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A model for stress and strain accumulation in strike slip earthquake faults is presented in which a finite width cuboidal fault region is embedded between two cuboidal tectonic plates. Elasto-plastic continuum constitutive equations model the gouge in the fault and the tectonic plates are linear elastic solids obeying the generalised Hooke's law. The model predicts a velocity field which is comparable to surface deformations. The plastic behaviour of the fault material allows the velocities in the tectonic plate to increase to values which are independent of the distance from the fault. Both of the non-trivial stress and strain components accumulate most significantly in the vicinity of the fault. The release of these strains during a dynamic earthquake event would produce the most severe deformations at the fault which is consistent with observations and the notion of an epicenter. The accumulations in the model, however, are at depths larger than would be expected. Plastic strains build up most significantly at the base of the fault which is in yield for the longest length of time but additionally is subject to larger temperatures which makes the material more ductile. The speed of propagation of the elasto-plastic boundary is calculated and its acceleration towards the surface of the fault may be indicative of a dynamic earthquake type event.
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Aramphongphun, Chuckaphun. "In-mold coating of thermoplastic and composite parts microfluidics and rheology /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1141759615.
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Aubry, Jérôme. "Séismes au laboratoire : friction, plasticité et bilan énergétique." Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEE053.
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Au sein de la lithosphère, la transition entre déformations fragile et plastique des roches s’effectue dans le régime semicassant. Comprendre le comportement des failles naturelles dans le régime semi-cassant est fondamental puisque d’importants séismes nucléent à la base de la zone sismogénique, à des conditions de pression et température proches de celles de la transition fragile-plastique. Pendant un séisme, l’énergie élastique accumulée lors de la période intersismique est dissipée au sein de l’interface de glissement par des processus frictionnels et de fracture, le reste étant relâché sous forme d’ondes sismiques. Ce budget énergétique est influencé par la déformation des surfaces de failles pendant des glissements lents à rapides, et plus particulièrement par des processus de chauffage, invisibles aux yeux de la sismologie. Afin d’étudier la déformation semi-cassante des roches et le budget énergétique des séismes, nous avons effectué des expériences de reproduction de séismes au laboratoire, en conditions triaxiales, à l’aide de failles expérimentales de différentes lithologies. Nous avons étudié l’influence de la pression, de la vitesse de déformation, de la température et de la rugosité sur la stabilité des failles le long de la transition fragile-plastique et exploré la dynamique des séismes au laboratoire en mesurant la quantité de chaleur produite sur une faille durant un cycle sismique. Deux conclusions principales émanent de ces travaux. D’abord, les séismes au laboratoire peuvent se déclencher au sein de roches déformées plastiquement dans le régime semi-cassant. Les glissements observés sont majoritairement contrôlés par la rugosité de la faille. Pour finir, lors d’un cycle sismique, les failles opèrent une transition depuis un stade avec de multiples aspérités radiant peu d’énergie, à un stade où elles évoluent comme une aspérité unique, radiant un maximum d’énergieIn the lithosphere, the transition from brittle to plastic rock deformation corresponds to the semi-brittle regime. Understand how natural faults behave in the semi-brittle regime is fundamental to explain why large earthquakes generally nucleate at the base of the seismogenic zone, found at pressure and temperature conditions close to the predicted brittle-plastic transition. During an earthquake, part of the released elastic strain energy stored during the interseismic period is dissipated within a fault slip zone by frictional and fracturing processes, the rest being radiated away via elastic waves. This energy balance is influenced by the deformation of fault surfaces during slow or fast sliding, especially by frictional heating processes which could not be resolved by seismology. To investigate semi-brittle deformation and the energy balance of natural earthquakes, we performed laboratory earthquakes in triaxial conditions on experimental faults of various lithologies. We studied the influence of the confining pressure, axial loading rates, temperature and fault roughness on fault stability across the brittle-plastic transition and investigate the dynamics of laboratory earthquakes by measuring frictional heat dissipated during the propagation of shear instabilities. The main conclusions are twofold. First, laboratory earthquakes may nucleate on inherited fault interfaces at brittle-plastic transition conditions and fault slip behavior is mainly influenced by roughness. Second, we conclude that during sliding, faults exhibit a transition from a weak stage with multiple strong asperities and little overall radiation, to a highly radiative stage during which the fault behaves as a single strong asperity
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Hosseinzadeh, Delandar Arash. "Numerical Modeling of Plasticity in FCC Crystalline Materials Using Discrete Dislocation Dynamics." Licentiate thesis, KTH, Materialteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-175424.
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Plasticity in crystalline solids is controlled by the microscopic line defects known as “dislocations”. Decisive role of dislocations in crystal plasticity in addition to fundamentals of plastic deformation are presented in the current thesis work. Moreover, major features of numerical modeling method “Discrete Dislocation Dynamics (DDD)” technique are described to elucidate a powerful computational method used in simulation of crystal plasticity. First part of the work is focused on the investigation of strain rate effect on the dynamic deformation of crystalline solids. Single crystal copper is chosen as a model crystal and discrete dislocation dynamics method is used to perform numerical uniaxial tensile test on the single crystal at various high strain rates. Twenty four straight dislocations of mixed character are randomly distributed inside a model crystal with an edge length of 1 µm subjected to periodic boundary conditions. Loading of the model crystal with the considered initial dislocation microstructure at constant strain rates ranging from 103 to 105s1 leads to a significant strain rate sensitivity of the plastic flow. In addition to the flow stress, microstructure evolution of the sample crystal demonstrates a considerable strain rate dependency. Furthermore, strain rate affects the strain induce microstructure heterogeneity such that more heterogeneous microstructure emerges as strain rate increases. Anisotropic characteristic of plasticity in single crystals is investigated in the second part of the study. Copper single crystal is selected to perform numerical tensile tests on the model crystal along two different loading directions of [001] and [111] at two high strain rates. Effect of loading orientation on the macroscopic behavior along with microstructure evolution of the model crystal is examined using DDD method. Investigation of dynamic response of single crystal to the mechanical loading demonstrates a substantial effect of loading orientation on the flow stress. Furthermore, plastic anisotropy is observed in dislocation density evolution such that more dislocations are generated as straining direction of single crystal is changed from [001] to [111] axis. Likewise, strain induced microstructure heterogeneity displays the effect of loading direction such that more heterogeneous microstructure evolve as single crystal is loaded along [111] direction. Formation of slip bands and consequently localization of plastic deformation are detected as model crystal is loaded along both directions.QC 20151015
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Koran, François. "Anomalous wall slip behavior of linear low density polyethylenes." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26394.
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It is becoming generally accepted that wall slip, the loss of adhesion of a polymer to a solid substrate, occurs when the shear stress exceeds a critical value. Wall slip probably plays a much more important role in plastics processing than has been previously thought. For example, the extrudate distortion called sharkskin is thought to involve slip. Recent experiments have shown that this phenomenon is highly material dependant. The surface chemistry of both the molten polymer and the bounding surface interface play important roles in both the occurrence and magnitude of wall slip. The initial objectives of the research were to study slip in further detail, concentrating on the effects of the molecular weight and molecular weight distribution of the polymer. The effects of surface properties were also to be investigated. The research was performed using a sliding plate rheometer. Erratic stress signals were observed when the shear stress exceeded a critical level, and there was strong evidence that these were related to a highly complex type of slip. Thus, a steady slip velocity, which could be simply related to the shear stress, could not be determined. It was concluded that wall slip is, in general, a chaotic process with a strong dependence on initial conditions, sample history, and boundary conditions. Further research is suggested to elucidate this phenomenon.
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Hatzikiriakos, Savvas Georgios. "Wall slip of linear polyethylenes and its role in melt fracture." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=70285.
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Experiments were performed in a sliding plate rheometer and in capillaries and slits with several polymer melts, particularly polyethylenes, to determine the conditions for the onset of slip and melt fracture. In the sliding plate rheometer various shear tests were used to determine the relationship between the slip velocity and wall shear stress, and based on the experimental observations both steady state and dynamic slip models are proposed that are consistent with experimental observations. In the capillary flow studies the dependence of the slip velocity on wall shear stress, pressure, temperature and molecular parameters of molten polyethylenes was studied and the results were used to formulate a general slip velocity model. Because the slip velocity depends on pressure and thus varies with position in capillary flow, the Mooney procedure in determining the slip velocity is not appropriate. A modified Mooney technique is proposed to analyse the capillary data in cases where the slip velocity is a function of both wall shear stress and pressure. Using the slip velocity model, the steady state and unsteady state equation of motion was solved in capillary flow, and the calculated results were found to agree with the experimental results to a satisfactory degree. The oscillating flow regime was studied in detail, and the slip flow model was found to predict several features of this flow regime very well. Finally, the effect of interface conditions (surface coatings and metal of construction of slits) on both wall slip and melt fracture was studied.
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Sentmanat, Martin Lamar. "The effect of pressure on the wall slip of linear polyethylene." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39998.
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Experiments were performed on a slit die rheometer to determine the effect of pressure on the wall slip of linear polyethylene. A novel shear stress transducer was developed to measure local wall shear stress at several locations along the die. It was found that above the critical shear stress for the onset of slip, the shear stress distribution along the die was nonuniform. Furthermore, it was discovered that the local wall shear stress near the exit of the die was greater than the nominal, or length-averaged, shear stress within the die as calculated from the pressure drop. Teflon$ sp circler$ wall coatings were used to promote slip by lowering the critical shear stress for the onset of slip. Relative local slip velocities were calculated and found to be a function of pressure and wall shear stress.A new semi-empirical model for the pressure dependence of slip was developed based on the effect of pressure on the work of adhesion and the work needed for flow. The new model indicates that pressure can both suppress and promote slip depending on the level of stress involved. At low pressures, and for a given shear stress, slip is markedly suppressed due to the increase in the work of adhesion. As pressure increases, however, the work needed for flow overcomes the work of adhesion, and slip dramatically increases. However, at higher pressure, the effect of pressure on slip becomes weaker. Numerical simulation results with the new model predict the existence of a local maximum in the shear stress distribution along the die for flow with slip.
Books on the topic "Plastic slip"
1
inc, Transmission Research, and Lewis Research Center, eds. Rolling, slip, and endurance traction measurements on low modulus materials. Cleveland OH: National Aeronautics and Space Administration, Lewis Research Center, 1985.
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Bayerschen, Eric. Single-crystal Gradient Plasticity With an Accumulated Plastic Slip: Theory and Applications. Saint Philip Street Press, 2020.
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Bayerschen, Eric. Single-crystal Gradient Plasticity With an Accumulated Plastic Slip: Theory and Applications. Saint Philip Street Press, 2020.
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Steigmann, David J. Elements of plasticity theory. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198567783.003.0013.
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Chapter 13 develops the modern theory for finite elastic-plastic deformations. It covers dissipation and highlights the role of the Eshelby tensor, and recovers the classical theory for isotropic materials using material symmetry arguments. Also developed are the equations of classical slip-line theory for plane-strain deformations.
Book chapters on the topic "Plastic slip"
1
Ohashi, Tetsuya. "Dislocation Accumulation Due to Plastic Slip." In Synthesis Lectures on Mechanical Engineering, 7–24. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-37893-5_3.
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Lagerlöf, K. P. D. "Basal Slip and Twinning in Sapphire (α-Al2O3)." In Plastic Deformation of Ceramics, 63–74. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4899-1441-5_6.
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Cordier, Patrick. "6. Dislocations and Slip Systems of Mantle Minerals." In Plastic Deformation of Minerals and Rocks, edited by Shun-ichiro Karato and Hans-Rudolph Wenk, 137–80. Berlin, Boston: De Gruyter, 2002. http://dx.doi.org/10.1515/9781501509285-010.
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Kobayashi, Michiaki. "Ultrasonic Nondestructive Evaluation of Micro Slip Band and Plastic Anisotropy Growth." In Anisotropy and Localization of Plastic Deformation, 143–47. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3644-0_33.
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Havner, K. S. "G. I. Taylor Revisited: The Cone of Unextended Directions in Double Slip." In Anisotropy and Localization of Plastic Deformation, 315–18. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3644-0_73.
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Teng, Hao, Hailang Wan, and Junying Min. "Experimental Study on the Cohesive Model of Steel-Carbon Fiber Reinforced Plastic Interface by Laser Treatment." In Lecture Notes in Mechanical Engineering, 853–63. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-1876-4_67.
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AbstractThe interfacial bonding performance between steel and CFRP significantly influences the mechanical properties of steel-CFRP hybrid structures. Surface treatment is commonly employed to enhance the bonding interface of steel-CFRP. Laser surface treatment is particularly advantageous due to its high efficiency, automatic production capabilities, and widespread use in enhancing interfacial bonding performance. However, little attention has been given to the impact of laser surface treatment on the property parameters that describe the cohesive mode's mechanical behavior at the steel-CFRP interface. This study examined the cohesive zone modes of both original and laser-treated steel-CFRP joints through a double lap shear test following ASTM D3528-96 (2016) standards. Non-contact strain measurement was conducted using 3D digital image correlation techniques. The analysis indicates that the bilinear cohesive model effectively describes the mechanical behavior of the steel-CFRP interface. Laser surface treatment resulted in a respective increase of 83.8% in maximum shear strength, 111.6% in the relative slip corresponding to maximum shear strength and 116.8% in maximum relative slip. Consequently, this study showcases the efficacy of laser surface treatment in improving the mechanical performance at the steel-CFRP interface while quantitatively assessing these improvements through performance parameters within the cohesive zone model.
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Tsuru, Tomohito. "Descriptions of Dislocation via First Principles Calculations." In The Plaston Concept, 91–115. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7715-1_5.
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AbstractDislocation is one of the most representative plastons to determine the mechanical properties of crystalline materials. In this section, several computational approaches for of dislocations and dislocation-related properties are introduced within the framework of first principles calculations. The staking fault energy corresponding to the local interfacial misfit energy is one of the most important characteristics to determine the shape and motion of dislocations. The first principles calculations of the staking fault energy on various slip planes in HCP metals are provided compared with several materials. Peierls–Nabarro model is then introduced to describe the shape and motion of the dislocation. Finally, atomic configuration of a dislocation dipole in a periodic cell can be modeled based on the linear elasticity theory. First principles calculations are thus directly applied to dislocation core structure which enable us to evaluate the effect of solute element on the dislocation core structure and motion.
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Tochigi, Eita, Bin Miao, Shun Kondo, Naoya Shibata, and Yuichi Ikuhara. "TEM Characterization of Lattice Defects Associated with Deformation and Fracture in α-Al2O3." In The Plaston Concept, 133–56. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7715-1_7.
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AbstractAlumina (α-Al2O3) is one of the representative structural ceramics. To understand its mechanical responses, the lattice defect behavior of alumina has been investigated by transmission electron microscopy (TEM) for many years. In this report, we review our recent research progress on TEM structural analysis of lattice defects in alumina. In the first half, the core atomic structure and dissociation reaction of b = $$1/3<11\bar{2}0>$$ 1 / 3 < 11 2 ¯ 0 > , $$<1\bar{1}00>$$ < 1 1 ¯ 00 > , and $$1/3<\bar{1}101>$$ 1 / 3 < 1 ¯ 101 > dislocations formed in low-angle grain boundaries are investigated by atomic-resolution TEM observations. Based on experimental results, the slip deformation behavior associated with those dislocations is discussed. In the second half, the formation of $$1/3<11\bar{2}0>$$ 1 / 3 < 11 2 ¯ 0 > dislocations and fracture of Zr-doped ∑13 grain boundary of alumina are observed by in situ TEM nanoindentation. Furthermore, these indented samples were observed by atomic-resolution scanning TEM. The mechanisms of the deformation and fracture phenomena are discussed in detail.
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Tsuji, Nobuhiro, Shigenobu Ogata, Haruyuki Inui, Isao Tanaka, and Kyosuke Kishida. "Proposing the Concept of Plaston and Strategy to Manage Both High Strength and Large Ductility in Advanced Structural Materials, on the Basis of Unique Mechanical Properties of Bulk Nanostructured Metals." In The Plaston Concept, 3–34. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7715-1_1.
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AbstractAdvanced structural materials are required to show both high strength and large ductility/toughness, but we have not yet acquired the guiding principle for that. The bulk nanostructured metals are polycrystalline metallic materials having bulky dimensions and average grain sizes smaller than 1 μm. Bulk nanostructured metals show very high strength compared with that of the coarse-grained counterparts, but usually exhibit limited tensile ductility, especially small uniform elongation below a few %, due to the early plastic instability. On the other hand, we have recently found that particular bulk nanostructured metals can manage high strength and large tensile ductility. In such bulk nanostructured metals, unusual deformation modes different from normal dislocation slips were unexpectedly activated. Unusual <c+a> dislocations, deformation twins with nano-scale thickness, and deformation-induced martensite nucleated from grain boundaries in the bulk nanostructured Mg alloy, high-Mn austenitic steel, and Ni-C metastable austenitic steel, respectively. Those unexpected deformation modes enhanced strain hardening of the materials, leading to high strength and large tensile ductility. It was considered that the nucleation of such unusual deformation modes was attributed to the scarcity of dislocations and dislocation sources in each recrystallized ultrafine grain, which also induced discontinuous yielding with clear yield drop universally recognized in bulk nanostructured metals having recrystallized structures. For discussing the nucleation of different deformation modes in atomistic scales, the new concept of plaston which considered local excitation of atoms under singular dynamic fields was proposed. Based on the findings in bulk nanostructured metals and the concept of plaston, we proposed a strategy for overcoming the strength-ductility trade-off in structural metallic materials. Sequential nucleation of different deformation modes would regenerate the strain-hardening ability of the material, leading to high strength and large tensile ductility. The strategy could be a guiding principle for realizing advanced structural materials that manage both high strength and large tensile ductility.
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Hill, Ryan E., and Julian J. Eaton-Rye. "Plasmid Construction by SLIC or Sequence and Ligation-Independent Cloning." In DNA Cloning and Assembly Methods, 25–36. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-764-8_2.
Full textConference papers on the topic "Plastic slip"
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Harris, David, Joe Goddard, Pasquale Giovine, and James T. Jenkins. "The Plastic Potential, Double-slip, Double-spin and Viscoplasticity." In IUTAM-ISIMM SYMPOSIUM ON MATHEMATICAL MODELING AND PHYSICAL INSTANCES OF GRANULAR FLOWS. AIP, 2010. http://dx.doi.org/10.1063/1.3436466.
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Ovcharenko, Andrey, and Izhak Etsion. "Very Early Stage of Elastic-Plastic Spherical Contact Fretting." In ASME/STLE 2009 International Joint Tribology Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/ijtc2009-15031.
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The contact area, friction force and relative displacement evolution at the very early stage of fretting are investigated experimentally. Copper and steel spheres of various diameters are loaded against a hard sapphire flat by a range of normal loads deep into the elastic-plastic regime of deformation. A reciprocating tangential loading is then applied with a maximum loading below the static friction to avoid gross slip. Real-time and in situ direct measurements of the contact area, along with accurate measurements of the friction force and relative displacement, reveal substantial junction growth and energy dissipation mainly in the first loading cycle. The so called “slip amplitude” is found to be attributed to residual tangential plastic deformation rather than to interfacial slip. Elastic shake-down is observed for the 2.5% hardening steel spheres while plastic shake-down is observed in the case of the elastic perfectly plastic copper spheres.
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Seiner, Hanuš, Petr Sedlák, Miroslav Frost, and Petr Šittner. "Kwink Patterns in Plastically Formed NiTi Martensite." In SMST 2024. ASM International, 2024. http://dx.doi.org/10.31399/asm.cp.smst2024p0029.
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Abstract Nickel-titanium B19’ martensite is a strongly plastically anisotropic material with only one available slip system, which is the [100](001)M slip. Despite this, B19’ martensite polycrystals can be homogeneously plastically formed, reaching up to very high plastic strains. The absence of other slip systems is compensated by plastic twinning, in particular by the frequently appearing irreversible (20-1)M twins. However, these twins act on the same (010)M lattice plane as the plastic slip, and thus, do not seem to be a very suitable complement to the slip in terms of the Von Mises criterion. In fact, exactly the same strains as by the (20-1)M twins can be achieved also by the [100](001)M slip itself, and thus, a question arises, whether they can be understood as plastic twins in the conventional sense.
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McClintock, F. A., K. L. Kenney, S. Jung, W. G. Reuter, and D. M. Parks. "Asymmetric, Fully Plastic Crack Growth Mechanics and Tests for Structures and Piping." In ASME 1996 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/imece1996-0570.
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Abstract Many structures damaged in recent earthquakes had cracks from welds that broke the flanges of beams, broke flanges from columns, or veered off, sometimes through columns. At least some structures were fully plastic during crack growth.. A complete asymmetric, plane strain, non-hardening, isotropic, rigid-plastic fracture mechanics is developed to predict such asymmetric crack growth from small specimen tests. For short cantilever specimens with an EDM slot across from an offset shoulder, slip line fields give the three crack tip driving parameters: a slip direction 58° to 77° from the transverse (loading) direction, a moderate mean normal stress, and a slip of about half the applied displacement. Tests on A710 steel, TS = 630 MPa, gave the crack tip growth responses at that mean normal stress: cracking within 4° of the observed slip direction and growth per unit slip of 3 to 5, somewhat low compared to other configurations and materials.
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Alexandrov, Sergei. "Steady Planar Ideal Plastic Flows for the Double Slip and Rotation Model." In Sixth Biot Conference on Poromechanics. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784480779.120.
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Aurongzeb, Deeder. "Porous oxide nanostructure with spiral staircase formed by discrete cross plastic slip." In NanoScience + Engineering, edited by Zeno Gaburro, Stefano Cabrini, and Dmitri Talapin. SPIE, 2008. http://dx.doi.org/10.1117/12.800601.
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Wijeyeratne, Navindra, Firat Irmak, Ali P. Gordon, and Jun-Young Jeon. "Crystal Visco-Plastic Model for Ni-Base Superalloys Under Thermomechanical Fatigue." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14163.
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Abstract Gas turbine blades are subjected to complex mechanical loading coupled with extreme thermal loading conditions which range from room temperature to over 1000°C. Nickel-base superalloys exhibit high strength, good resistance to corrosion and oxidation, long fatigue life and is capable of withstanding high temperatures for extended periods of time. Consequently, Ni-base superalloys (NBSAs) are highly suitable as blading materials. The cyclic strains due to mechanical as well as thermal cycling leads to Thermomechanical fatigue (TMF). Damage from TMF takes the form of microstructural material cracking which consequently lead to the failure of the component. In order to increase the service life and reliability and reduce operating costs, development of simulations that accurately predict the material behavior for TMF is highly desirable. To support the mechanical design process, a framework consisting of theoretical mechanics, experimental analysis and numerical simulations must be used. Capturing the effects of thermomechanical fatigue is extremely important in the prediction of the material behavior and life expectation. Single crystal (SX) Ni-base superalloys exhibit anisotropic behavior. A modeling framework which is capable of simulating the physical attributes of the material microstructure is essential. Crystallographic slip along the slip planes controls the microstructural evolution of the material Crystal Visco-Plasticity (CVP) theory captures anisotropic behavior as well as the slip along the slip planes. CVP constitutive models can capture rate-, temperature, and history-dependence of these materials under a variety of conditions. Typical CVP formulations consist of a flow rule, internal state variables, and parameters. The model presented in the current study includes the inelastic mechanism of kinematic hardening and isotropic hardening which are captured by the back stress and drag stress, respectively. Crystallographic slip is accounted for by the incorporation of twelve octahedral six cubic slip systems. An implicit integration scheme which uses Newton-Raphson iteration method is used to solve the required solutions. The CVP model is implemented through a general-purpose finite element analysis software (i.e., ANSYS) as a User-Defined Material (USERMAT). A small batch of uniaxial experiments were conducted in key orientations (i.e., [001], [011], and [111] to assess the level of elastic and inelastic anisotropy. Modeling parameters are expressed as temperature-dependent to allow for simulation under non-isothermal conditions. An optimization scheme based in MATLAB utilizes this experimental data to calibrate the CVP modeling constants. The CVP model has the capability to simulate material behavior for monotonic and cyclic loading coupled with in phase and out phase temperature cycling for a variety of material orientations, strain rates, strain and temperature ranges. A CVP model that predicts SX behavior across various rates, orientations, temperatures and load levels have not been presented before now.
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Ancelet, O., Ph Gilles, P. Le Delliou, and G. Perez. "Ductile Tearing and Plastic Collapse Competition." In ASME 2020 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/pvp2020-21853.
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Abstract Structures containing large cracks and made in ductile materials may experience two types of failure mechanisms: ductile tearing or plastic collapse. Under displacement controlled loading ductile tearing is a stable crack growth mechanism. Plastic collapse leads to a much faster damage evolution. Ductile tearing is the result of void growth and coalescence ahead of the crack front under the high strain concentration. This mechanism is slowed down by a high material hardening and under a high constraint. The global deformation of the structure is limited. Plastic collapse is induced by plastic strain accumulation along slip lines. Slip lines depend on the geometry of the cracked structures and of the type of loading. Therefore plastic collapse produces large deformations of the structure. Several studies (Nicak, 2009; Gilles, 2010; Le Delliou, 2017) on large ductile crack growth have been performed by Framatome, and EDF on deeply surface cracked plates made in Nickel base alloy 600. The tests were performed on Centre Cracked Tension specimens with a semi-elliptical surface crack. In this very tough material, the crack grew in its plane, but for large load levels, the plate was extremely deformed and a collapse mechanism appeared. More recently, Tests on Fixed Grip SE(T) specimens in Nickel base alloy 600 were performed by CEA showing a different type of transition between ductile tearing to collapse in function of the crack length. The paper analyzes these experiments and simulates the ductile tearing using node release methodology. The prediction of the apparition of the collapse is obtained by determining collapse load with large displacement modeling. From these results, a reconciliation of curves J-R of the CCT et SE(T) specimen will be done.
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Chen, Yung-Chuan, and Jao-Hwa Kuang. "Elastic-Plastic Partial Slip Rolling Wheel-Rail Contact With an Oblique Rail Crack." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-59379.
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The effect of rail surface crack on the wheel-rail contact pressure distribution under partial slip rolling was studied in this work. The elastic-plastic finite element model was employed for stress analyses. The numerical simulations were used to explore the effects of the contact distances and tractive force on the normal and tangential contact pressure distributions, tip plastic energy and critical wheel applied load. Contact elements were used to simulate the interaction between wheel and rail and crack surfaces. Numerical results indicate that the contact pressure distributions are significantly affected by the rail crack. Traditional contact theories are not available to describe the contact pressure distribution on the contact crack surfaces. Results also indicate that a higher friction force on the contact crack surfaces is observed for wheel subjected a larger tractive force. A larger crack surfaces friction force can reduce the sliding between crack surfaces and leads to a smaller tip plastic energy.
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Arakere, Nagaraj K., Shadab Siddiqui, Shannon Magnan, Fereshteh Ebrahimi, and Luis E. Forero. "Investigation of Three-Dimensional Stress Fields and Slip Systems for FCC Single Crystal Superalloy Notched Specimens." In ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-53938.
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Metals and their alloys, except for a few intermetallics, are inherently ductile, i.e. plastic deformation precedes fracture in these materials. Therefore, resistance to fracture is directly related to the development of the plastic zone at the crack tip. Recent studies indicate that the fracture toughness of single crystals depends on the crystallographic orientation of the notch as well as the loading direction. In general, the dependence of crack propagation resistance on crystallographic orientation arises from the anisotropy of (i) elastic constants, (ii) plastic deformation (or slip), and (iii) the weakest fracture planes (e.g. cleavage planes). Because of the triaxial stress state at the notch tips, many slip systems that otherwise would not be activated during uniaxial testing, become operational. The plastic zone formation in single crystals has been tackled theoretically by Rice and his co-workers [10–14] and only limited experimental work has been conducted in this area. The study of the stresses and strains in the vicinity of a FCC single crystal notch tip is of relatively recent origin. We present experimental and numerical investigation of 3D stress fields and evolution of slip sector boundaries near notches in FCC single crystal PWA1480 tension test specimens, and demonstrate that a 3D linear elastic finite element model that includes the effect of material anisotropy is shown to predict active slip planes and sectors accurately. The slip sector boundaries are shown to have complex curved shapes with several slip systems active simultaneously near the notch. Results are presented for surface and mid-plane of the specimens. The results demonstrate that accounting for 3D elastic anisotropy is very important for accurate prediction of slip activation near FCC single crystal notches loaded in tension. Results from the study will help establish guidelines for fatigue damage near single crystal notches.
Reports on the topic "Plastic slip"
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Sanders, John, and Grant Davidson. Wet Slip Resistance of Plastic Based Material Flooring (PBM Flooring). Clemson University, December 2019. http://dx.doi.org/10.34068/report.01.
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Addessio, Francis L., Curt Allan Bronkhorst, Cynthia Anne Bolme, Donald William Brown, Ellen Kathleen Cerreta, Ricardo A. Lebensohn, Turab Lookman, et al. A High-Rate, Single-Crystal Model including Phase Transformations, Plastic Slip, and Twinning. Office of Scientific and Technical Information (OSTI), August 2016. http://dx.doi.org/10.2172/1312644.
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Underwood, J. H., J. J. Keating, E. Troiano, and A. P. Parker. Expression for Calculating Plastic Radius, c, from Slit Opening of a Disk from an Autofrettaged Tube. Fort Belvoir, VA: Defense Technical Information Center, November 2010. http://dx.doi.org/10.21236/ada589992.
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Tao, Yang, Amos Mizrach, Victor Alchanatis, Nachshon Shamir, and Tom Porter. Automated imaging broiler chicksexing for gender-specific and efficient production. United States Department of Agriculture, December 2014. http://dx.doi.org/10.32747/2014.7594391.bard.
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Extending the previous two years of research results (Mizarch, et al, 2012, Tao, 2011, 2012), the third year’s efforts in both Maryland and Israel were directed towards the engineering of the system. The activities included the robust chick handling and its conveyor system development, optical system improvement, online dynamic motion imaging of chicks, multi-image sequence optimal feather extraction and detection, and pattern recognition. Mechanical System Engineering The third model of the mechanical chick handling system with high-speed imaging system was built as shown in Fig. 1. This system has the improved chick holding cups and motion mechanisms that enable chicks to open wings through the view section. The mechanical system has achieved the speed of 4 chicks per second which exceeds the design specs of 3 chicks per second. In the center of the conveyor, a high-speed camera with UV sensitive optical system, shown in Fig.2, was installed that captures chick images at multiple frames (45 images and system selectable) when the chick passing through the view area. Through intensive discussions and efforts, the PIs of Maryland and ARO have created the protocol of joint hardware and software that uses sequential images of chick in its fall motion to capture opening wings and extract the optimal opening positions. This approached enables the reliable feather feature extraction in dynamic motion and pattern recognition. Improving of Chick Wing Deployment The mechanical system for chick conveying and especially the section that cause chicks to deploy their wings wide open under the fast video camera and the UV light was investigated along the third study year. As a natural behavior, chicks tend to deploy their wings as a mean of balancing their body when a sudden change in the vertical movement was applied. In the latest two years, this was achieved by causing the chicks to move in a free fall, in the earth gravity (g) along short vertical distance. The chicks have always tended to deploy their wing but not always in wide horizontal open situation. Such position is requested in order to get successful image under the video camera. Besides, the cells with checks bumped suddenly at the end of the free falling path. That caused the chicks legs to collapse inside the cells and the image of wing become bluer. For improving the movement and preventing the chick legs from collapsing, a slowing down mechanism was design and tested. This was done by installing of plastic block, that was printed in a predesign variable slope (Fig. 3) at the end of the path of falling cells (Fig.4). The cells are moving down in variable velocity according the block slope and achieve zero velocity at the end of the path. The slop was design in a way that the deacceleration become 0.8g instead the free fall gravity (g) without presence of the block. The tests showed better deployment and wider chick's wing opening as well as better balance along the movement. Design of additional sizes of block slops is under investigation. Slops that create accelerations of 0.7g, 0.9g, and variable accelerations are designed for improving movement path and images.