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Showing 1 to 20 of 56 for “"critical stress"”.
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Investigation of induced strain actuator patches implementing modeling techniques and design considerations to reduce critical stress
… actuator (ISA) patches are the considerably high stress gradients introduced at the edges of the actuator patches when an electric field is applied. These excessive stress gradients initiate debonding of the actuators from the substrate, thus affecting the mechanical reliability of the structure. …
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Understanding the Stability of Retained Austenite in High-Carbon Steels: Modelling and Alloy Design
… transformation under applied stress initiates at a critical value, contrary to low-carbon steels where the transformation occurs at the early stages of deformation. There are few models that account for the delayed transformation, because previous models were mostly developed …
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Αστοχία ρηγματομένων όλκιμων πλακών με δύο συμμετρικές εγκοπές
… Based on the strain energy density criterion the critical stress for crack growth initiation is determined. The influence of body geometry as it is dictated by notch radius, crack length and distance between crack and notches on the critical stress is studied and important results are established. …
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Fracture of Hot-Pressed Silicon Nitride at Elevated Temperatures
… point bend at three displacement rates. Fracture stress and critical stress intensity factor were calculated and plotted versus temperature for each displacement rate. The scanning electron microscope, transmission electron microscope and scanning Auger electron spectrometer were used to analyze …
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Morphology Development and Fracture Properties of Toughened Epoxy Thermosets
… did not change with cure temperature, the critical stress intensity factor did not vary significantly with cure temperature as expected. However, increases in cure temperature produced smaller but more numerous particles. The critical stress intensity factor normalized by the number density …
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A method of testing stress-corrosion cracking in magnesium alloy FS-1 extruded bar
… susceptibility to various forms of corrosion. Stress-corrosion cracking, occurring under conditions of residual fabrication stresses or high external stresses, is a severe localized corrosion type which can bring about complete failure in most wrought magnesium alloys. Previous investigations …
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Plasticity as a depinning phase transition
… crystal (PFC) model in two dimensions. Below a critical ( ow) stress, the dislocations are pinned/jammed within their glide plane due to long-range elastic interactions and the material exhibits plastic response. Above this critical stress the dislocations are mobile (the depinned/ unjammed …
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Global-local Finite Element Fracture Analysis of Curvilinearly Stiffened Panels and Adhesive Joints
… cracks to be defined in the vicinity of the critical stress zone. With the damage tolerance study of unitized structures as the focus, responses of curvilinearly stiffened panels to the combined shear and compression loadings were studied for different stiffeners' height. It was observed that …
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Tensile Fracture Mechanisms of Ferritic/martensitic Structural Materials
… the hypothesis of the association between critical stress and critical interfacial strength, but also offer a new method to determine the true strain/stress behavior during deformation. This method is called the Universal Micro-structural Geometry-corrected Model (UMGM) in this …
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Modeling of twinning as a deformation mechanism in iron (bcc) crystals and iron-based alloys
… an analytical expression for twin nucleation stress in bcc metals considering GPFE (generalized planar fault energy) and the dislocations bounding the twin nucleus. We minimize the total energy to predict the twinning stress relying only on parameters that are obtained through atomistic …
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Fracture characterization of clays and clay-like materials using flattened Brazilian Test
… tool in studying fracture in rock, is the critical stress intensity factor that defines stress concentration near a crack tip beyond which a fracture would propagate. The basic mode of crack loading can be obtained by applying a normal stress that has a corresponding opening mode of crack …
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An Investigation of Classical Panel Stiffener Buckling Methods for Modern Airframe Applications
… of sizing bulb-stiffeners to achieve the highest critical stress obtainable by the web, and verify the two sizing procedures theoretically and using Finite Element Analysis software. The results suggest that the theoretical approach presented by Windenburg is correct as stated; however the FEA …
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Simulação do colapso progressivo da seção mestra de um navio militar devido à flexão longitudinal
… percentage differences between the last buckling stress of the different stiffness and those obtained in the buckling of the profiles and plates were also obtained. The results were 18% and 23% of differences in sagging and hogging, respectively. The overall average difference between the critical …
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Mechanics of planar periodic microstructures
… in pattern in the structure upon reaching a critical stress during compression. Experimental and numerical results are obtained that show the ability to predict and control the pattern changes that are triggered. The shape of the pattern change, the areas of the lattice in which it is …
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Experimental and seismological constraints on the rheology, evolution, and alteration of the lithosphere at oceanic spreading centers
… rates are linearly dependent on effective mean stress when the effective mean stress is low and non-linearly dependent on effective mean stress when it is high. Microearthquakes recorded above an inferred magma reservoir along the TAG segment of the Mid-Atlantic Ridge delineate for the first …
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Stress corrosion cracking and hydrogen embrittlement of thick section high strength low alloy steel
… Navy for use in ship structural applications. Stress corrosion CRACKING(SCC) and hydrogen embrittlement(HEM) were investigated by conducting 42 Wedge-Opening load(WOL) tests as a function of stress intensity and corrosion potential and 33 Slow Strain Rate(SSR) tests as a function of strain rate …
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A Bio-Inspired Self-Healing Polymer System for Sustainable Plastics
… stimuli and energy. This work investigates the critical stress intensity for propagating preexisting cracks induced by a Vickers indentation in P[3,4-DHS-S], and the effects that different cross-linking agents have on crack growth within the polymer matrix. A Life Cycle Assessment (LCA) is also …
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The mechanical properties of tightly woven carbon-carbon composites
… ± 5.9 MPa in argon at room temperature. The critical stress intensity factors, K1c, of these composites are 4.4 ± 0.2 MPa.m·112 in air and 4.5 ± o.2 MPa.m<sup>·1/2</sup> in argon at room temperature.</p> <p>The cyclic fatigue behavior of these composites was investigated as a function of …
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Fiber Orientation Effects on the Fracture and Flexural Toughness of Extruded Fiber Reinforced Concrete for Additive Manufacturing
… since they are aligned parallel to the tensile stresses produced in flexure testing. The FRCC employed 0.5% and 1% polyvinyl alcohol (PVA) fiber reinforcement by volume. The flexural properties of FRCC were determined using four-point bend tests according to a modified ASTM C1609. Calculations …
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Experimental and seismological constraints on the rheology, evolution, and alteration of the lithosphere at oceanic spreading centers
… rates are linearly dependent on effective mean stress when the effective mean stress is low and non-linearly dependent on effective mean stress when it is high. Microearthquakes recorded above an inferred magma reservoir along the TAG segment of the Mid-Atlantic Ridge delineate for the first …
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