A Simplified Large Thin Plate Model for Modeling Fracture Behavior of a Hydrided Irradiated Zr-2.5Nb Pressure Tube Specimen With an Axial Crack

2019 ◽  
Author(s):  
Shin-Jang Sung ◽  
Jwo Pan ◽  
Cheng Liu ◽  
Douglas A. Scarth
Keyword(s):  
Thin Plate ◽  
Crack Front ◽  
Pressure Tube ◽  
Upper And Lower Bounds ◽  
Plastic Strains ◽  
Plate Model ◽  
Constraint Condition ◽  
Symmetry Constraint ◽  
Modeling Fracture ◽  
Axial Crack

Abstract The crack tip opening displacements (CTODs) and the effective plastic strains ahead of the crack front in a hydrided irradiated Zr-2.5Nb pressure tube specimen with an axial crack are investigated using two 3-D finite element models in this paper. The first model is a pressure tube with 80 split circumferential hydrides distributed through the thickness ahead of the crack front. The second model is a large thin plate with a central crack with four split circumferential hydrides under symmetry/symmetry, free/symmetry and free/free constraint conditions. The results for CTOD indicate that the CTOD of the pressure tube specimen with 80 hydrides is slightly smaller than that for the large thin plate with the free/symmetry constraint condition and larger than that for the large thin plate with the symmetry/symmetry constraint condition. The effective plastic strain of the pressure tube specimen with 80 hydrides is smaller than that for the large thin plate with the free/symmetry constraint condition and larger than that for the large thin plate with the symmetry/symmetry constraint condition at large normalized loads. The computational results show that instead of modeling a full 3-D pressure tube with a larger number of hydrides, a large thin plate model with a limited number of hydrides can be used to efficiently determine the upper and lower bounds of the CTODs and the effective plastic strains ahead of the crack front in a pressure tube specimen.

scholarly journals On well-posedness of time-harmonic problems in an unbounded strip for a thin plate model

2019 ◽  
Vol 17 (6) ◽  
pp. 1487-1529 ◽  
Author(s):  
Laurent Bourgeois ◽  
Lucas Chesnel ◽  
Sonia Fliss
Keyword(s):  
Thin Plate ◽  
Well Posedness ◽  
Plate Model ◽  
Time Harmonic

Interpretation of borehole VLF logs: The thin plate model

1984 ◽  
Author(s):  
Robert Bazinet ◽  
Diane Couture
Keyword(s):  
Thin Plate ◽  
Plate Model

Strength Design of Reinforced Soil in the Front of Shield Departure Shaft

2011 ◽  
Vol 261-263 ◽  
pp. 1584-1588
Author(s):  
Xian Yang ◽  
Ke Neng Zhang
Keyword(s):  
Shear Strength ◽  
Thin Plate ◽  
Maximum Stress ◽  
Reinforced Soil ◽  
Shield Tunnel ◽  
Plate Model ◽  
Elastic Structures ◽  
Strength Design

In the construction of shield tunnel, the strength of reinforced soil in the front of departure shaft concerns directly the security of construction. Based on Mechanics of Elastic Structures theory, a thin plate model about reinforced soil is introduced, the maximum stress on reinforced soil is calculated. The security of strength in reinforced area is discussed. With the derived formulas, the needed bending and shear strength of reinforced soil in the project of Beijing Metro Line No. 4 is calculated beforehand, and appropriate material and construction parameters are selected in reinforcement according to the calculate result.

scholarly journals Error estimates for the unilateral buckling load of a plate involving the membrane efforts consistency error

2008 ◽  
pp. 1003-1038
Author(s):  
Mekki Ayadi
Keyword(s):  
Finite Elements ◽  
Error Estimate ◽  
Critical Load ◽  
Error Estimates ◽  
Thin Plate ◽  
Numerical Experiments ◽  
Mesh Size ◽  
Buckling Load ◽  
Plate Model ◽  
Consistency Error

The paper deals with error estimates for the unilateral buckling critical load of a thin plate in presence of an obstacle. The error on the membrane efforts tensor is taken into account. First, using the Mindlin’s plate model together with a finite elements scheme of degree one, an error estimate, depending on the mesh size h, is established. In order to validate this theoretical error estimate, some numerical experiments are presented. Second, using the Kirchhoff-Love’s plate model, an abstract error estimate is achieved. Its drawback is that it contains a hard term to evaluate.

Fracture Initiation in Pressure Tube Specimens of Hydrided Irradiated Zr-2.5Nb Materials With Split Circumferential Hydrides

2017 ◽  
Author(s):  
Shin-Jang Sung ◽  
Jwo Pan ◽  
Poh-Sang Lam ◽  
Douglas A. Scarth
Keyword(s):  
Crack Initiation ◽  
Crack Front ◽  
Room Temperature ◽  
Three Dimensional ◽  
Stress Triaxiality ◽  
Fracture Initiation ◽  
Pressure Tube ◽  
Computational Results ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Fracture initiation for axial cracks in pressure tube (PT) specimens of hydrided irradiated Zr-2.5Nb materials with split circumferential hydrides at room temperature is examined by conducting three-dimensional finite element analyses. With a strain-based fracture criterion with consideration of stress triaxiality, the location for the earliest crack initiation is determined near the middle of the axial crack front. For PT specimens with split circumferential hydrides, three types of strain concentration are observed in the ligaments ahead of the crack front. The computational results suggest that the internal pressure for crack initiation of hydrided irradiated PT specimens with many randomly distributed split circumferential hydrides needs only 55% to 70% of that for unhydrided irradiated PT specimens. The computational results can be used to explain the near 40% reduction of the fracture toughness at room temperature obtained from hydrided irradiated PT specimens when compared with that from unhydrided irradiated ones.

Prediction of the Plastic Fracture Mechanical Properties on Metallurgical Composite Bimetallic Tube with Axial Crack

2011 ◽  
Vol 467-469 ◽  
pp. 1367-1371 ◽  
Author(s):  
Li Yun Zheng ◽  
Chun Qiang Li ◽  
Li Hui Wang ◽  
Ya Feng Song
Keyword(s):  
Mechanical Properties ◽  
Crack Growth ◽  
Residual Strength ◽  
Crack Depth ◽  
Failure Stress ◽  
Pressure Tube ◽  
Tube Model ◽  
Element Analysis ◽  
Plastic Failure ◽  
Axial Crack

Based on the finite element analysis software ABAQUS, the CT specimens of bimetallic material and the metallurgical composite bimetallic pressure tube with axial crack were simulated on the fracture mechanical properties, after that the crack growth residual strength and the plastic failure stress of the metallurgical composite bimetallic pressure tube model were obtained. The results indicate that the crack growth residual strength generates near the crack tip and the crack growth residual strength of the pressure tube model is smaller than the CT specimens. Meanwhile, the plastic failure stress values obtained from the CT specimens and the pressure tube model are basically consistent with the theoretical calculative values. With the crack depth a increasing, the plastic failure stress values will be reduced. For the same crack depth, the plastic failure stress values of the pressure tube model are slightly lower than the CT specimens and the theoretical calculative values.

DETERMINATION OF FLUTTER DERIVATIVES OF BRIDGE DECKS BY COVARIANCE-DRIVEN STOCHASTIC SUBSPACE IDENTIFICATION

2011 ◽  
Vol 11 (01) ◽  
pp. 73-99 ◽  
Author(s):  
THARACH JANESUPASAEREE ◽  
VIROTE BOONYAPINYO
Keyword(s):  
Wind Tunnel ◽  
Thin Plate ◽  
Bridge Deck ◽  
Bridge Decks ◽  
Subspace Identification ◽  
Plate Model ◽  
Wind Tunnel Tests ◽  
Stochastic Subspace Identification ◽  
Derivatives Of ◽  
Flutter Derivatives

In this paper, the covariance-driven stochastic subspace identification technique (SSI-COV) was presented to extract the flutter derivatives of bridge decks from the buffeting test results. An advantage of this method is that it considers the buffeting forces and responses as inputs rather than as noises. Numerical simulations and wind tunnel tests of a streamlined thin plate model conducted under smooth flows by the free decay and the buffeting tests were used to validate the applicability of the SSI-COV method. Then, the wind tunnel tests of a two-edge girder blunt type of industrial-ring-road (IRR) bridge deck were conducted under smooth and turbulence flows. The flutter derivatives of the thin plate model identified by the SSI-COV technique agree well with those obtained theoretically. The results obtained for the thin plate and the IRR bridge deck are used to validate the reliability and applicability of the SSI-COV technique to various wind tunnel tests and conditions of wind flows. The results also show that for the blunt-type IRR bridge deck, the turbulence wind will delay the onset of flutter, compared with the smooth wind.

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