Thermal Stresses During Solidification on Basis of Elastic Model

1969 ◽  
Vol 36 (4) ◽  
pp. 763-767 ◽  
Author(s):  
R. H. Tien ◽  
V. Koump
Keyword(s):  
Young’S Modulus ◽  
Thermal Stresses ◽  
Young's Modulus ◽  
Linear Thermal Expansion ◽  
Solidification Process ◽  
Elastic Model ◽  
Transverse Displacement ◽  
Temperature Dependent ◽  
Simply Supported ◽  
Horizontal Beam

Distributions of stress and displacement in a slab during a solidification process are obtained analytically using the model of an elastic horizontal beam with temperature-dependent Young’s modulus. Both simply supported and built-in ends are considered as the boundary condition for the beam. In addition to the physical properties such as coefficient of linear thermal expansion, density, expression of Young’s modulus, etc., the main parameters determining the stress and displacement involve the mode of cooling at the surface and the external force acting on the liquid-solid interface such as the hydrostatic head from liquid side. Some specific results are presented to illustrate the effect of cooling rate and the dimensions of the beam on development of thermal stress and transverse displacement during solidification of iron.

Size- and temperature-dependent Young's modulus and size-dependent thermal expansion coefficient of thin films

2016 ◽  
Vol 18 (31) ◽  
pp. 21508-21517 ◽  
Author(s):  
Xiao-Ye Zhou ◽  
Bao-Ling Huang ◽  
Tong-Yi Zhang
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Young’S Modulus ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Material Properties ◽  
Essential Role ◽  
Young's Modulus ◽  
Temperature Dependent ◽  
Size Dependent

Surfaces of nanomaterials play an essential role in size-dependent material properties.

scholarly journals Viscosity and elasticity: a model intercomparison of ice-shelf bending in an Antarctic grounding zone

2017 ◽  
Vol 63 (240) ◽  
pp. 573-580 ◽  
Author(s):  
CHRISTIAN T. WILD ◽  
OLIVER J. MARSH ◽  
WOLFGANG RACK
Keyword(s):  
Young’S Modulus ◽  
Ocean Circulation ◽  
Young's Modulus ◽  
Viscoelastic Model ◽  
Ice Sheet ◽  
Global Ocean ◽  
Elastic Model ◽  
Ice Shelf ◽  
Bending Stresses ◽  
Global Ocean Circulation

ABSTRACTGrounding zones are vital to ice-sheet mass balance and its coupling to the global ocean circulation. Processes here determine the mass discharge from the grounded ice sheet, to the floating ice shelves. The response of this transition zone to tidal forcing has been described by both elastic and viscoelastic models. Here we examine the validity of these models for grounding zone flexure over tidal timescales using field data from the Southern McMurdo Ice Shelf (78° 15′S, 167° 7′E). Observations of tidal movement were carried out by simultaneous tiltmeter and GPS measurements along a profile across the grounding zone. Finite-element simulations covering a 64 d period reveal that the viscoelastic model fits best the observations using a Young's modulus of 1.6 GPa and a viscosity of 1013.7 Pa s (≈ 50.1 TPa s). We conclude that the elastic model is only well-constrained for tidal displacements >35% of the spring-tidal amplitude using a Young's modulus of 1.62 ± 0.69 GPa, but that a viscoelastic model is necessary to adequately capture tidal bending at amplitudes below this threshold. In grounding zones where bending stresses are greater than at the Southern McMurdo Ice Shelf or ice viscosity is lower, the threshold would be even higher.

Analytical Solutions of Stresses in Functionally Graded Circular Hollow Cylinder with Finite Length

2004 ◽  
Vol 261-263 ◽  
pp. 651-656 ◽  
Author(s):  
Z.S. Shao ◽  
L.F. Fan ◽  
Tie Jun Wang
Keyword(s):  
Young’S Modulus ◽  
Hollow Cylinder ◽  
Finite Length ◽  
Analytical Solutions ◽  
Radial Direction ◽  
Young's Modulus ◽  
Functionally Graded ◽  
Numerical Results ◽  
Stress Fields ◽  
Simply Supported

Analytical solutions of stress fields in functionally graded circular hollow cylinder with finite length subjected to axisymmetric pressure loadings on inner and outer surfaces are presented in this paper. The cylinder is simply supported at its two ends. Young's modulus of the material is assumed to vary continuously in radial direction of the cylinder. Moreover, numerical results of stresses in functionally graded circular hollow cylinder are appeared.

Determination of mechanical properties of FFF 3D printed material by assessing void volume fraction, cooling rate and residual thermal stresses

2019 ◽  
Vol 25 (10) ◽  
pp. 1661-1683 ◽  
Author(s):  
Rafael Quelho de Macedo ◽  
Rafael Thiago Luiz Ferreira ◽  
Kuzhichalil Jayachandran
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Young’S Modulus ◽  
Thermal Stresses ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Void Volume Fraction ◽  
Void Volume ◽  
Temperature Fields ◽  
Content Type

Purpose This paper aims to present experimental and numerical analyses of fused filament fabrication (FFF) printed parts and show how mechanical characteristics of printed ABS-MG94 (acrylonitrile butadiene styrene) are influenced by the void volume fraction, cooling rate and residual thermal stresses. Design/methodology/approach Printed specimens were experimentally tested to evaluate the mechanical properties for different printing speeds, and micrographs were taken. A thermo-mechanical finite element model, able to simulate the FFF process, was developed to calculate the temperature fields in time, cooling rate and residual thermal stresses. Finally, the experimental mechanical properties and the microstructure distribution could be explained by the temperature fields in time, cooling rate and residual thermal stresses. Findings Micrographs revealed the increase of void volume fraction with the printing speed. The variations on voids were associated to the temperature fields in time: when the temperatures remained high for longer periods, less voids were generated. The Young's Modulus of the deposited filament varied according to the cooling rate: it decreased when the cooling rate increased. The influence of the residual thermal stresses and void volume fraction on the printed parts failure was also investigated: in the worst scenarios evaluated, the void volume fraction reduced the strength in 9 per cent, while the residual thermal stresses reduced it in 3.8 per cent. Originality/value This work explains how the temperature fields can affect the void volume fraction, Young's Modulus and failure of printed parts. Experimental and numerical results are shown. The presented research can be used to choose printing parameters to achieve desired mechanical properties of FFF printed parts.

Tangguh LNG Project Statistical Young’s Modulus and Thermal Expansion Coefficient Testing of Clad Pipe Specimens

2011 ◽  
Author(s):  
Terry Griffiths ◽  
Isabel Hadley ◽  
Richard Johnson ◽  
Fabio Micari
Keyword(s):  
Thermal Expansion ◽  
Young’S Modulus ◽  
Room Temperature ◽  
Structural Reliability ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Linear Thermal Expansion ◽  
Upheaval Buckling ◽  
Analysis Of Results ◽  
Mean And Variance

Material testing was undertaken on samples taken from clad pipe manufactured by JSW for the Tangguh LNG project. The test programme involved testing Young’s Modulus (E) and Coefficient of Linear Thermal Expansion (α) from room temperature to above 110° on each layer. This paper summarises testing and analysis of results which enabled mean and variance on each material property to be found. Checks were also undertaken for any correlations in properties between clad and parent layers, and between Young’s Modulus and Coefficient of Thermal Expansion. Analysis results are compared to existing industry norms and their implications for the Tangguh project UHB (Upheaval Buckling) SRA (Structural Reliability Analysis) are summarised.

scholarly journals Viscoelasticity in simple indentation-cycle experiments: a computational study

2020 ◽  
Author(s):  
Yu.M. Efremov ◽  
S.L. Kotova ◽  
P.S. Timashev
Keyword(s):  
Young’S Modulus ◽  
Relaxation Function ◽  
Young's Modulus ◽  
Computational Study ◽  
Viscoelastic Behavior ◽  
Elastic Model ◽  
Experimental Conditions ◽  
Relaxation Functions ◽  
Force Curves ◽  
Linear Viscoelastic Theory

Instrumented indentation has become an indispensable tool for quantitative analysis of the mechanical properties of soft polymers and biological samples at different length scales. These types of samples are known for their prominent viscoelastic behavior, and attempts to calculate such properties from the indentation data are constantly made. The simplest indentation experiment presents a cycle of approach (deepening into the sample) and retraction of the indenter, with the output of the force and indentation depth as functions of time and a force versus indentation dependency (force curve). The linear viscoelastic theory based on the elastic-viscoelastic correspondence principle might predict the shape of force curves based on the experimental conditions and underlying relaxation function of the sample. Here, we conducted a computational analysis based on this theory and studied how the force curves were affected by the indenter geometry, type of indentation (triangular or sinusoidal ramp), and the relaxation functions. The relaxation functions of both traditional and fractional viscoelastic models were considered. The curves obtained from the analytical solutions, numerical algorithm and finite element simulations matched each other well. Common trends for the curve-related parameters (apparent Young’s modulus, normalized hysteresis area, and curve exponent) were revealed. Importantly, the apparent Young’s modulus, obtained by fitting the approach curve to the elastic model, demonstrated a direct relation to the relaxation function for all the tested cases. The study will help researchers to verify which model is more appropriate for the sample description without extensive calculations from the basic curve parameters and their dependency on the indentation rate.

scholarly journals Stress Uniformity Analyses on Nonparallel End-Surface Rock Specimen during Loading Process in SHPB Tests

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Pu Yuan ◽  
Qin-yong Ma ◽  
Dong-dong Ma
Keyword(s):  
Young’S Modulus ◽  
Rock Specimen ◽  
Young's Modulus ◽  
Stress Waves ◽  
Elastic Model ◽  
Equilibrium Time ◽  
Stress Equilibrium ◽  
Loading Process ◽  
Pressure Bar ◽  
Stress Uniformity

To investigate the influence of nonparallel end-surface on stress uniformity during loading process in rock SHPB test, SHPB numerical simulations have been carried out by LS-DYNA when end-face nonparallelism is within 0.40% and Young’s modulus ranges from 14 GPa to 42 GPa. Isotropic linear elastic model is applied for elastic steel pressure bar, and HJC constitutive model is chosen for rock specimen. Numerical simulation results indicate that fluctuation effect exists in both reflected stress waves and transmitted stress waves, and it is enhanced with the increase of end-surface nonparallelism. The stress nonuniformity coefficient attenuates in a serrated fluctuation. With the increase of end-surface nonparallelism, the amplitude of transmitted stress wave gradually reduces, while stress nonuniformity coefficient increases. Stress equilibrium time first decreases slightly then increases in a step type. Therefore, nonparallel end-surface leads to two reverse results for stress uniformity during SHPB loading process, extending stress equilibrium time and shortening stress equilibrium time. And the influence on shortening stress equilibrium time is weak, while the influence on extending stress equilibrium time is great. When end-surface nonparallelism is 0.10%, stress equilibrium time achieves its lowest value whatever Young’s modulus is. Hence, end-surface nonparallelism of the rock specimen is suggested to be controlled within 0.10% when conducting SHPB tests.

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