Effect of Temperature Gradients on the Propagation of Elastoplastic Waves

1968 ◽  
Vol 35 (3) ◽  
pp. 441-448 ◽  
Author(s):  
P. H. Francis ◽  
U. S. Lindholm
Keyword(s):  
Mechanical Properties ◽  
Method Of Characteristics ◽  
Wave Attenuation ◽  
Strain Curve ◽  
Temperature Gradients ◽  
Effect Of Temperature ◽  
Plastic Wave ◽  
Temperature Dependent ◽  
Stress Strain Curve ◽  
Elastoplastic Wave

In this paper, the writers consider the problem of the propagation of an extensional elastoplastic wave through a long thin bar heated at the end to produce a continuously decreasing temperature profile. The temperature distribution is approximated as an exponential function, and the stress-strain curve is considered to be bilinear with temperature-dependent mechanical properties. The problem is formulated and solved numerically by the method of characteristics. Several graphical results are provided, and the effects of the temperature gradient and the mechanical properties are discussed in terms of plastic wave attenuation.

Numerical Simulation of the Effect of Temperature on the Failure Strength of Rock

2013 ◽  
Vol 690-693 ◽  
pp. 1737-1740
Author(s):  
Lin Bu ◽  
Tao Xu ◽  
Yun Jie Zhang
Keyword(s):  
Mechanical Properties ◽  
Rock Fracture ◽  
Strain Curve ◽  
Peak Stress ◽  
Effect Of Temperature ◽  
Peak Strain ◽  
Failure Strength ◽  
Stress Strain Curve ◽  
Physical Tests ◽  
Compression Condition

The mechanical properties of granite experiencing high temperatures under uniaxial compression condition were simulated in this paper. Numerically simulated stress-strain curve, peak stress, peak strain and the tangent elastic modulus were compared with the corresponding physical tests. Simulated results agree well with physical tests results, it is shown that Abaqus is suitable for the analysis of the temperature effect on rock fracture.

The role of shear deformation in pure tungsten: Mechanical properties and micro-mechanism

2021 ◽  
pp. 2150142
Author(s):  
Ping Li ◽  
Juan-Juan Shu ◽  
Lu-Sheng Wang ◽  
Miao Meng ◽  
Ke-Min Xue
Keyword(s):  
Mechanical Properties ◽  
Shear Deformation ◽  
Strain Curve ◽  
Shear Angle ◽  
Pure Tungsten ◽  
Stress Strain Curve ◽  
Additional Increase ◽  
Dislocation Strengthening ◽  
Band Deformation

The effects of shear deformation at 1173 K on the mechanical properties and deformation mechanism of pure tungsten are investigated by molecular dynamics (MD). The results show that the shear deformation of pure tungsten is dominated by dislocation multiplication and slip band deformation. The shear angle has a significant effect on the mechanical properties of pure tungsten. The yield strength is 4.21 Gpa at a shear angle of 11[Formula: see text], and it increases significantly to 11.84 Gpa while the shear angle increasing to 27[Formula: see text]. In the plastic deformation stage, the stress–strain curve shows obvious oscillation due to the interaction of dislocations in the single-crystal tungsten and the effect of strain strengthening. In addition, the evolution of dislocation and twining in the compression system against shear angle indicates the variation of deformation behavior. When the shear angle is 11[Formula: see text], the lengths of dislocation 1/2[Formula: see text] and [Formula: see text] increase to a peak rapidly, which illustrates dislocation strengthening. However, when the shear angle is more than 11[Formula: see text], the decrease of dislocation length and the appearance of twins along [Formula: see text] direction demonstrate the twining accompanied with dislocation tangling, resulting in the additional increase of strength.

Mechanical properties of UN-5100 envelope material for stratospheric airship

2020 ◽  
pp. 1-17
Author(s):  
W.-c. Xie ◽  
X.-l. Wang ◽  
D.-p. Duan ◽  
J.-w. Tang ◽  
Y. Wei
Keyword(s):  
Mechanical Properties ◽  
Significant Role ◽  
Strain Curve ◽  
Image Correlation ◽  
Membrane Structures ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Biaxial Tensile ◽  
Envelope Material ◽  
Biaxial Tensile Testing

ABSTRACT Stratospheric airships are promising aircraft, usually designed as a non-rigid airship. As an essential part of the non-rigid airship, the envelope plays a significant role in maintaining its shape and bearing the external force load. Generally, the envelope material of a flexible airship consists of plain-weave fabric, composed of warp and weft fibre yarn. At present, biaxial tensile experiments are the primary method used to study the stress–strain characteristics of such flexible airship materials. In this work, biaxial tensile testing of UN-5100 material was carried out. The strain on the material under unusual stress and the stress ratio were obtained using Digital Image Correlation (DIC) technology. Also, the stress–strain curve was corrected by polynomial fitting. The slope of the stress–strain curve at different points, the Membrane Structures Association of Japan (MSAJ) standard and the Radial Basis Function (RBF) model were compared to identify the stress–strain characteristics of the materials. Some conclusions on the mechanical properties of the flexible airship material can be drawn and will play a significant role in the design of such envelopes.

Effect of temperature on properties of aluminum/single-walled carbon nanotube nanocomposite by molecular dynamics simulation

2019 ◽  
Vol 234 (2) ◽  
pp. 635-642 ◽  
Author(s):  
Mohsen Motamedi ◽  
AH Naghdi ◽  
SK Jalali
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Molecular Dynamics Simulation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Curve ◽  
Dynamics Simulation ◽  
Effect Of Temperature ◽  
Metal Composite

Composite materials have become popular because of high mechanical properties and lightweight. Aluminum/carbon nanotube is one of the most important metal composite. In this research, mechanical properties of aluminum/carbon nanotube composite were obtained using molecular dynamics simulation. Then, effect of temperature on stress–strain curve of composite was studied. The results showed by increasing temperature, the Young’s modulus of composite was decreased. More specifically increasing the temperature from 150 K to 620 K, decrease the Young’s modulus to 11.7%. The ultimate stress of composite also decreased by increasing the temperature. A continuum model of composite was presented using finite element method. The results showed the role of carbon nanotube on strengthening of composite.

Compressive Plasticity of Zr-Based Bulk Metallic Glass at Low Temperature

2012 ◽  
Vol 443-444 ◽  
pp. 583-586
Author(s):  
Ya Juan Sun ◽  
Ri Ga Wu ◽  
Hong Jing Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Low Temperatures ◽  
Room Temperature ◽  
Shear Bands ◽  
Strain Curve ◽  
Testing Temperature ◽  
Stress Strain Curve

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.

scholarly journals Experimental Analysis of Tensile Mechanical Properties of Sprayed FRP

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Zhao Yang ◽  
Kun Wu
Keyword(s):  
Mechanical Properties ◽  
Fiber Length ◽  
Fiber Type ◽  
Volume Ratio ◽  
Strain Curve ◽  
Uniaxial Tensile ◽  
Stress Strain Curve ◽  
Fiber Volume ◽  
Tensile Performance ◽  
Type Fiber

To study the tensile mechanical properties of sprayed FRP, 13 groups of specimens were tested through uniaxial tensile experiments, being analyzed about stress-strain curve, tensile strength, elastic modulus, breaking elongation, and other mechanical properties. Influencing factors on tensile mechanical properties of sprayed FRP such as fiber type, resin type, fiber volume ratio, fiber length, and composite thickness were studied in the paper too. The results show that both fiber type and resin type have an obvious influence on tensile mechanical properties of sprayed FRP. There will be a specific fiber volume ratio for sprayed FRP to obtain the best tensile mechanical property. The increase of fiber length can lead to better tensile performance, while that of composite thickness results in property degradation. The study can provide reference to popularization and application of sprayed FRP material used in structure reinforcement.

Experimental Research on the Stress - Strain Curve of Regional Confined Concrete under Single Axial Press

2014 ◽  
Vol 584-586 ◽  
pp. 1289-1292
Author(s):  
Guo Liang Zhu
Keyword(s):  
Mechanical Properties ◽  
Theoretical Analysis ◽  
Constitutive Model ◽  
Theoretical Basis ◽  
Strain Curve ◽  
Confined Concrete ◽  
Constitutive Relationship ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Relationship Of

Regional confined concrete is base on confined concrete. It is the theory and application of a new attempt and development on confined concrete. To apply it to the actual project, we need to research mechanical properties and establish constitutive relationship of regional confined concrete. According to the research, we had carried on a series of tests, founded the stress-strain constitutive model of regional confined concrete under single axial press. The accuracy of theoretical analysis were more fully verified , and a theoretical basis for the application was provided.

scholarly journals Hybrid-modelling of Mechanical Properties and Thermo-mechanical Behaviour of Chopped Strand Mat Reinforced Thermoset Composites

2020 ◽  
pp. 1-14
Author(s):  
Cornelius Ogbodo Anayo Agbo
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behaviour ◽  
Strain Curve ◽  
Fibre Volume ◽  
Secant Modulus ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Hybrid Modelling ◽  
Thermoset Composites ◽  
Chopped Strand Mat

The concern of this paper is to develop simple workshop application models for predicting the mechanical properties and the evaluation of the thermo-mechanical behaviour of chopped strand fibre-mat reinforced thermoset composites. A hybrid of empirical and strength of materials approach was used at macro- and micro-mechanics levels to model the random fibres which were treated as simple bars within the mat preform and the resulting composite material. The model was validated experimentally by testing wet lay-up produced samples with varying fibre volume fractions and they were found to agree well. The toughness modulus of the composite was also modeled using the secant modulus obtained from the sample’s stress – strain curves of uniform material composites produced at different temperature histories. The toughness modulus determined using the new model was compared with that obtained using the area under the same stress – strain curve computed by Simpson’s rule and the results agreed very well.

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