scholarly journals Thermal and Mechanical Properties of Sn-8Zn-3Bi Solder Alloy

2021 ◽  
Vol 31 (5) ◽  
pp. 75-80
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Solder Alloy ◽  
Liquidus Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Copper Substrate ◽  
Strain Curve ◽  
Thermal And Mechanical Properties ◽  
Stress Strain Curve ◽  
Testing Condition

Thermal and mechanical properties of Sn-8Zn-3Bi solder alloy on copper substrate were evaluated via measuring the melting temperature, the coefficient of thermal expansion (CTE), the tensile and shear strength of the solder joint. The measured properties of the alloy were then compared to the properties of the traditional and widely used eutectic Sn-37Pb solder alloy. The results show that the melting (liquidus) temperature of Sn-8Zn-3Bi was 195 °C, the CTE of Sn-8Zn-3Bi was 22.2´10-6 K-1 in the temperature range of 30-130 °C. At the same testing condition, both tensile and shear strength of Sn-8Zn-3Bi joints were higher than those of Sn-37Pb. The stress-strain curve indicated that the Sn-8Zn-3Bi joints were brittle whilst the Sn-37Pb joints were ductile.

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.

scholarly journals Three-dimensional numerical simulation of mechanical properties of soil-tire mixture by discrete element method

2019 ◽  
Vol 92 ◽  
pp. 14011
Author(s):  
Mohsen Asadi ◽  
Ahmad Mahboubi
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Damping Ratio ◽  
Strain Curve ◽  
Young Modulus ◽  
Engineering Properties ◽  
Triaxial Tests ◽  
Sand Particle ◽  
Arithmetic Average ◽  
Harmonic Average

Soil engineering properties can be improved employing different methods. Among them is mixing soil with tire derived additives (TDA). TDAs generally increase some parameters of mixture such as damping ratio, permeability, ductility and also in some cases shear strength. Various properties of TDAs from mechanical properties to their geometry can affect the mixture behavior. In this paper using the YADE platform, simulations of triaxial tests on sand tire mixtures are presented. To take compressibility into consideration, each rubber crumb particle is made of several spheres connected elastically to each other. For sand particle generation the clump technique was employed. Shapes of both sand and rubber particles are inspired from real grains. As properties of sand and rubber are different, especially Young modulus, rubber sand interaction is considered as soft rigid contact. Therefor harmonic average and arithmetic average was used to compute contact Young modulus (and then stiffness). The model was validated by comparison of results of triaxial tests simulation on pure rubber sample with literature ones which both exhibited linear stress-strain curve. Then triaxial tests with different sand to rubber ratio were simulated to see whether harmonic average or arithmetic average gives the best match to literature. The results show shear strength reduces by decreasing of sand to rubber ratio. This is the same as what is reported in literature.

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.

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.

Local and Global Damages of Quasi-Brittle Material in Uniaxial Compression Based on Gradient-Dependent Plasticity

2005 ◽  
Vol 293-294 ◽  
pp. 719-726 ◽  
Author(s):  
X.B. Wang
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Uniaxial Compression ◽  
Strain Curve ◽  
Damage Variable ◽  
Local Damage ◽  
Stress Strain Curve ◽  
Flow Shear ◽  
Three Point Bending ◽  
Measured Stress

Theoretical relations among local and nonlocal damage variables in localized band as well as global damage variable according to the measured stress-strain curve of quasi-brittle material subjected to shear and tensile failures in uniaxial compression and in three-point bending were presented. The nolocal damage variable depends on the local counterpart and its second spatial gradient based on nonlocal theory. Analytical solution for the local damage variable was derived by substitution of the nonlocal damage variable for averaged damage variable in shear band and by using boundary condition as well as by resorting to the assumption that the actual thickness of shear band corresponds to the maximum local damage variable. It is found that local damage variable depends on the internal length parameter, coordinate, flow shear stress, shear strength, shear elastic and softening moduli. Assuming that the shear localization is initiated just at the peak strength, and that afterwards the strain-softening behavior of specimen occurs. The relation among shear strength, uniaxial compressive strength, flow shear and compressive stresses was established. The global damage variable was defined according to the measured stress-strain curve whether the post-peak response is snap-back or snap-through, which depends on the uniaxial compressive strength and flow compressive stress. A relation among local, nonlocal, and global damage variables in uniaxial compression was proposed analytically, and then a relation applicable to three-point bending was directly presented. The latter relation can be simplified for uniaxial tension condition if tensile stress is assumed to be uniform. Two examples were presented to investigate the two- and three-dimensional distributions of local damage variable in shear and tensile localized bands. The present analytical solutions for the distributed damage in shear and tensile localized bands qualitatively agree with the previous numerical predictions.

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.

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.

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.

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.

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