scholarly journals Effect of In Situ Grown BNNTs and Preparation Temperature on Mechanical Behavior of SiC/SiC Minicomposites

2021 ◽  
Author(s):  
Shenwei Xu ◽  
Huilong Pi ◽  
Pengfei Wu ◽  
Yuan Shi ◽  
Haitang Yang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Fracture Strain ◽  
Thermal Structure ◽  
Annealing Process ◽  
Tangent Modulus ◽  
Tensile Fracture ◽  
Preparation Temperature

Abstract In this paper, effect of in situ grown boron nitride nanotubes (BNNTs) and preparation temperature on mechanical behavior of PIP (Precursor Infiltration and Pyrolysis) SiC/SiC minicomposites under monotonic and compliance tensile is investigated. In situ BNNTs are grown on the surface of SiC fibers using ball milling – annealing process. Composite elastic modulus, tensile strength, fracture strain, tangent modulus, and loading/unloading inverse tangent modulus (ITM) are obtained and adopted to characterize the mechanical properties of the composites. Microstructures of in situ grown BNNTs and tensile fracture surfaces are observed under scanning electronic microscopic (SEM). For SiC/SiC minicomposites with BNNTs, the elastic modulus, tensile strength, and fracture strain are all lower than those of SiC/SiC minicomposites without BNNTs, mainly due to high preparation temperature and the oxidation of the PyC interphase during the annealing process. Tensile stress-strain curves of SiC/SiC minicomposites with and without BNNTs are predicted using the developed micromechanical constitutive model. The predicted results agreed with experimental data. This work will provide guidance for predicting the service life of SiCf/SiC composite materials and may enable these materials to become a backbone for thermal structure systems in aerospace applications.

Test Methods for Mechanical Properties of Structural Adhesives

2010 ◽  
Vol 97-101 ◽  
pp. 814-817 ◽  
Author(s):  
Jun Deng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Elastic Modulus ◽  
Butt Joint ◽  
Test Methods ◽  
Joint Specimen ◽  
Lap Shear ◽  
Better Than

One of the greatest drawbacks to predicting the behaviour of bonded joints has been the lack of reliable data on the mechanical properties of adhesives. In this study, methods for determining mechanical properties of structural adhesive were discussed. The Young’s modulus, Poisson’s ratio and tensile strength of the adhesive were tested by dogbone specimens (bulk form) and butt joint specimens (in situ form). The shear modulus and shear strength were test by V-notched specimens (bulk form) and thick adherend lap-shear (TALS) joint specimens (in situ form). The test results show that the elastic modulus provided by the manufacturer is too low, the dogbone specimen is better than the butt joint specimen to test the tensile strength and elastic modulus and the TALS joint specimen is better than the V-notched specimen to test the shear strength.

In-Situ Estimates of the Tensile Strength of Snow Utilizing Large Sample Sizes

1979 ◽  
Vol 22 (87) ◽  
pp. 321-329 ◽  
Author(s):  
David M. McClung
Keyword(s):  
Tensile Strength ◽  
Loading Rate ◽  
New Method ◽  
Tensile Fracture ◽  
Sample Sizes ◽  
Experimental Procedure ◽  
Large Sample ◽  
Sample Density ◽  
Average Sample

AbstractExperimental procedure and measured estimates of the tensile strength of snow are given by a new method utilizing large sample sizes of naturally deposited snow. Data are presented as a function of average sample density, temperature, loading rate, and snow type. The results show less scatter in the data than previous in-situ estimates and lower mean strength values as a function of density. The relevance of the data to tensile fracture as observed in slab avalanche release is discussed.

The Texture Evolutions of Mg Alloy, AZ31, under Uni-Axial Loading

2005 ◽  
Vol 495-497 ◽  
pp. 1585-1590 ◽  
Author(s):  
Sang Bong Yi ◽  
Heinz Günter Brokmeier ◽  
R. Bolmaro ◽  
Karl Ulrich Kainer ◽  
Jens Homeyer
Keyword(s):  
Tensile Strength ◽  
Mechanical Behavior ◽  
Loading Condition ◽  
Extrusion Direction ◽  
Axial Loading ◽  
X Rays ◽  
The Common ◽  
Initial Texture ◽  
Strain Hardening Rate

The texture influence on the mechanical behavior during uniaxial tension was studied in AZ31 (Mg – 3 Al – 1 Zn in wt.%), one of the common wrought Mg alloys. Since three tensile samples were cut in 0°, 45°, 90° to the extrusion direction, the initial bar texture influences on the mechanical behavior differently. In-situ texture measurements were carried out using hard X-rays under loading condition. According to the initial texture loading results in a variation of the mechanical behavior (yield strength, ultimate tensile strength and strain hardening rate) and in different final textures. The different texture development in each sample relates directly to the activation of different deformation systems, which is strongly influenced by the initial texture

scholarly journals STUDY ON TENSILE MECHANICAL PROPERTY AND MICROSTRUCTURE OF FRUIT AND VEGETABLE PEELS

2019 ◽  
Vol 59 (3) ◽  
pp. 227-236 ◽  
Author(s):  
Juxia Wang ◽  
Decong Zheng ◽  
Qingliang Cui ◽  
Shuanghua Xu ◽  
Bingyao Jiang
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Fruits And Vegetables ◽  
Fracture Strain ◽  
Testing Machine ◽  
Strain Curve ◽  
Mechanical Equipment ◽  
Fruit And Vegetable ◽  
Stress Strain ◽  
Mean Values

Fruit and vegetable peels exert a protective effect on fruits as constituent parts of the outermost tissue and their properties are of great importance to reducing fruit and vegetable mechanical injury. Four kinds of fruit and vegetable peels such as Nagafu apple, Crisp pear, Tainong mango and long eggplant were chosen to perform longitudinal and transverse tests of tensile property by means of electronic universal testing machine. Stress-strain curve, tensile strength, elastic modulus and fracture strain of peels were obtained; and the microstructures of four kinds of peels were scanned using an electron microscope (SEM). The results indicated that cubic polynomials proved superior for quantifying the stress-strain non-linear relationship of peels and the fitting error of tensile strength is less than 10 parts per thousand. Tensile strength, elastic modulus and fracture strain of peels were different in the case of different fruits and vegetables cultivated and different parts of the same peel; fruit and vegetable peels belong to anisotropic heterogeneous materials and have certain strength. The mean values of tensile strength and fracture strain of the long eggplant peel are the biggest in four kinds of peels and that of elastic modulus of Nagafu apple peel is the largest; long eggplant and Nagafu apple peels had better resistance to damage sensibility than Crisp pear peel. The bearing capacity of the peels depends on the number, width and distribution of microcracks on the surface, and the shape of the epidermal cells and fruit dot on peels; the number of microcracks is bigger and the width of microcracks is wider, the tensile strength is smaller and the elastic modulus of peel is bigger with the slippage increase of epidermis cells. This study provides basic technical parameters for mechanical equipment design for fruit and vegetable during harvesting, processing, packaging, storing and transporting and builds the correlations between macro-mechanics properties and microstructures of fruit and vegetable peels.

In-Situ Estimates of the Tensile Strength of Snow Utilizing Large Sample Sizes

1979 ◽  
Vol 22 (87) ◽  
pp. 321-329 ◽  
Author(s):  
David M. McClung
Keyword(s):  
Tensile Strength ◽  
Loading Rate ◽  
New Method ◽  
Tensile Fracture ◽  
Sample Sizes ◽  
Experimental Procedure ◽  
Large Sample ◽  
Sample Density ◽  
Average Sample

AbstractExperimental procedure and measured estimates of the tensile strength of snow are given by a new method utilizing large sample sizes of naturally deposited snow. Data are presented as a function of average sample density, temperature, loading rate, and snow type. The results show less scatter in the data than previousin-situestimates and lower mean strength values as a function of density. The relevance of the data to tensile fracture as observed in slab avalanche release is discussed.

scholarly journals Mechanical Behavior of Recycled Fine Aggregate Concrete with High Slump Property in Normal- and High-Strength

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Minkwan Ju ◽  
Kyoungsoo Park ◽  
Won-Jun Park
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Mechanical Behavior ◽  
High Strength ◽  
Strength Development ◽  
Fine Aggregate ◽  
Structural Concrete ◽  
Aggregate Concrete ◽  
Model Code

AbstractThis study investigated the mechanical behavior of normal strength (NS) and high strength (HS) concrete containing recycled fine aggregates (RFAs). A high slump mixing design was employed, which may be potentially used as filled structural concrete. The compressive strength, tensile strength, and elastic modulus were measured according to the RFA replacement ratio and curing time. In addition, the shrinkage strain was measured in a temperature and humidity chamber over 260 days. The compressive strength and elastic modulus of RFA concrete were approximately 70–90% of those of virgin concrete. The decreases in the compressive strength and elastic modulus for NS concrete were larger than those for HS concrete. This could be explained by the difference in failure mechanism between NS and HS concrete. The average ratio of the compressive strength at 190 days to that at 28 days was 1.15–1.3, and the ratio of the tensile strength at 190 days to that at 28 days was 1.15–1.25. These demonstrate good strength development. The ratios between the elastic modulus and compressive strength for RFA concrete were dissimilar to those for virgin concrete but similar to those for recycled coarse aggregate concrete. ACI 318-14 (Building code requirements for structural concrete and commentary, 2014) and Model Code (Fib model code for concrete structures, 2010) overestimated the elastic modulus of RFA concrete. Therefore, this study suggested an empirical expression to approximate the elastic modulus of RFA concrete. The increase in shrinkage owing to the use of RFA was at most 5–6% of the ultimate compressive strain of concrete.

Tensile Properties of 15wt. %TiB2/7055 Composite Fabricated by In Situ Method

2013 ◽  
Vol 842 ◽  
pp. 165-169 ◽  
Author(s):  
Dong Chen ◽  
Cong Zou ◽  
Yi Jie Zhang ◽  
Nai Heng Ma ◽  
Hao Wei Wang
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Matrix Alloy ◽  
In Situ Method ◽  
The Matrix ◽  
7055 Aluminum Alloy

7055 aluminum alloy reinforced with 15wt. % TiB2 particulates was synthesized by in situ method, the microstructure and tensile properties were investigated. There are a few particulate clusters in the matrix. The elastic modulus and hardness of the composite are higher than that of the matrix alloy, but the yield strength and ultimate tensile strength decrease. The decrease of strength is attributed to the presence of TiB2 particulate cluster and residual reaction slag.

scholarly journals Investigating Tensile Behavior of Sustainable Basalt–Carbon, Basalt–Steel, and Basalt–Steel-Wire Hybrid Composite Bars

2021 ◽  
Vol 13 (19) ◽  
pp. 10735
Author(s):  
Mohammadamin Mirdarsoltany ◽  
Alireza Rahai ◽  
Farzad Hatami ◽  
Reza Homayoonmehr ◽  
Farid Abed
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Modulus Of Elasticity ◽  
Hybrid Composite ◽  
Glass Fibers ◽  
Steel Wire ◽  
Composite Fibers ◽  
Steel Wires ◽  
Steel Bars

One of the main disadvantages of steel bars is rebar corrosion, especially when they are exposed to aggressive environmental conditions such as marine environments. One of the suggested ways to solve this problem is to use composite bars. However, the use of these bars is ambiguous due to some weaknesses, such as low modulus of elasticity and linear behavior in the tensile tests. In this research, the effect of the hybridization process on mechanical behavior, including tensile strength, elastic modulus, and energy absorbed of composite bars, was evaluated. In addition, using basalt fibers because of their appropriate mechanical behavior, such as elastic modulus, tensile strength, durability, and high-temperature resistance, compared to glass fibers, as the main fibers in all types of composite hybrid bars, was investigated. A total of 12 hybrid composite bars were made in four different groups. Basalt and carbon T300 composite fibers, steel bars with a diameter of 6 mm, and steel wires with a diameter of 1.5 mm were used to fabricate hybrid composite bars, and vinyl ester 901 was used as the resin. The results show that, depending on composite fibers used for fabrication of hybrid composite bars, the modulus of elasticity and the tensile strength increased compared to glass-fiber-reinforced-polymer (GFRP) bars by 83% to 120% and 6% to 26%, respectively. Moreover, hybrid composite bars with basalt and steel wires witnessed higher absorbed energy compared to other types of hybrid composite bars.

Effect of Volume Fraction of Reinforcement on the Microstructure and Mechanical Properties of In Situ (TiB+TiC)/Ti Composite

2011 ◽  
Vol 335-336 ◽  
pp. 137-141 ◽  
Author(s):  
Yuong Chen ◽  
Chang Jiang Zhang ◽  
Fan Tao Kong ◽  
Hong Zhi Niu ◽  
Fang Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Room Temperature ◽  
Volume Fraction ◽  
Microstructural Analysis ◽  
Matrix Composites ◽  
Alloy Matrix

In the present study, Ti-6Al-2.5Sn-4Zr-0.7Mo-0.3Si-0.3Y alloy matrix composites reinforced with TiB and TiC were fabricated by combustion-assisted cast utilizing the reaction between titanium and B4C, graphite. The microstructure, room temperature mechanical properties were presented and discussed. Microstructural analysis of the composites revealed that the prior β grain size as well as the thickness of α colony significantly refined with increasing of volume fraction. At room temperature (RT), tensile strength and elastic modulus increase significantly, while the ductility drops gradually possibly because of the cracking of TiB whiskers and TiC particles.

scholarly journals Monotonic and Cyclic Loading/Unloading Tensile Behavior of 3D Needle-Punched C/SiC Ceramic-Matrix Composites

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 57
Author(s):  
Yufeng Liu ◽  
Longbiao Li ◽  
Zhongwei Zhang ◽  
Xiang Xiong
Keyword(s):  
Tensile Strength ◽  
Cyclic Loading ◽  
Residual Strain ◽  
Fracture Strain ◽  
Hysteresis Loops ◽  
Tensile Behavior ◽  
Tangent Modulus ◽  
Peak Strain ◽  
Fiber Volume ◽  
Initial Tangent Modulus

In this paper, monotonic and cyclic loading/unloading tensile behavior of four different 3D needle-punched C/SiC composites are investigated. Under tensile loading, multiple micro parameters of tensile tangent modulus, tensile strength, and fracture strain are used to characterize tensile damage and fracture behavior. Under cyclic loading/unloading, multiple damage micro parameters of unloading residual strain, tensile peak strain, hysteresis loops width, hysteresis loops area, unloading and reloading inverse tangent modulus (ITM) are used to describe the tensile damage evolution. After tensile fracture, fracture surfaces were observed under a scanning electron microscope (SEM). Damage of matrix cracking, interface debonding, fibers fracture and pullout in different plies is observed. Relationships between composite tensile mechanical behavior, damage parameters, and micro damage mechanisms are established. When the fiber volume fraction along the loading direction increases, the composite initial tangent modulus, tensile strength and fracture strain increase, and the unloading residual strain, peak strain, hysteresis width and hysteresis area decrease. For Types 1–4 3D needle-punched C/SiC composite, the fiber volume lies in the range of 25.6–32.8%, the composite initial tangent modulus was in the range of 161.4–220.4 GPa, the composite tensile strength was in the range of 64.4–112.3 MPa, and the composite fracture strain was in the range of 0.16–0.25%.

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