Papers by Keyword: Tension Test

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Authors: Akbar Afaghi Khatibi, Bohayra Mortazavi
Abstract: Developing new techniques for the prediction of materials behaviors in nano-scales has been an attractive and challenging area for many researches. Molecular Dynamics (MD) is the popular method that is usually used to simulate the behavior of nano-scale material. Considering high computational costs of MD, however, has made this technique inapplicable as well as inflexible in various situations. To overcome these difficulties, alternative procedures are thought. Considering its capabilities, Finite Element Analysis (FEA) seems to be the most appropriate substitute for MD simulations in most cases. But since the material properties in nano, micro, and macro scales are different, therefore to use FEA methods in nano-scale modeling one must use material properties appropriate to that scale. To this end, a previously developed Hybrid Molecular Dynamics-Finite Element (HMDFE) approach was used to investigate the nanoindentation behavior of single crystal silicon with Berkovich indenter. In this study, a FEA model was developed based on the material properties extracted from molecular dynamics simulation of uniaxial tension test on single crystal Silicon. Eventually, by comparison of FEA results with experimental data, the validity of this new technique for the prediction of nanoindentation behavior of Silicon was concluded.
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Authors: Juan Daniel Muñoz-Andrade, A. Mendoza-Allende, Gabriel Torres-Villaseñor, J.A. Montemayor-Aldrete
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Authors: Nilson Tadeu Mascia, Raul Martini Mayer, Reinaldo Washington Moraes
Abstract: Natural fibres have recently raised attention for presenting adequate mechanical characteristics for the reinforcement of wood structural elements. The use of both natural fibres, in laminated beams and wood from reforestation, is in accordance with the current economic interest and sustainable appeal. This paper focuses on the analysis the viability of sisal fibre use, in wood laminated structures as a reinforcing material, taking three methods into consideration: Stress functions, Classical lamination theory and Transformed section method. The laminated beams were reinforced by sisal strips with a thickness of 2 mm and constituted by the species of wood: Pinus (Pinus sp). Each lamina has the following dimensions: width of 5 cm, height of 10 cm and length of 150 cm. It was noted that the differences between the results from the classical lamination theory and transformed section method were, in an average of 14 % and 16 % for normal and shear stresses respectively. The difference of 12 % for displacements is a normal result taking into account that the span used is considered high for this wood species. In relation to the stress function method, the differences are minimal, around less than 1% for all analyses. It was also noted that the beam with reinforcement presented a decrease of the values of normal and shear stresses and displacements in relation a beam without reinforcing fibres. This decrease was of the order of 8% for the normal and 5% for the shear stresses and 12 % for the displacements In general, the strengthening of wood laminated beams with sisal fibres is more effective for structures that are used only in wood structural elements, in which the elastic modulus is at least equal to these fibres.
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Authors: Dae Young Kim, Woo Jong Kang, Haeng Muk Cho, Seong S. Cheon
Abstract: In the present study, the strength characteristics of weld zone in the extruded Al6082-T6 has been investigated both by experiment and finite element analysis. The measured heat affected zone was modeled by the combination of deposited metal and a base metal with randomisation. Results from the randomised finite element analysis were compared with tensile test data depending upon the fracture behavior and strength characteristics of weld zone. Three cases of the randomised macro mixing of two materials in HAZ with three types of mixing ratios. Among them, the case 3, which contains the smallest amount of the portion of the base material, showed good agreement with experiment within the allowable error of 12%.
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Authors: Kun Qi Wang, Chen Cong Meng, Ping Li, Jing Qi Fan
Abstract: This design is a basic method for testing spring fan wheel assembly and steel cable tension control system. PLC is used as logic control core. Stepping motor and magnetic powder braker is used as an executive element. The constant tension control of the running process of the system is completed. The fuzzy control process of PID system includes two parts of tension loading and damping loading. The method of modular software is used to make the program structure clear.
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Authors: Xiao Jiu Feng, Li Fu Liang
Abstract: By conducting simple tension and torsion tests to material, constitutive equations of one dimension are obtained. Plastic theories of continuum mechanics are used for analyzing deformation behavior of the material after yielding. Here, material is presumed to have isotropic hardening characteristic. By using Mises loading function and the associative flow rule, the derivations are made to extend the constitutive equations of one dimension in the simple tension and torsion tests to that of multi-dimension and obtain the plastic constitutive equations of the material in complex stress state , respectively.
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Authors: W. R. Tyson, G. Shen, J. A. Gianetto, D.Y. Park
Abstract: CANMET-MTL has developed a low-constraint test designed to reduce unnecessary conservatism in the measurement of toughness for use in the assessment of flaws in pipeline girth welds. The design is based on tension loading using fixed (clamped) grips of a single-edge-notched BxB SE(T) specimen, side-grooved to promote plane-strain conditions. Equations have been developed to derive J-integral, CTOD and crack growth from measurement of load and crack-mouth opening displacement. Loading conditions (essentially distance between the grips) have been chosen to reproduce the crack-tip constraint of a circumferential surface flaw in a pipe in service under tensile or bending loads. In this paper, the development of the test and the principal findings from its use will be described.
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Authors: Midori Yamaya, Masatoshi Futakawa, Hidefumi Date
Abstract: The mechanical properties of palladium (Pd) wire absorbed hydrogen were evaluated by the quasi-static tension test and indentation test. The electrolytic method was used for hydrogen absorption. Pd wire with a diameter of 1mm was used. The electrolyte was a sulfuric acid solution and the current density used in the electrolytic method was 200mAcm-2. The hydrogen absorption ratio defined by the molecular ratio (H/Pd) of hydrogen and palladium was controlled by the absorption time. The gauge length for the tension test was 20mm. The ultimate tensile strength increased with the increase of the absorption ratio. On the other hand, the increase of the ratio decreased the strain hardening parameter and fracture strain. A model considering the specimen absorbed hydrogen and a composite material constructed in a concentric configuration was suggested to estimate the hydrogen absorption area and mechanical properties. The indentation test was conducted to clarify the evolution of the embrittlement due to the hydrogen absorption microscopically and determine the absorption area precisely. Vickers hardness clearly increased with the increase of the hydrogen absorption ratio. The hardness distribution was measured to detect the boundary of the absorption and non-absorption area using a Berkovich indenter that is smaller than a Vickers indenter. The hardness boundary of the absorption and non-absorption of the specimen with the hydrogen absorption ratio of 22 percent was observed experimentally at the position around 100-150μm from the outside of the specimen. The position of the boundary estimated using the model was 85μm from the outside of the specimen. When the stress-strain curves of the specimen with the unknown hydrogen absorption ratio were measured, the hydrogen absorption ratio could be estimated using the proposed model.
2713
Authors: Yin Huan Yang, Lin Zhi Wu, Ying Guo, Zhen Gong Zhou
Abstract: Tension tests on T700/EXOPY unidirectional laminates single-lap joints of spew fillets at overlap ends under uniaxial tensile loading are performed in the presented paper. Two different types of joints are designed and analyzed in order to study effect of spew fillets and no spew fillets at overlap ends on strength and failure mode of single-lap adhesive joints. According to the results, failure mode of two joints are characterized and analyzed. Shear stress—strain curves are analyzed and compared. At the same time, a finite element simulation is carried out to analyze the peel/shear stress fields inside the joint interface. It is found that joint strength was much affected by spew fillets in overlap ends. Nerveless, joints strength is decreased with the increasing thickness of spew fillets in overlap ends. The computational results are in good agreement with the experimental values.
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