Journal articles: 'Longitudinal Tensile Strength'

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Liu, Bo, and A. Bulent Koc. "Mechanical Properties of Switchgrass and Miscanthus." Transactions of the ASABE 60, no. 3 (2017): 581–90. http://dx.doi.org/10.13031/trans.11925.

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Abstract. The mechanical properties of energy crops in the longitudinal and transverse directions are necessary for modeling and simulation of biomass stems. Modeling of biomass stems would help in analyzing the interactions between processing equipment and biomass material before building physical systems. While some of the mechanical properties of switchgrass and miscanthus stems are available in the literature, these properties are not complete for modeling and simulation of these materials. Therefore, the objective of this research was to determine the mechanical properties of switchgrass and miscanthus stems by using compressive, tensile, and shearing tests in the longitudinal and transverse directions. Tensile, compressive, and shear strengths and modulus of elasticity of switchgrass and miscanthus tended to decrease with decreasing stem diameter in both the longitudinal and transverse directions. Tensile and compressive strengths of the first internode of switchgrass were 178.0 and 27.3 MPa in the longitudinal direction and 0.7 and 4.1 MPa in the transverse direction. Shear strength for the first internode of switchgrass was 2.2 and 21.1 MPa in the longitudinal and transverse directions. Tensile and compressive strengths of the first internode of miscanthus were 373.1 and 56.9 MPa in the longitudinal direction and 1.8 and 6.3 MPa in the transverse direction. Shear strength for the first internode of miscanthus was 94.4 and 8.7 MPa in the transverse and longitudinal directions. The experimental data collected in this research would be useful for the development of simulation models for investigating the interactions between shearing tools and energy crops and in designing harvest and particle reduction equipment. Further research would be useful for determining the effects of moisture content, growth conditions, and maturity stage on the mechanical properties of these crops. Keywords: Biofuel, Compressive strength, Miscanthus, Shear strength, Switchgrass, Tensile strength.

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Vignoli, Lucas L., Marcelo A. Savi, Pedro MCL Pacheco, and Alexander L. Kalamkarov. "Micromechanical analysis of longitudinal and shear strength of composite laminae." Journal of Composite Materials 54, no. 30 (July 2, 2020): 4853–73. http://dx.doi.org/10.1177/0021998320936343.

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The analysis of several micromechanical models for estimating strength of composite laminae is presented. Longitudinal tensile, compressive and in-plane onset shear strengths are analytically estimated and compared with experimental data available in the literature. The tensile longitudinal load predominantly induces rupture of fibers. On the other hand, the compressive strength is highly influenced by fiber misalignment, inducing a wide range of failure mechanisms. The material response to in-plane shear presents a strong nonlinear response. The estimation of longitudinal tensile strength based on the rule of mixture approaches is compared with 27 experimental data. A novel improvement is proposed assuming that in situ strength of fiber is smaller than fiber strength measured individually due to manufacturing induced damage. For the in-plane shear, 6 models are compared with 10 experimental stress-strain curves, including a novel closed-form expression based on the concentric cylinders model. Finally, for the longitudinal compressive strength, 8 micromechanical models, including a novel model to estimate misalignment effect in fiber crushing, are compared with 61 experimental data are analyzed. Results indicate that the minimal average error for the longitudinal tensile strength is 12.4% while for the compressive strength it is 15%. For the shear strength, the closest prediction depends on the strength definition and the proposed damage onset strength presents the best predictions. In general, the newly proposed models present the best estimations compared with the other models.

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Zhao, Rong Jun, Xian Bao Cheng, Wei Wei Shuangguan, Juan Sun, and Ben Hua Fei. "Study on the Longitudinal Tensile Strength of Tracheids of Heat-Treated Wood." Advanced Materials Research 183-185 (January 2011): 1896–900. http://dx.doi.org/10.4028/www.scientific.net/amr.183-185.1896.

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In this paper, the zero-span tensile strengths of tracheids of Chinese fir and Masson pine were investigated, and the effect of the moisture on the tracheid strength was also discussed. Furthermore, the influence of thermal treatment on the zero-span tensile strengths of tracheids were analysed, and research of relationship of zero-span tensile strengths, chemical components and cellulose crystallinity were also conducted. This study tried to explore the inherent mechanism of heat treatment on the cell level.

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Cheng, Xian Bao, Rong Jun Zhao, and Wei Wei Shangguan. "The Research on the Longitudinal Tensile Strength of Tracheids of Brown-Rotted Chinese Fir." Advanced Materials Research 183-185 (January 2011): 2014–18. http://dx.doi.org/10.4028/www.scientific.net/amr.183-185.2014.

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Using Zero-span tensile test technique, measurements of the longitudinal tensile strength of tracheids of brown-rotted Chinese fir were obtained in the present work. The results showed that the longitudinal tensile strength of tracheids reduced with the increase of exposure time. The absolute value of reduced tensile strength was not remarkable because of low degradation efficiency. The FTIR spectroscopy results shows that brown-rot fungus did degraded the cellulose and hemicellulose of Chinese fir, explaining the reduction of tensile strength of tracheids. The intensities of the characteristic aromatic lignin peak at 1512 cm-1 was not increased but decreased, which was very strange, hinting the reason of that is not clearly illustrate by the FTIR spectra only.

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Liu, Ran, De Liang Yin, and Jing Tao Wang. "Effect of Load Direction on Tensile Yield Properties in Mg-3Al-Zn Alloy." Materials Science Forum 682 (March 2011): 145–51. http://dx.doi.org/10.4028/www.scientific.net/msf.682.145.

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Deformation anisotropy of samples from rolled sheet and extruded rod of AZ31 alloy was investigated in the present work. A strong basal plane texture is detected formed during rolling and extrusion, and both rolled and extruded samples exhibit similar mechanical behavior: tensile yield strength is the highest in the specimens parallel to the longitudinal direction, and decrease continuously as the specimen orientation departs from the longitudinal direction. Using texture analysis and optical microscopy it has been found that, the obvious anisotropy can be explained by texture and orientation factor during tension and compression. Basal slip and twinning are restricted when tensile load is applied in the rolling and extrusion direction, which results in high tensile yield strength along the two directions.

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He, En Guang, Li Chen, and Ming Tao Wang. "Study on the Microstructure and Property for T-Joints of Al-Li Alloy Welded by Double Sided Synchronization Fiber Laser." Advanced Materials Research 1095 (March 2015): 859–64. http://dx.doi.org/10.4028/www.scientific.net/amr.1095.859.

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In the experiment, the T-joints of 2060-T8/2099-T83 Aluminum-Lithium by double sided synchronization Fiber laser welding with thickness of 2 mm was studied aimed to know the microstructure, the distributions of micro-hardness, and the tensile strength of the T-joints. The results show that the microstructure is columnar fine grain zone, dendrite zone, and equiaxed crystal zone in turn from the weld fusion line to weld centre; the micro-hardness of the weld is lower than the micro-hardness of base metal, and softening phenomenon appears in the weld; The average circumferential tensile strength of T-joints is 423 MPa at room temperature, which reaches the strength of the base metal 82%, the average longitudinal tensile strength of T-joints is 449 MPa, which reaches the strength of the base metal 87%; The fracture of circumferential tensile samples initiates at the weld toe, and breaks in the weld centre or heat affected zone. The fracture of longitudinal tensile samples initiates at varying cross-section, there are dimples in the fracture surfaces of both circumferential tensile samples and longitudinal tensile samples, and the fracture is ductile.

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Hui, Yuan, Wen Weidong, Wang Yi, Zheng Zhenshan, and Wu Xiong. "A model for longitudinal tensile strength prediction of low braiding angle three-dimensional and four-directional composites." Science and Engineering of Composite Materials 24, no. 3 (May 1, 2017): 447–53. http://dx.doi.org/10.1515/secm-2014-0200.

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AbstractBased on random crack core theory, a model for predicting the longitudinal tensile strength of three-dimensional (3D) four-directional composites with low braiding angle is established. The model carries out accurate theoretical predictions of the longitudinal tensile strength of 3D four-directional braided carbon fiber/resin composites. The average stiffness method is used to calculate elastic constants of an inner single cell of 3D four-directional braided composites. Meanwhile, the corresponding relationship between failure probability of a unidirectional composite fiber bundle and stress level is given based on the random crack core model of the longitudinal tensile strength of a unidirectional composite. Furthermore, strength algorithms of low braiding angle 3D four-directional composites under different damage modes are built on the basis of the Tsai-Hill criterion. In this paper, the dispersion of single fiber strength is also considered in the model, so the size effect of the composite strength can be reflected effectively. At last, the longitudinal tensile strength of 3D four-directional braided carbon fiber/resin composites is predicted and analyzed, and the result shows that this model has high prediction accuracy.

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Vlasov, Valeriy V., and Pavel A. Trutnev. "Strength Characteristics of 3D-Printed PETG-Based Products Optimization." Key Engineering Materials 899 (September 8, 2021): 512–17. http://dx.doi.org/10.4028/www.scientific.net/kem.899.512.

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The paper considers the dependence of the strength properties of 3D-printed parts on FDM printing modes (temperature and speed), as well as the layer arrangement. PETG (polyethylene glycol terephthalate) based filament was chosen as the basis. A 3D printer was used to produce samples with strictly defined orientation of layers — longitudinal and transverse tensile force at different temperature and printing speed. The experiment has established the effect of these two factors on the tensile strength. The strength of the samples printed transversely was higher than the strength of samples printed longitudinally. This indicates a higher interlayer adhesion.

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Zhu, Fei Fei, Zhi Li Zhong, Hua Wu Liu, and Zong Fu Guo. "The Influence of Basalt Fiber Orientation on the Mechanical Property of Composite Board." Advanced Materials Research 194-196 (February 2011): 283–86. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.283.

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The composite board was made of chopped basalt and polypropylene fibers. The manufacturing process included blending, carding, web formation, laminating and compression molding. The tension and bending properties were investigated experimentally. The load - displacement curve of the tensile test revealed that the elastic modulus and maximum vertical load in the longitudinal were far greater than these in the transverse direction; and tensile strengths were far apart in the longitudinal and transverse direction as well. In comparison with the tensile tests, the effect of basalt fiber orientation on the bending modulus and strength were relatively insignificant. In addition, from the micro fibril angle, we also verify that the orientation angle of basalt fiber is an important factor of influence to the mechanical property. In the similar study, the influence hadn’t been seen sufficiently, so this paper provides reference to the actual application of the composite board.

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de Morais, A. B. "Prediction of the longitudinal tensile strength of polymer matrix composites." Composites Science and Technology 66, no. 15 (December 2006): 2990–96. http://dx.doi.org/10.1016/j.compscitech.2006.02.005.

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Tian, Fang, Su Li Xing, and Ying She Luo. "Research on the Influence of the Tension on Dielectric Strength of the Unidirectional Direction Glass Fiber Reinforced Composites." Advanced Materials Research 734-737 (August 2013): 2230–35. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.2230.

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Based on the experimental measurements of materials dielectric strength, this paper is focused on the relationships between dielectric strength of the materials and tensile stress applied on them. The experimental results indicated that the dielectric strengths of the unsaturated polyester resin and the unidirectional glass fiber reinforced composites had an obvious decrease compared with the samples without of it. Furthermore, the dielectric strength decreased with the increase of tensile stress. When tensile stress reached 50% of the material tensile strength, the dielectric strength of the resin decreased 13.36%, and the unidirectional glass fiber reinforced unsaturated polyester composites decreased 19.86% with the tensile stress in the longitudinal direction and 12.06% in the transverse direction. When the experimental samples were broken down by electricity, cracks and pores which would lead to stress concentration were created between the electrodes around the breaking-down point. In a word, it is vital to make a research about the effect of stress on the insulating properties of materials.

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Mad Asasaari, Siti Faizah, King Jye Wong, Mohd Nasir Tamin, and Mahzan Johar. "Moisture absorption effects on the mechanical properties of carbon/epoxy composites." International Journal of Structural Integrity 11, no. 4 (March 29, 2020): 605–14. http://dx.doi.org/10.1108/ijsi-12-2019-0136.

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PurposeThis paper investigates the influence of moisture absorption on the mechanical properties of carbon/epoxy composites.Design/methodology/approachThree types of specimens are prepared, which are for longitudinal, transverse and shear tests. Specimens are immersed in distilled water at 70°C for 1, 3 and 9 months. These correspond to the moisture content of 2.2, 3.8 and 5.3%.FindingsCompared to the values at dry condition, the longitudinal modulus, shear modulus and Poisson's ratio are invariant with the moisture content. However, the transverse modulus, transverse strength and shear strength are sensitive to moisture attack. The maximum degradation is 33%, 76 and 33% for the three properties, respectively. It is also worth to note that the longitudinal tensile strength is stable at 1 and 9 months of immersion. However, at 3-months ageing period, there is only 67% of the longitudinal tensile strength retained.Originality/valueThe experimental results are fitted with a residual property model. Results show comparatively good fit, with a difference within 16% except the longitudinal tensile strength at 9-months immersion. This highlights that the model is not suitable to fit the experimental data with a fluctuated trend.

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Nakada, Masayuki, and Yasushi Miyano. "Temperature dependence of statistical fatigue strengths for unidirectional carbon fiber reinforced plastics under tension loading." Journal of Composite Materials 54, no. 14 (November 7, 2019): 1797–806. http://dx.doi.org/10.1177/0021998319886629.

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The formulation for time- and temperature-dependent statistical static and fatigue strengths for carbon fiber reinforced plastics laminates is newly proposed based on the physically serious role of resin viscoelasticity as the matrix of carbon fiber reinforced plastics. In this study, this formulation is applied to the tensile strength along the longitudinal direction of unidirectional carbon fiber reinforced plastics constituting the most important data for the reliable design of carbon fiber reinforced plastics structures which are exposed to elevated temperatures for a significant period of their operative life. The statistical distribution of the static and fatigue strengths under tension loading along the longitudinal direction of unidirectional carbon fiber reinforced plastics were measured at various temperatures by using resin-impregnated carbon fiber reinforced plastics strands as specimens. The master curves for the fatigue strength as well as the static strength of carbon fiber reinforced plastics strand were constructed based on the time–temperature superposition principle for the matrix resin viscoelasticity. The long-term fatigue strength of carbon fiber reinforced plastics strand can be predicted by using the master curve of fatigue strength.

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Ramakrishna, S., H. Hamada, and H. Naito. "Tensile Behaviour of Pultruded FRP Sandwich Composite Bolted Joints." Advanced Composites Letters 3, no. 3 (May 1994): 096369359400300. http://dx.doi.org/10.1177/096369359400300302.

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In this experimental study, the tensile behaviour of bolted joints of pultruded glass fibre reinforced polyester sandwich composites was investigated. The transverse specimens cut normal to the pultrusion direction failed by net-tension whereas the longitudinal specimens cut parallel to the pultrusion direction failed by a combination of bearing and shear-out modes. The joint strength was dependent on the specimen geometry in the case of transverse specimens whereas it was not in the case of longitudinal specimens.

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Putic, Slavisa, Marina Stamenovic, Jelena Petrovic, Marko Rakin, and Bojan Medjo. "Effect of alkaline solutions on the tensile properties of glass-polyester pipes." Acta Periodica Technologica, no. 42 (2011): 185–95. http://dx.doi.org/10.2298/apt1142185p.

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Construction materials, traditionally used in process equipment, are today successfully replaced by composite materials. Hence, many pipes are made of these materials. The subject of this study was the influence of liquids on the state of stresses and tensile strengths in the longitudinal and circumferential direction of glass-polyester pipes of a definite structure and known fabrication process. These analyses are of great importance for the use of glass-polyester pipes in the chemical industry. The tensile properties (the ultimate tensile strength and the modulus of elasticity) were tested and determined for specimens cut out of the pipes; flat specimens for the tensile properties in the longitudinal direction and ring specimens for the tensile properties in the circumferential direction. First, the tension test was performed on virgin samples (without the influence of any liquid), to obtain knowledge about the original tensile properties of the material composite studied. Subsequently, the specimens were soaked in alkaline solutions: sodium hydroxide (strong alkali) and ammonium hydroxide (weak alkali). These solutions were selected because of their considerable difference in pH values. The specimens and rings were left for 3, 10, 30 and 60 days in each liquid at room temperature. Then, the samples were tested on tension by the standard testing procedure. A comparison of the obtained results was made based on the pH values of the aggressive media in which the examined material had been soaked, as well as based on the original tensile properties and the number of days of treatment. Micromechanical analyses of sample breakage helped in the elucidation of the influence of the liquids on the structure of the composite pipe and enabled models and mechanisms that produced the change of strength to be proposed.

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Huang, Zheng-Ming, Wei-Jing Guo, Hong-Bo Huang, and Chun-Chun Zhang. "Tensile Strength Prediction of Short Fiber Reinforced Composites." Materials 14, no. 11 (May 21, 2021): 2708. http://dx.doi.org/10.3390/ma14112708.

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Essentially, every failure of a short fiber reinforced composite (SFRC) under tension is induced from a matrix failure, the prediction of which is of fundamental importance. This can be achieved only when the homogenized stresses of the matrix are converted into true values in terms of stress concentration factors (SCFs) of the matrix in an SFRC. Such an SCF cannot be determined in the classical way. In this paper, a closed-form formula for the longitudinal tensile SCF in the SFRC is derived from the matrix stresses determined through an elastic approach. The other directional SCFs in an SFRC are the same as those in a continuous fiber composite already available. A bridging model was used to calculate the homogenized stresses explicitly, and a failure prediction of the SFRC with arbitrary fiber aspect ratio and fiber content was made using only the original constituent strength data. Results showed that the volume fraction, the aspect ratio, and the orientation of the fiber all have significant effect on the tensile strength of an SFRC. In a certain range, the tensile strength of an SFRC increases with the increase in fiber aspect ratio and fiber volume content, and the strength of the oriented short fiber is higher than that of the random short fiber arrangement. Good correlations between the predicted and the available measured strengths for a number of SFRCs show the capability of the present method.

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Wijnbergen, Diede Christine, Merel van der Stelt, and Luc Martijn Verhamme. "The effect of annealing on deformation and mechanical strength of tough PLA and its application in 3D printed prosthetic sockets." Rapid Prototyping Journal 27, no. 11 (August 24, 2021): 81–89. http://dx.doi.org/10.1108/rpj-04-2021-0090.

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Purpose Fused filament fabrication (FFF) using tough poly lactic acid (PLA) was determined to be the most suited method to achieve low-cost prosthetic sockets. However, improvement in the material properties is desirable to strengthen these sockets. This study aims to evaluate annealing as a potential method to improve material properties by a heat treatment of the object after 3D printing. Design/methodology/approach Four different annealing methods and a control group were tested according to ISO standard 527–1 and ISO standard 527–2. The four annealing methods included: oven; sand; water; and glycerol annealing. Tests were performed on longitudinal and transversal 3D printed samples. Deformation was determined on 3D printed test rings. Findings Annealing using an oven, sand and water resulted in a significant increase in tensile strength in longitudinally 3D printed tensile test samples. However, the tensile strength was decreased in the transversally 3D printed tensile test samples. The tensile modulus had no significant increase in the longitudinally and transversally printed samples. Sand annealing resulted in the least deformation, with a shrinkage of 2.04% of inner diameter and an increase in height of 1.99% for the horizontally annealed test rings. Research limitations/implications The annealing of prosthetic sockets is not recommended as a decrease in tensile strength in transversally printed tensile test samples was observed. More research is needed towards the strengthening of tough PLA in both print directions. Originality/value This paper fulfils the need for understanding the impact of annealing on 3D printed items intended for daily use, such as a prosthetic socket.

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Zhang, Guo Jun, Yong Bin Jia, and Xi Lin Lu. "The Strain Change Rules of Full-Scale High Strength Concrete Frame Columns with High Axial Compression Rations." Advanced Materials Research 919-921 (April 2014): 288–91. http://dx.doi.org/10.4028/www.scientific.net/amr.919-921.288.

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Based on experimental study of 9 full-scale high-strength concrete(HSC) rectangular frame columns with high axial compression ratios, high-strength longitudinal reinforcements and transverse reinforcements and rectangular interlocking ties, their strain change rules of longitudinal reinforcement, stirrups and concrete were discussed and analyzed. The main results indicate as follows. The maximum tensile strain of longitudinal reinforcement decrease and the tensile strain of concrete increase quickly as the axial compression ratios and the strength grades of concrete are higher; the strains of outer stirrups are all the time greater than those of inner stirrups; the single brace stirrups have the same action with the closed stirrups.

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Chen, AS, J. Smith, RS Bushby, MG Phillips, and VD Scott. "Tensile Property Evaluation of Continuous Fibre MMC." Advanced Composites Letters 3, no. 3 (May 1994): 096369359400300. http://dx.doi.org/10.1177/096369359400300304.

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A tensile test method is described for continuous fibre metal matrix composites and used to evaluate the properties of aluminium alloy reinforced with Altex fibre. The composite, which was manufactured to a high quality using liquid-metal infiltration, was shown to possess high longitudinal modulus and strength and to have a transverse strength comparable with that of unreinforced alloy.

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Ba, Ying, and Shu Sun. "Tensile and fatigue properties of fiber-reinforced metal matrix composites Cf/5056Al." Composites and Advanced Materials 30 (January 1, 2021): 2633366X2092971. http://dx.doi.org/10.1177/2633366x20929712.

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Fiber-reinforced metal matrix composites have mechanical properties highly dependent on directions, possessing high strength and fatigue resistance in fiber longitudinal direction achieved by weak interface bonding. However, the disadvantage of weak interface combination is the reduction of transversal performances. In this article, tensile and fatigue properties of carbon fiber-reinforced 5056 aluminum alloy matrix (Cf/5056Al) composite under the condition of medium-strength interface combination are carried out. The fatigue damage mechanisms of Cf/5056Al composite under tension–tension and tension–compression loads are not the same, but the fatigue life curves are close, which may be the result of the medium-strength interface combination.

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Jen, Ming Hwa, Che Kai Chang, Yi Chun Sung, and Feng Chi Hsu. "Manufacturing and Mechanical Responses of Ti/APC-2 Nanocomposite Cross-Ply and Quasi-Isotropic Laminates at Elevated Temperature." Advanced Materials Research 150-151 (October 2010): 796–99. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.796.

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Both Ti/APC-2 cross-ply and quasi-isotropic nanocomposite laminates were successfully fabricated. Basically, the tensile tests at elevated temperature were conducted to obtain the baseline data of mechanical properties, such as strength and stiffness. The results for both types of laminates of longitudinal stiffness predicted by the rule of mixtures (ROM) were in good agreement with experimental data, whilst, those ultimate strength predicted by ROM were lower than the measured data. Then, the tension-tension (T-T) constant stress amplitude cyclic tests were performed at elevated temperature to receive the S-N curves, fatigue strength and life. It is a surprise that almost no delaminations were observed in tensile and cyclic tests, even at elevated temperature and over a million cycles.

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Hirschmüller, Sebastian, Roman Marte, and Alexander Englberger. "Applicability of finger jointing to circular laminated veneer hollow sections for temporary soil nailing." European Journal of Wood and Wood Products 78, no. 5 (August 6, 2020): 879–89. http://dx.doi.org/10.1007/s00107-020-01577-y.

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Abstract This paper investigates the strength properties of circular laminated veneer lumber hollow sections made of beech wood and loaded in tension. These tubular, hollow wooden poles are intended for an innovative geotechnical approach, which utilizes the high tensile strength of beech wood and its limited durability as soil nails for temporary geotechnical slope stabilisation. Due to the standardized design approaches of soil nail walls that prevent a rigid soil body from sliding by using nails as reinforcement elements, primary tension loads will be aligned to the structural elements. Depending on the height of the soil nail wall, nails with a length up to 10 m may be necessary, demanding for high-performance longitudinal section joints due to the natural length limitations of the wood veneer. This paper discusses the applicability of finger jointing to tubular, laminated beech wood veneer poles and presents the results of large-scale tensile tests. Depending on the joint arrangement, the median tensile strength is reduced by 37–43% compared to the unjointed sections of a similar geometry. Thus, finger jointing has been found to be an efficient method of a longitudinal load-carrying connection in combination with a minimized cross section reduction at the joint. However, due to the low sample size of the tests, further improvements are necessary.

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Černý, Ivo, and Dagmar Mikulová. "Static Tensile Strength and E-Modulus Evaluation of a High-Strength Reinforcing Textile Fabrics." Solid State Phenomena 258 (December 2016): 562–65. http://dx.doi.org/10.4028/www.scientific.net/ssp.258.562.

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An experimental approach developed and used for an evaluation of basic static mechanical properties of textile fabric with predominantly longitudinal orientation of yarns, namely static strength and elastic modulus, is described in the paper. The fabric was made using yarns of a dark colour, but no further details were available. Attempts to test just the fabric were not successful and valid due to problems with gripping. Therefore, thin composite plates made of the fabric as the main constituent were sectioned and longitudinal strips were statically loaded with strain measurement. To evaluate the elastic modulus and strength of the fabric in itself, the following steps were performed: (i) cross section area of the strips was evaluated using optical microscope considering effects of the corrugated specimen surface, (ii) area of resin and pores between the yarns was eliminated using Quick PHOTO Industrial 2.3 software and eventually (iii) total cross section of fibres within the yarns was estimated on the basis of closest arrangement assumption. The results are presented and discussed from the viewpoint of a possible aramid type.

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Hamed, G. R., and N. Rattanasom. "Effect of Crosslink Density on Cut Growth in Black-Filled Natural Rubber Vulcanizates." Rubber Chemistry and Technology 75, no. 5 (November 1, 2002): 935–42. http://dx.doi.org/10.5254/1.3547693.

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Abstract Tensile strengths, σb, of gum and N115-filled natural rubber test pieces, with and without edge pre-cuts, have been determined. At low crosslink density, the regular (uncut) σb of filled and gum vulcanizates is similar. However, at high crosslink density, the gum NR becomes brittle, while the corresponding filled rubber remains strong and resistant to cut growth. It is proposed that the tightly linked gum does not strain-crystallize appreciably during stretching, but that its filled counterpart does. Carbon black appears capable of inducing crystallization in a network that alone remains amorphous during extension. Filled vulcanizates of various crosslink densities have similar normal tensile strengths ( ≈ 30 MPa), but strengths differ, sometimes more than twofold, if a pre-cut is present. Lightly crosslinked specimens containing a small cut have strengths that depend very weakly on cut size, c. Furthermore, these develop long longitudinal cracks from which catastrophic rupture initiates. With larger cuts, strength decreases more rapidly with increasing c, there is less longitudinal crack growth, and rupture initiates near the original cut tip. In contrast, the strength of a highly crosslinked vulcanizate is sensitive to small cuts and test pieces exhibit minimal longitudinal cracking before failure.

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Yufen, Wu, Zhang Weifang, Wang Shuang, and Zhang Boming. "Prediction method of longitudinal tensile strength for unidirectional composites with interphase." Journal of Reinforced Plastics and Composites 32, no. 8 (January 15, 2013): 540–46. http://dx.doi.org/10.1177/0731684412473358.

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Ma, Qiu Rong, Hong Da Chen, Yan Hua Li, and He Li. "The Effect of Pre-Strain and Strain Aging on Properties of X100 Line Pipe." Advanced Materials Research 690-693 (May 2013): 2270–74. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.2270.

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Tensile and impact toughness test on X100 line pipe with different pre-strain at different aging temperature were conducted to study the effect of pre-strain and aging temperature on properties of X100 line pipe. The result shows that yield strength and tensile strength of X100 line pipe would increase significantly with the introduction of pre-strain, while the impact toughness would decrease significantly. Effect of strain aging on tensile properties of X100 line pipe are more significantly. The yield strength, and tensile strength would increase significantly with the introduction of strain aging both transversal and longitudinal direction.

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Hamed, G. R., and M. Y. Huang. "Tensile and Tear Behavior of Anisotropic Double Networks of a Black-Filled Natural Rubber Vulcanizate." Rubber Chemistry and Technology 71, no. 5 (November 1, 1998): 846–60. http://dx.doi.org/10.5254/1.3538513.

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Abstract Double networks of a black-filled natural rubber composition have been prepared by partially curing a sheet, stretching it, and then completing cure. Upon release, a double network retracts to a residual extension ratio, αr. Samples cut perpendicular to the stretch direction have stress—strain responses like the isotropic single network, while parallel samples have enhanced stiffness and tensile strength, and reduced extensibility. Tensile strength is rather weakly dependent on αr. Tear strengths of the double networks, determined using edge-cut strip specimens, exceed that of the single network for low αr. However, when αr is high, double networks have very low tear strengths. Consistent with previous studies, high tear strengths are associated with extensive longitudinal cracking.

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Bachtiar, Erik V., Markus Rüggeberg, and Peter Niemz. "Mechanical behavior of walnut (Juglans regia L.) and cherry (Prunus avium L.) wood in tension and compression in all anatomical directions. Revisiting the tensile/compressive stiffness ratios of wood." Holzforschung 72, no. 1 (December 20, 2017): 71–80. http://dx.doi.org/10.1515/hf-2017-0053.

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AbstractThe mechanical properties of walnut (Juglans regiaL.) and cherry (Prunus aviumL.) woods, as frequent raw materials in cultural heritage objects, have been investigated as a function of the anatomical directions and the moisture content (MC). The strength data are decreasing with increasing MC, whereas the tensile strength in the longitudinal direction is higher by factors of 1.5–2 compared to the compression strength. Moreover, the inequality of tensile and compressive stiffness is discussed, which is a matter of debate since a long time. This so-called bimodular behavior is difficult to describe in a generalized mode due to the high data variability if tension and compression properties are analyzed on different samples. If tensile and compressive stiffness tests are performed on the same samples of walnut and cherry wood, the ratio between these properties is significantly higher than 1.

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Wang, Zhenjun, Siyuan Yang, Zehui Du, Wugui Jiang, Aodi Zhang, Changchun Cai, and Wei Yang. "Micromechanical Modeling of Damage Evolution and Mechanical Behaviors of CF/Al Composites under Transverse and Longitudinal Tensile Loadings." Materials 12, no. 19 (September 26, 2019): 3133. http://dx.doi.org/10.3390/ma12193133.

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This paper investigates the progressive damage and failure behavior of unidirectional graphite fiber-reinforced aluminum composites (CF/Al composites) under transverse and longitudinal tensile loadings. Micromechanical finite element analyses are carried out using different assumptions regarding fiber, matrix alloy, and interface properties. The validity of these numerical analyses is examined by comparing the predicted stress-strain curves with the experimental data measured under transverse and longitudinal tensile loadings. Assuming a perfect interface, the transverse tensile strength is overestimated by more than 180% and the transverse fracture induced by fiber failure is unrealistic based on the experimental observations. In fact, the simulation and experiment results indicate that the interface debonding arising from the matrix alloy failure dominates the transverse fracture, and the influence of matrix alloy properties on the mechanical behavior is inconspicuous. In the case of longitudinal tensile testing, however, the characteristic of interface bonding has no significant effect on the macroscopic mechanical response due to the low in-situ strength of the fibers. It is demonstrated that ultimate longitudinal fracture is mainly controlled by fiber failure mechanisms, which is confirmed by the fracture morphology of the tensile samples.

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WANG, B., R. G. XIE, and J. B. TANG. "Biomechanical Analysis of a Modification of Tang Method of Tendon Repair." Journal of Hand Surgery 28, no. 4 (August 2003): 347–50. http://dx.doi.org/10.1016/s0266-7681(03)00019-6.

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We report a modification of the original Tang technique of tendon repair which uses fewer sutures and has fewer knots on the tendon surface. The modified method consists of six longitudinal and two horizontal strands that form an “M” configuration within the tendon and four dorsal longitudinal strands made with a single looped suture. Thirty-six fresh pig flexor tendons were divided and repaired with either the modified Tang or the Tang method. The tendons were subjected to linear or 90° angular loading in an Instron tensile machine. The gap formation strength and ultimate strength of the modified Tang repair was statistically identical to those of the Tang method under linear tension. Under angular tension, the ultimate strength of the modified Tang method was greater than that of the Tang method.

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Ciganik, Christina, John Speer, Kip Findley, and Walther van Raemdonck. "Effects of Post-Drawing Surface Heat Treatments on the Strength and Torsional Ductility of High Strength Steel Wire." Materials Science Forum 941 (December 2018): 1790–95. http://dx.doi.org/10.4028/www.scientific.net/msf.941.1790.

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Along with high tensile strength, high carbon steel wires must possess sufficient torsional ductility is to avoid longitudinal splitting along the wire axis, known as delamination. Often, wires ductile in the bright (asdrawn) surface condition exhibit delamination failure after undergoing a post-drawing surface treatment such as hot-dip galvanizing. The objectives of this study were to examine the influence of postdrawing heat treatment time and temperature on drawn wire mechanical properties, and to identify possible treatment conditions that suppress delamination. Stelmor cooling or lead patenting prior to drawing were used to develop a pearlitic microstructure. Salt pot heat treatments simulated postdrawing heat treatments; experimental heat treatments were conducted between 325 °C and 475 °C for 20 s or at 450 °C for immersion times between 1 s and 20 s. Tension and torsion tests quantified the changes in mechanical properties due to aging. Lead patented wires experienced greater tensile strength and torsional ductility changes with aging time and temperature when compared to the Stelmor cooled wires. This increased sensitivity was attributed to greater dislocation recovery in the patented wire after drawing.

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Mukhopadhyay, Akash, and Probir Saha. "Mechanical Characterization of Aluminium Alloy 6061 Powder Deposit Made by Friction Stir Based Additive Manufacturing." Key Engineering Materials 846 (June 2020): 110–16. http://dx.doi.org/10.4028/www.scientific.net/kem.846.110.

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Additive Friction Stir (AFS) has the potential for extensive future application in metal based additive manufacturing. Powder based AFS is specifically useful for fabricating functionally graded structures. But, the consolidation of powder inside the hollow tool used in this operation hinders the powder based AFS process. This problem could be resolved by Additive Friction Stir Processing (AFSP) while maintaining the key advantages of AFS. A 3D deposit structure of height 5 mm and width 64 mm was made from Al6061 alloy powder by AFSP. Mechanical properties like ultimate tensile strength, yield strength and micro-hardness of the deposit were evaluated in both longitudinal and transverse directions. The ultimate tensile strength and micro-hardness of the deposit were comparable to Al6061-O and there was a significant increment in tensile yield strength. Also, the isotropic nature of the deposit could be inferred from similar mechanical properties in the longitudinal and transverse direction. Dimple ruptures seen in fractographic analysis gave evidence to the ductile nature of the deposit.

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WANG, B., and J. B. TANG. "Increased Suture Embedment in Tendons: An Effective Method to Improve Repair Strength." Journal of Hand Surgery 27, no. 4 (August 2002): 333–36. http://dx.doi.org/10.1054/jhsb.2002.0773.

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We evaluated the effect of length of suture embedment within tendons on the tensile strength of repaired tendons. Thirty fresh pig flexor tendons were divided into three groups and subjected to repairs with the Halsted tendon sutures in which 1/3, 1/2, and 2/3 of the length of the longitudinal sutures was embedded within the tendons. The repaired tendons were pulled to complete failure by an Instron tensile testing machine. The 2 mm gap-formation force, ultimate strength, stiffness, and energy to failure were greatest when 2/3 of the suture length was embedded within the tendon. The results indicate that suture embedment is an important contributor to the tensile properties of the repair, and that increase in length of suture embedment is an effective way to strengthen tendon repairs.

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Ennos, A. R., and A. van Casteren. "Transverse stresses and modes of failure in tree branches and other beams." Proceedings of the Royal Society B: Biological Sciences 277, no. 1685 (December 16, 2009): 1253–58. http://dx.doi.org/10.1098/rspb.2009.2093.

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The longitudinal stresses in beams subjected to bending also set up transverse stresses within them; they compress the cross section when the beam's curvature is being increased and stretch it when its curvature is being reduced. Analysis shows that transverse stresses rise to a maximum at the neutral axis and increase with both the bending moment applied and the curvature of the beam. These stresses can qualitatively explain the fracture behaviour of tree branches. Curved ‘hazard beams’ that are being straightened split down the middle because of the low transverse tensile strength of wood. By contrast, straight branches of light wood buckle when they are bent because of its low transverse compressive strength. Branches of denser wood break, but the low transverse tensile strength diverts the crack longitudinally when the fracture has only run half-way across the beam, to produce their characteristic ‘greenstick fracture’. The bones of young mammals and uniaxially reinforced composite beams may also be prone to greenstick fracture because of their lower transverse tensile strength.

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Tsugiyuki, Okuya, Masayuki Nakada, and Yasushi Miyano. "Temperature dependence of longitudinal tensile strength in unidirectional carbon fiber-reinforced plastic." Journal of Composite Materials 48, no. 28 (December 2, 2013): 3569–73. http://dx.doi.org/10.1177/0021998313512349.

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Garalevičius, Romualdas, Romualdas Kliukas, and Adolfas R. Garalevičius. "STRENGTH AND DEFORMABILITY ESTIMATION OF CENTRIFUGED CONCRETE/ОЦЕНКА ПРОЧНОСТО И ДЕФОРМАТИВНОСТИ ЦЕНТРИФУГИРОВАННОГО БЕТОНА." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 2, no. 8 (December 31, 1996): 73–83. http://dx.doi.org/10.3846/13921525.1996.10590175.

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Influence of several factors, namely high strength longitudinal reinforcement, transverse (spiral) reinforcement, precompression level and concrete age, on mechanical properties of centrifuged concrete is investigated. It has been established by tests that longitudinal and transverse (spiral) reinforcement make worse compaction, casting and hardening conditions of centrifuged concrete. But the spiral reinforcement reduces transverse deformations of compressed centrifuged members of ring cross-section and hence increases concrete strength. During the experiments for central compression, centrifuged concrete members of a ring cross-section were investigated. The parameters of these members: diameter 260 and 500 mm, height 400 and 800 mm, web thickness 35…80 mm. The specimens were reinforced by longitudinal bars of 10, 12, 14 mm diameter and 4 or 5 mm cross-section spirals. Coefficient of longitudinal reinforcement μ s , varied from 1,5 to 6%, coefficient of transverse reinforcement μ cir —from 0,25 to 1,25%, lead of spirals—from 40 to 100 mm. During testing the ring concrete compressive strength Rb was 30…60 MPa. The results of the above-mentioned experiments are presented in Tables 1, 2 and 3. It is recommended to evaluate the reinforcement influence on mechanical properties of such concrete in members of real constructions by formulas (5) and (6). Relationships of concrete strength, initial modulus of deformation and intensity of precompression (9) and (10) are discussed in this article. The latest test results on relationship between concrete compression, tension strength and concrete age are presented. It is established, that hydration of cement takes quite a long time and compression and tension strength of centrifuged concrete increases. This increase in strength is given in Table 4. The strength of centrifuged concrete of 14, 120, 240 and 360 days was determined by direct compression and tension of concrete rings (Table 4). After 9,600 days (26 years) due to a limited number of specimens (concrete rings) the compressive strength was determined by testing prisms cut from the rings. The tensile strength was determined indirectly—by cutting these prisms, as it is recommended by a standard [11] according to formula (12). The results of these tests are presented in Tables 5 and 6. Theoretical connection between tensile and compressive strength may be described by Ferret formula (13), which we propose to use in a slightly changed form, i. e. as (14). Comparative calculations showed that the centrifuged concrete strength calculated according formula (14) corresponds to the results of direct testing (Table 7).

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Quapp, K. M., and J. A. Weiss. "Material Characterization of Human Medial Collateral Ligament." Journal of Biomechanical Engineering 120, no. 6 (December 1, 1998): 757–63. http://dx.doi.org/10.1115/1.2834890.

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The objectives of this study were to determine the longitudinal and transverse material properties of the human medial collateral ligament (MCL) and to evaluate the ability of three existing constitutive models to describe the material behavior of MCL. Uniaxial test specimens were punched from ten human cadaveric MCLs and tensile tested along and transverse to the collagen fiber direction. Using load and optical strain analysis information, the tangent modulus, tensile strength and ultimate strain were determined. The material coefficients for each constitutive model were determined using nonlinear regression. All specimens failed within the substance of the tissue. Specimens tested along the collagen fiber direction exhibited the typical nonlinear behavior reported for ligaments. This behavior was absent from the stress–strain curves of the transverse specimens. The average tensile strength, ultimate strain, and tangent modulus for the longitudinal specimens was 38.6 ± 4.8 MPa, 17.1 ± 1.5 percent, and 332.2 ± 58.3 MPa, respectively. The average tensile strength, ultimate strain, and tangent modulus for the transverse specimens was 1.7 ± 0.5 MPa, 11.7 ± 0.9 percent, and 11.0 ± 3.6 MPa, respectively. All three constitutive models described the longitudinal behavior of the ligament equally well. However, the ability of the models to describe the transverse behavior of the ligament varied.

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Dib, Elias, Jean François Caron, Wassim Raphael, Ioannis Stefanou, and Fouad Kaddah. "Numerical analysis and investigation of short- and long-term behavior of unidirectional composites." Journal of Composite Materials 52, no. 5 (June 6, 2017): 659–78. http://dx.doi.org/10.1177/0021998317713355.

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This study gives a detailed analysis on estimating the ultimate tensile strength of unidirectional fiber reinforced composites and its creep behavior under sustained tension load. We develop two different micromechanical models that allow us to estimate the longitudinal tensile strength and the evolution with time of fiber and matrix stresses around arbitrary array of fiber breaks. The first model is based on the shear-lag theory while the second one is developed using the software Abaqus. The comparison of the above models allowed to validate the fundamental assumptions of the shear-lag theory (first model) as well as several numerical issues related to time integration and spatial discretization. The Monte–Carlo method was used in order to account for the stochastic fiber strength and its impact on the ultimate tensile strength (short-term) and creep (long-term behavior) of unidirectional composites. Finally, a parametric investigation on the fiber type and the load level on the long-term behavior of unidirectional composites was performed showing an accelerating creep effect for fibers of inferior quality such as glass fibers compared to carbon fibers.

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Li, Jin, Li Bin Xia, and Qian Liu. "Mechanical Behavior of Flax Knitted Fabric Reinforced Polyurethane Foam Plastics under Tensile and FEM Simulation." Advanced Materials Research 187 (February 2011): 444–47. http://dx.doi.org/10.4028/www.scientific.net/amr.187.444.

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Plain flax knitted fabrics which were divided into three types by different densities were knitted on computerized flat knitting machine in order to investigate the effect of fabric density on composite tensile properties. Flax/polyurethane composite materials which used flax as reinforcement, polyurethane foam plastics as matrix were prepared by reaction injection molding, and tensile tests were carried out in the wale and course directions. The results showed that the addition of knitted fabrics could greatly enhance the tensile properties of polyurethane foam, but the elongation decreased; The tensile strength of composite materials with the same density along the longitudinal direction was higher than the tensile strength along the transverse direction; With the density of the fabric increasing, the tensile strength of composite materials would also increase. Furthermore, tensile process was simulated by finite element software.

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Byun, Joon Hyung, Kyeong Sik Min, Yeun Ho Yu, Moon Kwang Um, and Sang Kwan Lee. "Mechanical Properties of VGCF/PP Nanocomposites by Extrusion and Compression Process." Key Engineering Materials 334-335 (March 2007): 829–32. http://dx.doi.org/10.4028/www.scientific.net/kem.334-335.829.

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This study describes a method of good dispersion and alignment of VGCFs, and examines the effect of nanofiber content on the mechanical properties of nanocomposites. The dispersion of nanofibers was carried out by solution blending, mechanical mixing, and sonication. Levels of 4% – 31% volume content of VGCFs were mixed with polypropylene (PP) powder, and then were melt-mixed using a twin-screw extruder. For the further alignment of fibers, extruded rods were stacked in the mold cavity for the compression molding. In the case of 31% volume content, tensile modulus and strength improved by 100% and 40%, and the flexural modulus and strength increased by 120% and 25%, respectively. The shear modulus showed 65% increase, but the strength dropped sharply by 40%. In the transverse direction, the tensile, flexural, and shear strength decreased as more fibers were added. The matrix modification by maleic anhydride (MAPP) increased the tensile and flexural properties of VGCF/PP by 20% - 30% in the longitudinal direction, and 40% - 250% increase in the transverse direction. The fiber surface treatment by plasma improved tensile and flexural properties of untreated VGCF/PP (18 % vol) composites by 10% - 30% in the longitudinal direction, but strength in the transverse direction decreased by 30% - 40%.

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Li, Chenghu, Wei Guo, and Zhe Wu. "Tensile strength of Z-pinned laminates in RTD and hot-wet environment." Science and Engineering of Composite Materials 24, no. 1 (January 1, 2017): 101–9. http://dx.doi.org/10.1515/secm-2014-0352.

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AbstractExperiments and simulation analysis for tensile strength of Z-pinned laminates were conducted in both room temperature and dry and hot-wet environments. The results of the experiments show that the fracture of [0]6 specimen with Z-pins was longitudinally torn, and there was a row of Z-pins at the fracture of [(±45)/(0,90)]2S specimen with Z-pins. It could be observed that the hot-wet effect on the tensile strength of the Z-pinned laminates increased with percentage of 0-direction fibers decreasing in the laminates from the experiments of the unidirectional tape laminates and the woven cloth laminates. When the volume content of Z-pin increased, the hot-wet effect on tensile strength of Z-pinned [45/0/-45/90]2S laminates with Z-pins would become smaller and smaller. The simulation method of the hot-wet effect on tensile strength of the laminates was combined with the experiment and the finite element analysis. It used 14 nonlinear springs to simulate the longitudinal tearing of [0]6 specimen with Z-pins. The simulation results showed that Z-pin played a role of fulcrum, and because of the lever principle, the fiber bundles were torn at both tips in resin-rich area.

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Yamamoto, Ei, Kozaburo Hayashi, and Noritaka Yamamoto. "Effects of Stress Shielding on the Transverse Mechanical Properties of Rabbit Patellar Tendons." Journal of Biomechanical Engineering 122, no. 6 (June 29, 2000): 608–14. http://dx.doi.org/10.1115/1.1319660.

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With the aim of studying mechanisms of the remodeling of tendons and ligaments, the effects of stress shielding on the rabbit patellar tendon were studied by performing tensile and stress relaxation tests in the transverse direction. The tangent modulus, tensile strength, and strain at failure of non-treated, control patellar tendons in the transverse direction were 1272 kPa, 370 kPa, and 40.5 percent, respectively, whereas those of the tendons stress-shielded for 1 week were 299 kPa, 108 kPa, and 40.4 percent, respectively. Stress shielding markedly decreased tangent modulus and tensile strength in the transverse direction, and the decreases were larger than those in the longitudinal direction, which were determined in our previous study. For example, tensile strength in the transverse and longitudinal direction decreased to 29 and 50 percent of each control value, respectively, after 1 week stress shielding. In addition, the stress relaxation in the transverse direction of stress-shielded patellar tendons was much larger than that of non-treated, control ones. In contrast to longitudinal tensile tests for the behavior of collagen, transverse tests reflect the contributions of ground substances such as proteoglycans and mechanical interactions between collagen fibers. Ground substances provide lubrication and spacing between fibers, and also confer viscoelastic properties. Therefore, the results obtained from the present study suggest that ground substance matrix, and interfiber and fiber–matrix interactions have important roles in the remodeling response of tendons to stress. [S0148-0731(00)00806-2]

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Strakna, T. J., S. Jahanmir, R. L. Allor, and K. V. Kumar. "Influence of Grinding Direction on Fracture Strength of Silicon Nitride." Journal of Engineering Materials and Technology 118, no. 3 (July 1, 1996): 335–42. http://dx.doi.org/10.1115/1.2806815.

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It is generally found that grinding transverse to the tensile stress direction in flexure bars subjected to four-point bending results in a lower strength compared to grinding in the longitudinal direction. In the present study, standard flexure specimens made from a reaction-bonded and a sintered reaction-bonded silicon nitride (RBSN and SRBSN) were surface ground under three different conditions in both longitudinal and transverse directions to assess the effect of grinding direction on strength. Four-point flexure tests were performed on the specimens and Weibull parameters were calculated. The results showed that while the strength was not affected by the grinding condition when grinding was performed in the longitudinal direction, the strength of the samples ground in the transverse direction was reduced as the material removal rate was increased by a factor of 30. This result was confirmed by fractography, which showed that almost all the fracture initiation sites in the longitudinally ground samples were associated with near-surface microstructural features, whereas in the transverse ground samples fracture initiated from damage introduced by grinding. The strength reduction by grinding in the transverse direction was found to be material dependent, and was larger for SRBSN than for RBSN.

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Gurova, T., J. R. Teodòsio, J. M. A. Rebello, and V. Monin. "Variation of the residual stress state in a welded joint during plastic deformation in a 5.0%Cr and 0.5%Mo steel." Journal of Strain Analysis for Engineering Design 32, no. 6 (August 1, 1997): 455–59. http://dx.doi.org/10.1243/0309324971513553.

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The aim of the present work is to verify the variation of the initial residual compressive stress induced by shot-peening, during plastic deformation under uniaxial tension, in a steel with 5.0%Mo and 0.5%Cr, employing test pieces taken from a welded joint where, due to the welding process, there are regions with different mechanical properties (yield strength and tensile strength). The regions of the joint, the base metal, the heat-affected zone and the weld bead exhibited different behaviour. In the heat-affected zone the residual compressive stresses in the longitudinal direction changed to tensile stresses with 0.5-1 per cent plastic deformation. At 3 per cent the stresses attain a maximum tensile value, decreasing in an oscillating manner up to 6 per cent plastic deformation. Beyond this point the test pieces reached a constant tensile value until the fracture. The transverse residual stress values were also modified during the tensile test but no full stress relaxation was observed. Indeed, the initial compressive stress values changed under small applied plastic deformation and after 4 per cent plastic deformation they changed weakly until the test piece fracture. The weld bead was weakly deformed and no effective stress relaxation was observed. In both the longitudinal and the transverse directions, the residual compressive stresses are brought sharply from an initial value of — 470MPa to a minimum of — 250MPa for only 0.5 per cent plastic deformation. No further changes were observed until the fracture of the test piece.

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Ahn, Sang Bok, Do Sik Kim, Young Suk Kim, Dong Joon Oh, and Jung Kyu Kim. "Irradiation and Operating Temperature Effects on the Tensile Characteristics of CANDU Pressure Tube Material." Key Engineering Materials 297-300 (November 2005): 421–27. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.421.

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To investigate the degradation of mechanical properties induced mainly by neutron irradiation and operating temperatures, tensile tests were conducted from room temperature to 300°C using irradiated and unirradiated Zr-2.5Nb pressure tube materials. The irradiated longitudinal and transverse specimens collected from the coolant inlet, middle and outlet parts of the tube which had been operated in the CANDU reactor and showed different operating temperatures and irradiation fluence. The different tensile behavior was characterized by the tensile loading direction in the unirradiated tube. The transverse specimen showed higher strength and lower elongation than those of the longitudinal one. The increased strength hardening and the decreased elongation embrittlement of the irradiated material were compared to those of the unirradiated one. While the tensile strength of the inlet was higher than that of the outlet, the elongation of the inlet was lower than that of outlet. Considering the operation condition, it was proposed that the operating temperature could be a more effective parameter than the irradiation fluence for long-time life. Through TEM observation, it was also found that while the a-type dislocation density was increased, the c-type dislocation was not changed in the irradiated material. The fact that the higher dislocation density was sequentially distributed over the inlet to the outlet parts was consistent with the distribution of the tensile strength.

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Liu, Gui Rong, Shi Hai Xiang, Xiao Ke Li, and Shun Bo Zhao. "3-D FE Analysis on Loading Performance of Tunnel Under-Across Main Canal of South-to-North Water Transfer Project." Applied Mechanics and Materials 438-439 (October 2013): 991–95. http://dx.doi.org/10.4028/www.scientific.net/amm.438-439.991.

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Under the background of engineering application, a 3-D FE analysis was carried out to evaluate the loading performance of a two-hole pair-arch tunnel under-across the main canal of South-to-North Water Transfer Project. In fact, the tunnel was constructed in integral longitudinally without obeying the design requirement of parting within certain length. The analysis showed that the vertical deformation and tensile stress along the longitudinal axis are obviously affected by the loads from main canal, moreover, the tensile stress exceeds the limit of tensile strength of concrete, which may lead thoroughly cracks on top plate of tunnel. This analysis determined the crack zone which should be dealt with.

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Paramsothy, Muralidharan, Xing He Tan, Jimmy Chan, Richard Kwok, and Manoj Gupta. "Si3N4 Nanoparticle Addition to Concentrated Magnesium Alloy AZ81: Enhanced Tensile Ductility and Compressive Strength." ISRN Nanomaterials 2012 (November 29, 2012): 1–8. http://dx.doi.org/10.5402/2012/169850.

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This study is aimed at understanding the tensile ductility and compressive strength-enhancing dual function of nanoparticles in a concentrated magnesium alloy (AZ81) nanocomposite. Si3N4 nanoparticles were selected for reinforcement purposes due to the known affinity between magnesium and nitrogen. AZ81 magnesium alloy was reinforced with Si3N4 nanoparticles using solidification processing followed by hot extrusion. The nanocomposite exhibited similar grain size and hardness to the monolithic alloy, reasonable nanoparticle distribution, and nondominant (0 0 0 2) texture in the longitudinal direction. Compared to the monolithic alloy in tension, the nanocomposite exhibited higher failure strain (+23%) without significant compromise in strength, and higher energy absorbed until fracture (EA) (+27%). Compared to the monolithic alloy in compression, the nanocomposite exhibited similar failure strain (+3%) with significant increase in strength (up to +20%) and higher EA (+24%). The beneficial effects of Si3N4 nanoparticle addition on tensile ductility and compressive strength dual enhancement of AZ81 alloy are discussed in this paper.

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Hamed, Gary R., and Kanoktip Boonkerd. "EFFECT OF CURE EFFICIENCY ON PROPERTIES OF GUM AND BLACK FILLED NATURAL RUBBER VULCANIZATES." Rubber Chemistry and Technology 84, no. 2 (June 1, 2011): 229–42. http://dx.doi.org/10.5254/1.3577535.

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Abstract Effects of the sulfur cure efficiency on the reversion behavior and the normal and edge-cut tensile strength of gum and black filled natural rubber (NR) vulcanizates were studied. N, N-dicyclohexyl-2-benzothiazole sulfenamide (DCBS) was used as an accelerator. A series of five vulcanizates with high to low cure efficiencies was prepared by increasing the sulfur (S) to DCBS ratios within the range of 0.26–6.66. All vulcanizates were formulated to have the same crosslink density. The degree of reversion (%) calculated from cure curves of gum and black filled NR at 20 min above the cure time (tc100) passed through maximum with decreasing cure efficiencies. For both gum and black filled NR, the highest degree of reversion (%) was observed at the S/DCBS ratio of 1.17. The normal tensile strengths of gum and black filled NR were directly proportional to the cure efficiency. For gum NR vulcanizates, the edge-cut tensile strength was markedly influenced by cure efficiency. Similar to the normal tensile strength, the gum NR vulcanizates cured with the lowest cure efficiency showed the lowest edge-cut tensile strength. Effect of the cure efficiency on the edge-cut tensile strength was less in the case of black filled NR vulcanizates. However, the black filled NR vulcanizates cured with the lowest cure efficiency also showed the lowest edge-cut tensile strength. The cut tip characteristics of the fracture specimens were investigated using scanning electron microscopy. The gum specimens showed only the simple lateral cracking pattern, while all black filled specimens showed the longitudinal cracking pattern. Four different cracking patterns of the black filled specimens were identified. The distribution of cracking patterns depended strongly on the size of precut and the cure efficiency.

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Vainiūnas, Povilas. "THE ANALYSIS OF CALCULATION OF PUNCHING STRENGTH OF RC SLABS ACCORDING TO THE DESIGN CODES." Technological and Economic Development of Economy 12, no. 2 (June 30, 2006): 84–90. http://dx.doi.org/10.3846/13928619.2006.9637727.

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The article analyses the calculation of punching strength of RC slabs according to the design codes of various countries. The comparison of experimental and theoretical results is presented. Both experimental and theoretical research confirmed the dependence of punching strength on the longitudinal reinforcement ratio in the tensile zone. While the reinforcement ratio of the tensile zone is higher, the angle of punching pyramid sidewall is less, the critical section is far away from the edge of the column, the critical perimeter is longer and thus the punching strength of the slab is greater.

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BERNARDO, Luís F. A., Miguel C. S. NEPOMUCENO, and Hugo A. S. PINTO. "FLEXURAL DUCTILITY OF LIGHTWEIGHT-AGGREGATE CONCRETE BEAMS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 22, no. 5 (May 17, 2016): 622–33. http://dx.doi.org/10.3846/13923730.2014.914094.

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This paper describes an experimental study on the flexural ductility of lightweight-aggregate concrete beams including concretes with compressive strengths between 22.0 and 60.4 MPa and dry densities between 1651 and 1953 kg/m3. Nineteen simply supported beams were tested until failure. Two symmetrical concentrated loads were applied at approximately one third of the span. Ductility was studied by defining ductility indexes. The main variables are the concrete compressive strength and the longitudinal tensile reinforcement ratio. It is shown that the parameter with higher influence on ductility is the longitudinal tensile reinforcement ratio. The test results are also compared with the requirements from some codes of practice. It is shown that ACI Code requirements give more guaranties as far as ductility is concerned, when compared with European codes.

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Journal articles on the topic 'Longitudinal Tensile Strength'

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