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The mechanical tenacity characterizes the materials behaviour to static and dynamic shocks, at the ambient and the negative temperatures. In the case of deposited metals by welding, the tenacity characterization is made by determining the impact energy, (KV), the crack back contraction, (CBC), the lateral expansion (EL), and the correlation between these characteristics.

Polyamide 5,6 (PA56) fibers were successfully prepared by melt-spinning technique. PA56 fibers were subjected to hot drawing process at different draw ratio and temperature. The effect of the drawing conditions on their mechanical properties such as tenacity, tensile modulus and breaking elongation were investigated by means of tensile test measurements. The results revealed that the tenacity and tensile modulus were found to be increased, while the elongation at break decreased with the draw ratio. The improvements of the mechanical properties could be attributed to the enhanced of the molecular orientation along the fiber axis and an increase in crystallinity. On the other hand, the PA56 fibers mechanical properties do not show significant difference with the drawing temperatures.

This research were examined the spinning processes of paper mulberry yarn and also investigated the physical properties of paper mulberry yarn. The results show that a possibilities of spinning of paper mulberry fiber into yarn which is a longitudinal view similar to that of cotton. An average yarn count, tenacity and elongation are 1,022 tex, 66.39 cN/tex, and 17.80%, respectively. These results represent the beginning of the research to rescue traditional knowledge, combined with the possibility of the introduction of a new textile fiber on the market.

Phenolic fiber is a new fiber and has excellent flame retardant properties. In order to investigate the textile possibility of phenolic fiber and to develop protective clothing and decorative fabrics containing phenolic fiber, the mechanical properties of phenolic fiber were studied firstly, then the polyester fiber was chosen to blend with different portion of phenolic fiber to enhance the strength of the blended yarn and finally the fabrics were knitted with different blended yarns. The strength and wear resistance of different blending ratio of phenolic/polyester blended yarn, and the bursting strength, abrasion resistance and flame retardant properties of the blended fabrics were analyzed and compared. The experimental results shows that the breaking tenacity and elongation at break are low, only 1.3 cN/dtex and 9.4%, respectively, which is not suitable for 100% phenolic fiber to be processed in yarn. The strength and wear resistance of the phenolic/polyester blend yarns and their knitted fabrics increase while the contents of polyester are increased. The flame retardant of phenolic/polyester blend fabrics is improved greatly due to phenolic fiber. Therefore, it is necessary for phenolic fiber to modify its strength and extension in order to be able to get the 100% phenolic yarn and products and in order to give full play to the excellent characteristics of the phenolic fiber.

In order to understand the mechanical properties of the soybean protein fibers (simply called SPF) in different processing condition, the tensile and frictional properties of the SPF are measured with different instruments. By the analysis of the results, the following conclusions can be deduced: bleaching has an influence on decreasing tenacity at break for each test modality. Knotted and looped modalities decrease fiber tenacity remarkably in all three samples, and the same occurs with elongation at break. Looped modalities show lower tenacity and elongation at break, the lowest being the bleached fibers in looped modalities.

This paper has studied the structure and property of high tenacity polyamide 6 upon different draw ratios and heat styling temperature process conditions, characterized with wide-angle X-ray diffraction (WAXD), sound velocity method, Fourier transform infrared (FTIR) spectroscopy, amino-terminated content determination and essential property texts such as the absorption of moisture and dyeing. It was demonstrated that increasing the draw ratio (DR) and heat styling temperature were conducive to crystal-to-crystal transformation and stabilizing the internal structure of fibers. The temperature played a significant role in orientation of high tenacity polyamide 6, particularly subjected to a higher heat styling temperature, owing to its thermo plasticity. And increasing the draw ratio and heat styling temperature were both conducive to the tensile property, but little beneficial impact on moisture property. The high tenacity polyamide 6 exert a good effect on absorption of moisture and acid dye, and for dyeing the effects of hydrogen-bond as well as the van der Waals’ force play a significant role in dye pickup, especially in the high tenacity polyamide 6 upon different draw ratios.

To characterize the performance of Poly(ethylene terephthalate) (PET) fibers of high modulus and low shrinkage (HMLS), static and dynamic mechanical test, DSC, DMA and sonic orientation experiments were carried out. The results indicated that tenacity, initial modulus, Lase-5 decreased and ultimate elongation increased with heat treatment temperature. The dimensional stability of the HMLS fiber is limited by the heat treatment especially when the temperature exceeded Tg because a larger plastic deformation happen with the relaxation of molecular chain in amorphous phase.

In order to study the tensile mechanical properties of the double protein modified fiber. Tensile breaking property and stress relaxation were analyzed and proper mechanical models were selected for fitting. The analysis shows that: in dry and wet, the straight tensile breaking tenacity of the double protein modified fiber is weaker than that of the modified soybean protein fiber, the elongation at break and initial modulus are near to those of the modified soybean protein fiber, the breaking tenacity of the double protein modified fiber increases slightly when wet while the elongation at break and initial modulus decline a little. In knotted and looped, the double protein modified fiber’s tensile breaking tenacity is weaker than that of the modified soybean protein and its tensile breaking strength and elongation at break decrease differently. The fitting reveals that the four element nonlinear viscoelastic model is the best to describe straight tensile. The two optimal models for knotted and looped tensile are the four element nonlinear viscoelastic model and the Improved Zurek model. In addition, the six element viscoelastic plasticity model is appropriate to simulate stress relaxation.

Perilous rock rupture is dominated by damage and fracture of the dominant fissure. Define factor of safety of perilous rock as the ratio of the damage fracture tenacity at the end area of the dominant fissure to the union fracture strength factor; Transfer loads acting on perilous rock to the dominant fissure, and divide them into four components, i.e., water pressure in fissure, average shear stress, moment around the end of the dominant fissure, and average tension stress, further, contribute methods to calculate fracture strength factor every components in view of fracture mechanics; Based on these individual fracture strength factors, establish the method to calculate the union fracture strength factor along fracture orientation near the end area of the dominant fissure. Further, on the basis of damage duration of the dominant fissure, provide the formula to solve the fracture tenacity of rock in damage area near the end of the dominant fissure in detal. Case analyses identify that it is reasonable to consider orientation earthquake force in stability analysis of perilous rock, which promulgates the stability status of perilous rock more effective than that by the limit equilibrium principle.

Steel structure dam, as a newborn dam type in hydropower engineering field, is proposed in this paper. The conception, operating mechanism, bar concection and the design and calculation methods are introduced. The characteristics of the steel braced frame that overall force and stability are fully utilized, and also the steel properties, such as high strength, high tenacity and high wearing. As a new technique and method, it opens up a new way for the application of rich steel resources in the hydropower engineering, which shows a good development prospects.

Alginate fibre has attracted great attention in the area of biological medical materials due to its unique biological properties. But its low tenacity greatly hinders its application area. Therefore, the preparation technology of alginate fibre has been as an important research direction in this area in recent years. The purpose of this article is to prepare the calcium alginate fibre with good properties by wet spinning. The structure and properties of this fibre are analyzed by scanning electron microscope，infrared spectrometer，thermal gravimetric analyzer and DSC.

Limited studies exist related to the siro-spun spinning of flax ( Linum usitatissimum L.) and cotton (Gossypium hirsutum) blends. The purpose of this study was to determine the influence of various siro-spun processing parameters, including twist factor, space between two rovings and specification of traveler, on yarn qualities, such as yarn hairiness, tenacity and evenness. Results show that both specification of traveler and space between two rovings significantly influenced yarn hairiness and evenness, and heavier traveler and greater space led to decreased hairiness, but bad evenness. Twist factor influenced yarn evenness highly significantly, and smaller twist factor led to worse yarn evenness. Results also indicate the optimum levels of siro-spun process parameters as follows: twist factor αm = 150, space between two rovings 8 mm, traveler Fo 5/0. In relation to the general ring-spinning yarn, the siro-spun spinning yarns had decreased hairiness, little increased tenacity and similar evenness.

In this paper, Wide Angle X-ray Diffraction (WAXD), Small Angle X-ray Scattering (SAXS), Dynamic Mechanical Analysis (DMA) and mechanical testing were employed to characterize the effect of heat treatment under constrained condition on poly(ethylene terephthalate) (PET) fiber. The microstructure and property of the PET fiber with moderate tenacity changed with the heat treatment temperature from 110 °C to 190 °C. No change happened in the crystalline phase while the micro-crystal formed in the amorphous phase from the result of crystalline parameters, which led to the increase of Tg of the fiber. The decrease of the tenacity is due to the decrease of the amorphous orientation and the decrease of the long period leads to the increase of the stability of the fiber.

In order to study the effect of different blended ratios on strength and elongation properties of Outlast/viscose blended yarn, ten kinds of blended yarns had been designed and spun. The blended ratios were Outlast/viscose 0/100, 15/85, 25/75, 30/70, 35/65, 40/60, 45/55, 50/50, 60/40, 100/0. By testing the strength and elongation properties of the blended yarn, the effect of blended ratio on blended yarn’s breaking tenacity and elongation rate was analysed. The results showed that, with the increase of blended ratio, the breaking tenacity and breaking elongation rate of the blended yarn both presented a downward trend. But when Outlast/viscose blended ratio was 35:65, breaking elongation rate had a maximum value. When blended ratio was 45:55, breaking tenacity had a maximum value, which should be used in practice.

Calcium alginate fibers and nano-silica/calcium alginate blend fibers were prepared by the mean of wet spinning at the same spinning condition. The effect of nano-particles SiO2 on the structure and properties of alginate fibers were studied via many tests. The results showed that the tenacity of blend fibers increased with the growth of the content of SiO2 ranging from 1% to 5%, however, the tenacity of fibers became worse when the content of SiO2 was more than 5%. The effect of SiO2 content on hardness and tribological properties of the calcium alginate fiber was studied. The morphologies of the fibers surfaces were examined with a Scanning Electron Microscope (SEM). The result showed that the surface of blend fibers was still smooth when the consent of SiO2 not up to 7%, the best surface was obtained when SiO2 content was 5%. The incorporation of SiO2 also affected the absorption property of alginate fiber and made it decrease with the increase of SiO2 content. The structures of calcium alginate fibers and nano-silica/calcium alginate blend fibers were studied by infrared spectrum.

The pineapple leaf fiber is abundant in the tropics and subtropics regions in the world. The raw pineapple leaf fiber needs to be degummed before spinning. In this paper, the effect of alkali treatment on fiber property was studied. Compared to the fiber that not treated by alkali, fiber property improved by alkali treatment. At the same time, the influence of parameters of alkali treatment on fiber property was also discussed. With the concentration of sodium hydroxide solution increasing, the fineness, the tenacity, and the breaking elongation of pineapple fiber are all decreased. The effect of time on the fineness of degummed pineapple fiber is insignificant. With the increase of time, the tenacity of pineapple fiber is decreased slightly. However, the breaking elongation of pineapple fiber decreased at first, and then increased. As the temperature increase, the fineness of pineapple fiber increased then decreased. On the contrary, with the temperature increasing, the tenacity of pineapple fiber decreased firstly, and then increased. The breaking elongation of pineapple fiber decreased with the increase of temperature.

In order to release the relationship between technics variables and properties of PAN fiber, the evolvement of crystalline structure of PAN fiber during the wet spinning process was studied by X-ray diffraction(XRD), the measurement of the solvent residuals, boiling-water shrinkage and breaking tenacity. It is found that the drawing and removal of solvent can improve the tenacity, especially the drawing can improve degree of orientation and crystallinity, and the collapse process can stabilize the orientation and crystalline structure.

Light weight , softness and comfort are becoming the development priority for the bast fabrics for apparel use. Therefore, some properties of the bast fabers related to these aspects become important. In this paper, the properties of bast fibers, including fiber length, fineness, tenacity, softness were tested and evaluated to determine which is better for developing fabrics pleased by the consumers by using optimal design theory. The results show that ramie fiber has high softness, great tenacity and is finest. It is the best material for the garments required light weight and comfort, hemp second, the next is flax and kenaf. Jute is the worst one.

The ultra-fine denier PET full drawing yarn (PET-FDY) with monofilament linear density equal to 0.38dTex was produced. During the practical process of ultrafine denier PET-FDY, the yarn should be heat-set at certain temperature following the drawing process in order to improve the mechanical properties and reduce the boiling water shrinkage. The influence of heat-setting temperature on the structure and performance of ultra-fine denier PET FDY was studied in this paper. With heat-setting temperature increasing, crystalline in PET FDY became perfect and crystallite size became bigger. According to the density method, crystallinity was augmented. Crystal orientation factor and overall orientation factor were both increased. The tenacity and tensile stress at 10% strain of PET FDY were increased and the breakage percentage and boiling water shrinkage were reduced with the heat-setting temperature increasing.

The drawing properties of the modified PA 6 (MPA) fiber specimens prepared at varying drawing temperature were systematically investigated, wherein the MPA resins were prepared by reactive extrusion of PA 6 with the compatibilizer precursor (CP). At any fixed drawing temperature, the achievable draw ratio (Dra) values of MPA as-spun fiber specimens increase initially with increasing CP contents, and then approach a maximum value, as their CP contents are close to the 5 wt% optimum value. The maximum Dra values obtained for MPA as-spun fiber specimens prepared at the optimum CP content reach another maximum as their drawing temperatures approach the optimum drawing temperature at 120 °C. The tenacity and birefringence values of PA 6 and MPA fiber specimens improve consistently as their draw ratios increase. Similar to those found for their achievable drawing properties, the ultimate tenacity and birefringence values of MPA fiber specimens approach a maximum value, as their CP contents and drawing temperatures approach the 5 wt% and 120 °C optimum values, respectively. Investigations including Fourier transform infrared, melt shear viscosity, gel content, thermal and wide angle X-ray diffraction experiments were performed on the MPA resin and/or fiber specimens to clarify the optimum CP content and possible deformation mechanisms accounting for the interesting drawing and ultimate tensile properties found for the MPA fiber specimens prepared in this study.

The natural color silk has been treated by sodium hydroxide and sodium carbonate，and the structure, crystallize and mechanical properties of the treated natural color silk were studied. The results showed that the structure of natural color silk was not changed and the degree of crystallinity decreased; the crystallinity of un-treated natural color silk was 44.4%, while the crystallinities of natural color silk treated by sodium hydroxide and sodium carbonate were 35.2% and 43.6%, respectively. The breaking tenacity and the breaking elongation of natural color silk treated by sodium hydroxide dropped dramatically and the Young’s Modulus declined; but these properties of natural color silk were not changed significantly after being treated by sodium carbonate.

As the single-end tenacity and elongation test of raw silk is required strongly by the raw silk customers instead of the skein test, some basic studies on this kind of testing means were made. The affecting factors on the distribution and statistical characteristics of the single-end tenacity and elongation test of raw silk were studied; and those factors include the draw speed and line density. Investigations in the article are hoped to bring useful help to the establishment of the testing method and testing standards of this kind of testing means.

To research basic property of Shengma fibre（green textile fiber）, basic property of Shengma and viscose were tested and analysed. Through analysing and contrasting each property it is considered that under normal temperature and dry condition, breaking tenacity of Shengma is less than that of viscose, while breaking elongation rate of Shengma is larger than that of viscose. In wet condition change of Shengma fibre mechanical property is less than that of viscose. Crimpability of Shengma fibre is worse than that of viscose.

Basalt filament yarn is a new type of high-performance fibers, which is formed by the direct drawing of basalt rock at high temperatures. It is a natural and environmentally friendly textile material. This paper mainly focuses on thermal resistance research of basalt filament yarn that is heated at various temperatures. The change of color and appearance of heated basalt filament yarn was described. The mechanical properties of heated basalt filament yarn were tested. The results showed that although the mechanical properties of basalt filament yarn decreased with the temperature rising, still remained high tensile strength within a certain temperature range. Basalt filament yarn possess higher tenacity under 325°C. Basalt filament yarns still possess certain tenacity when they were placed at 500°C condition. So basalt filament yarn can be used as heat-resistant materials, such as filtration materials for high-temperature gas and liquid, fire-proof fabrics and so on.

The soybean protein fiber is a new textile material. Thanks to its fine denier, light specific gravity, high strength and silk-like luster，it has so excellent cashmere handle, silk softness and heat resistant properties that it has been called manmade cashmere and found wide application. In order to understand the relationship between the inner structure and the mechanical property and the effect of bleaching and dyeing to the soybean protein fibers，four mechanical models are chosen. The tensile and relaxation property of the soybean protein fibers are analyzed. The tensile and relaxation cures are fitted with the suitable model. It shows that the relaxation property of SPF is in accordance with the standard linear solid model. Estimates of the Hookean spring modulus at 8% and at 10% are different, so some structural modifications could be produced by the strain. Bleached fibers show a higher level of relaxation than raw fibers and dyed fibers. Bleaching has a remarkable influence on decreasing tenacity at break for each test modality. Knotted and looped modalities decrease fiber tenacity remarkably in all three samples.

Portland cement, silica fume and superplasticizer were used to obtain high strength mortar with lower water to binder ratios and suitable binder to sand ratios. The splitting tensile strength and the rupture strength of the high strength mortar were improved further by a type of arc-shaped steel fiber when the content of steel fiber was 3-6.5 vol. %. The results indicated that the tenacity of the high strength mortar improved significantly by the steel fiber.