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In Japan, where a safe and secure society has been established, stab proof clothing that are suitable for police and security officers supporting are required. So far, most of the stab-proof clothing is made of the metal plate or thick multi-layered fabric with high-strength fibers. It is commonly used as a stab-proof vest because it cannot cope with the large deformations, which caused by the joints such as arms or neck. This research aims to develop high flexible stab-proof clothing that can be applied in large-deformation part such as joints with high stab-proof performance. We developed a testing device that can measure bending characteristics under the same conditions as when the stab proof clothing is actually worn on the human body. The usefulness of the evaluation method was confirmed. And the factors that affect the bendability of the elbow joint were also be studied. The mechanical properties of the material and the gap between the arm and the cylindrical structure are greatly affected, and the effect of each bending angle on the bending moment is different. We considered the deformation of the material when it bending and then proposed a new stab-resistant material structure and trial production. The cylindrical bending test shows that the flexibility of the new structure is greatly improved. [ABSTRACT FROM AUTHOR]

Addition of oxygen in the interface between Cu and Al 2 O 3 can significantly improve the wettability. In the present work, Cu/Al 2 O 3 laminated composites were fabricated by bonding Cu foils with CuO-coated Al 2 O 3 plates. Before bonding, the coated Al 2 O 3 plates were pretreated at different temperature in the air. The effect of pretreated temperature on the interfacial microstructure, wettability and bending property were investigated. Phase composition in the interface after wetting test was characterized according to the thermodynamics of Cu–O system. The wetting mechanism and bending failure mode of Cu/Al 2 O 3 laminated composites were also analyzed. Pretreated temperature significantly influences the wettability and bending strength of the composites. The contact angle decreased to about 22° when the pretreated temperature equal to 1100 °C. Continuous CuAlO 2 in the interlayer is beneficial to the wettability between Cu melt and Al 2 O 3 , while other phases such as Cu 2 O and CuAl 2 O 4 would increase the contact angle. Crack formation and propagation are the main failure mode of Cu/Al 2 O 3 laminated composites during bending test. Different from the wettability, Cu/Al 2 O 3 laminated composites fabricated with pretreated temperature at 1050 °C show the highest bending strength, although the contact angle is not the lowest on this condition. The reason is illustrated through analyzing the bending failure mode. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The burnished surface quality of a Ni-based alloy was investigated. For this, we developed and utilized a sliding burnishing process with an active rotary diamond-like carbon-coated carbide tool. Two kinds of Ni-based alloys subjected to solution heat and aging heat treatments were used as workpiece materials. The burnished surface quality was evaluated based on the roughness and profile of the surface, hardness, and the microstructure of the subsurface, residual stress, and full-width at half maximum based on X-ray analysis, and bending property of the testpiece. The preliminary surface, which was finished by filing, was also evaluated for comparison. A smooth-finished surface of approximately Ra = 0.1 μm or less was obtained by the burnishing process in both materials. The subsurface hardness of the solution heat-treated material was increased by the burnishing process, and it was also observed to increase with the thrust force as a burnishing condition, while the influence of the burnishing process on the subsurface hardness at a depth of 20 μm or more from the surface was hardly observed in the aging heat-treated sample. A large compressive residual stress and the full-width at half maximum can be obtained for the burnished surface. Based on the three-point bending test using the solution heat-treated material, the yield load transitioned from the elastic to the plastic region increased and the bending strength also clearly increased due to the burnishing process for a thrust force of 100 N. The developed sliding burnishing process with diamond-like carbon-coated carbide tool can yield a high-quality surface with low roughness, high hardness, and large compressive residual stress of Ni-based alloys based on solution heat treatment and aging heat treatment, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to promote plantation establishment of Larix gmelinii var. olgensis (syn. L. olgensis A. Henry), a 'near threatened' species, the wood and lumber properties were preliminary investigated for five trees from two clones of 57-year-old trees planted in Japan. The mean value of dynamic Young's modulus of logs was 10.16 GPa. The mean values of annual ring width, latewood percentage, basic density, MOE, and MOR of five sample trees were 2.1 mm, 29.3%, 0.47 g•cm-3, 8.06 GPa, and 60.4 MPa, respectively. In addition, the MOE and MOR of 2 by 4 lumber were 10.43 GPa and 42.4 MPa, respectively. These values were similar to those obtained from other Larix species. Thus, construction lumber could be produced from the wood from plantation grown L. gmelinii var. olgensis. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) woven spacer composites are competitive materials in aerospace fields due to their excellent integrated, light-weight structure. The face sheets of the 3D woven spacer composites are crucial for the mechanical properties. In this study, 3D hybrid composites, which are composed of glass and carbon fibers in the face sheets and glass fiber in the core layer as reinforcement and epoxy resin as the matrix, were designed and fabricated. The bending test results show that with the increase of the carbon fibers in the face sheets, the normalized bending strength of hybrid spacer composites showed limited improvement, while their normalized bending moduli and bending stiffnesses were significantly improved. The optical and scanning electron microscope images of the fractured surfaces reveal that the fibers in the top face sheet, which is under compression by the indenter, are damaged first and cause the failure of the entire structure, whereas the fibers in the bottom face sheets are stretched during the bending test and slightly damaged. In addition, in the failure cross-sections, pull-out of the carbon fibers is observed due to its limited interfacial bonding with the epoxy resin. This work could help optimize 3D hybrid woven spacer composite structures for better performance and lower cost. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian Polytechnic University is the property of Journal of Dalian Polytechnic University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Thermoplastic composites have a wide range of applications in the industrial field. However, it is challenging to achieve three-dimensional (3D) multi-layer thermoplastic composites due to the poor impregnation of highly viscous thermoplastic resins. Herein, we propose a new preparation method to obtain 3D carbon fiber/PEEK (CF/PEEK) composites with exceptional mechanical properties. CF/PEEK prepreg was used as the warp and weft yarns, and the Kevlar yarn was used as Z-yarns to weave 3D orthogonal preform through a self-made loom. 3D CF/PEEK composites were completed by hot-pressing process with varied resin contents from 37 wt% to 46 wt%. When the resin content was 43 wt%, the CF/PEEK composites exhibited the largest bending strength, with values of 248.5 MPa and 657.12 MPa along the warp and the weft directions, respectively. Additionally, the as-prepared 3D CF/PEEK composites could not be ignited and could retain around 90.67% of its original bending strength even after being subjected to the flame of an alcohol burner for 360 s. This work provides a novel method for fabricating 3D thermoplastic composites, a promising material in the field of high-performance composites. [ABSTRACT FROM AUTHOR]

Material extrusion of thermoplastic polymers enables the realization of complex specific designs with high performance composites. The present study aims at evaluating the mechanical properties of carbon fiber-reinforced semi-crystalline thermoplastic polymer polyether ether ketone (CFR-PEEK) manufactured by material extrusion and correlating them with results obtained by micro-CT. Samples in the shape of small bars were provided by Kumovis (Munich, Germany). The determination of surface roughness and density was followed by three-point bending tests. To reveal the pore distribution as well as the fusion quality of CFR PEEK when applied with external forces, micro-CT scans were performed with an X-ray microscope before and after the mechanical test to localize the sites where the fracture is generated. The density of CFR-PEEK bars indicated that they had superior mechanical properties compared with our previous study on unfilled 3D printed PEEK (bending modulus: (5.4 ± 0.5) GPa vs. (1.05 ± 0.05) GPa to (1.48 ± 0.10) GPa; bending strength: (167 ± 11) MPa vs. (51 ± 15) to (193 ± 7) MPa). Micro-CT analyses revealed the local 3D-distribution of voids. Voids of 30 μm diameter are nearly spherical and make up the main part of the total porosity. The larger the voids, the more they deviate from a spherical shape. Significant lack-of-fusion voids are located between the deposited filaments. By growing and merging, they act as seeds for the forming fracture line in the region of the flexural specimens where the maximum local tensile stresses occurred under bending load. Our work provides a detailed analysis of printed PEEK with fiber additive and relates this with mechanical properties. [ABSTRACT FROM AUTHOR]

The modification effect of pineapple leaf nanocellulose cooperating with SiO2 gel on linen blended fabric was studied. The thickness, breaking strength, bending property, air permeability and creasy recovery angle of linen blended fabric before and after the modification of pineapple leaf nanocellulose cooperating with SiO2 gel with different concentrations were tested. The test results showed that the thickness of Nano SiO2 gel modified linen blended fabric was increased as the increase of the mass fraction for pineapple leaf nanocellulose. The breaking strength and creasy recovery angle was increased first then decreased. The bending property was strengthened and the air permeability were decreased. It is considered that the modification effect on fabric overall properties is better when 0. 5 % mass fraction pineapple leaf nanocellulose cooperating with SiO2 gel is adopted for the improvement of linen blended fabric. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of laser heat treatment on the bending property of low-alloy ultrahigh strength steel laser-welded joints. A laser rectangular spot is used for local heat treatment. The results indicate that the back bending angle of joints can be improved from 30° to over 90° with a joint efficiency of 76%. With the increase of laser power and scanning times and the decrease of scanning speed, the heat treatment temperature at the back of the joint increases gradually. The peak temperature under different parameters changes from 450 to 700 °C, at which tempering takes place. This is consistent with the microstructural evolution from original lath martensite of weld metal and heat-affected zone to tempered martensite after laser heat treatment. The hardness between weld and softened zone is similar under the same parameters. Analysis of variance reveals that the hardness is mainly influenced by the peak temperature instead of heating time. The weld hardness decreases gradually with the increase of the peak temperature, and hardness less than 35.0 HRC is obtained when that temperature is over 600 °C. The weld hardness is closely related with the bending property of joints. When the hardness is less than 35.0 HRC, a bending angle over 90° can be achieved. This is because laser tempering makes the hardness of joints uniform, consequently improving the bending performance of the joints. [ABSTRACT FROM AUTHOR]

In this study, the influence of silane addition on mechanical properties of epoxy/3D orthogonal glass fiber woven composite was studied. The KH560 silane modification composite specimen reinforced with 3D orthogonal woven fabric/epoxy was manufactured by means of Resin Infusion under Flexible Tooling. The mechanical properties of the epoxy/3D glass fiber woven composites were characterized by tensile and bending tests. The tensile and bending properties of silane-modified 3D orthogonal woven glass composite in warp and weft directions were compared with the pristine or epoxy/glass composite material not coupled using silane. The results show that the tensile and bending properties in warp and weft directions have been improved due to the silane addition. The bonding strength between the fiber and matrix was improved and the delamination and debonding between fiber and matrix was retarded and shifted to cohesive failure of the matrix due to the silane modification. Electron microscopy of the fracture and failure modes of the test specimens were used to support the results and conclusions. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Physics is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, composites of poly (hydroxybutyrate-co-valerate) (PHBV) with untreated luffa fibers (ULF) and NaOH-H2O2 treated luffa fibers (TLF) were prepared by hot press forming. The properties of luffa fibers (LFs) and composites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and other analysis methods. Results showed that pre-treatment effectively removed pectin, hemicellulose, and lignin, thus reducing the moisture absorptivity of LFs. The flexural strength of TLF/PHBV was higher than that of ULF/PHBV. With 60% LF content, the flexural strengths of ULF/PHBV and TLF/PHBV reached 75.23 MPa and 90.73 MPa, respectively, 219.7% and 285.6% more than that of pure PHBV. Water absorptivities of composites increased with increase in LF content. Water absorptivity of TLF/PHBV was lower than that of ULF/PHBV. The flexural strengths of composites decreased after immersion in water at room temperature. Meanwhile, flexural strength of TLF/PHBV was lower than that of ULF/PHBV. Pretreatment of LFs effectively improved the bonding between fibers and PHBV, resulting in enhanced and thus improved the moisture resistance of composites.

In this paper, a polymer-based composite material was prepared by hand Lay-up method consisting of epoxy resin as a base material filled with by magnesium oxide powder once and silicon dioxide powder again and with different weight ratios (3%, 6%, 9%, 12%). The three-point bending test was performed in normal conditions and after immersion in sulfuric acid. The results showed that the bending value decreased with the increase of the weighted ratio of the filled nano powder (MgO, SiO2) .The Bending of samples filled with by SiO2 was found to be less than the bending of samples filled with by particles (MgO), the bending of the SiO2 sample (0.32mm) at the weighted ratio (3%) and for the MgO (0.18mm) sample at the weight ratio were the same at the same weighted load (100 g). It was found that the bending values of all samples exceeded the value after immersion in sulfuric acid. The percentage of weight (6%) at the load level (500 g) was changed from 1.16mm in normal conditions to 1.48mm for the same weight ratio after immersion. In sulfuric acid diluted with 0.3N for 10 days at the same Applied load. [ABSTRACT FROM AUTHOR]

The wood properties were examined for Larix sibirica naturally grown in Tosontsengel, Mongolia. The dynamic Young's modulus of the logs ranged from 6.31 to 9.65 GPa. The mean values of wood properties were as follows: water-extracted basic density = 0.44 g cm−3, air-dry density = 0.59 g cm−3, shrinkage at 1% moisture content change in the radial and tangential directions = 0.18% and 0.32%, modulus of elasticity = 11.24 GPa, modulus of rupture = 102.4 MPa, compressive strength parallel to the grain = 53.1 MPa, and mass loss by Fomitopsis palustris and Trametes versicolor = 10.4% and 18.6%. Mass loss in the heartwood was higher than that in the sapwood, indicating that the larger mass loss values in the heartwood of L. sibirica might be related to the larger amount of arabinogalactan. [ABSTRACT FROM AUTHOR]

TiAl matrix composites reinforced with Ti2AlN were fabricated by in situ reactive method of powder metallurgy. Microstructures, bending properties at room temperature and compressive properties at elevated temperatures were investigated in contrast with those of TiAl alloy. The results reveal that the microstructure of TiAl matrix is significantly refined due to the synthesis of Ti2AlN. 15 vol.%Ti2AlN/TiAl exhibits excellent bending properties at room temperature, with bending strength of 753 MPa and fracture strain of 0.74%, which are 24.3 and 19.7% higher than those of TiAl alloy. The compressive strength of Ti2AlN/TiAl is markedly improved in comparison to that of TiAl alloy at elevated temperatures. Noticeably, the compressive strength of 15 and 35 vol.%Ti2AlN/TiAl increases by 67.4 and 58.7% at 1000 °C, respectively. The remarkable enhancement of mechanical performance is mainly due to the noteworthy refinement of TiAl matrix and the efficient obstruction of Ti2AlN particles to crack propagation, as well as the effective load-carrying role of Ti2AlN with high elastic modulus. [ABSTRACT FROM AUTHOR]

This study aimed at developing a thermo-hydro-mechanical (THM) processing to compress poplar wood and investigating the effects of high temperature, moisture, and pressure during the THM processing on the changes in microstructure, porosity, mechanical properties, and dimensional stability of compressed poplar wood. The variations in these properties were correlated and their mathematical relations were determined. Poplar woods with high moisture content were compressed using different pressures at a temperature of 160 °C for different periods. The compression level was characterized by the volume compression ratio (CR), which is defined as the ratio of the compression volume and the original volume of sample before and after THM processing. The obtained results indicated that the high pressure of THM process caused the collapsing of wood cell lumens and the developing of a certain amount of fractures in the cell wall. The damage level of wood cells increased with increasing pressure and time. Moreover, the pressure narrowed the cell lumens, which decreased significantly the pore volume in wood substrate. The pore size distribution shifted from the level of macropores to those of mesopores and micropores after THM process. The THM process created superior mechanical property, especially for those with higher CR. Besides, it was revealed that the process decreased dramatically the set recovery of treated woods and improved their dimensional stability. A significant improvement was achieved in terms of the mechanical and physical properties of compressed poplar wood via the structural reformation during the THM process. [ABSTRACT FROM AUTHOR]

2D-T700/E44 composite materials were prepared by improved compression molding process (ICM) then microstructure and properties of the composites were analyzed and summarized by scanning electron microscope (SEM) and electronic universal testing machine. It is found that defects will occur when the process parameters are not controlled properly and the main defects of composite materials include inadequate resin impregnation, weak interlaminar binding force, fiber displacement warping, hole and brittle fracture. Moreover, there are significant differences in the infiltration microstructure, bending properties, and fracture morphology of the composite materials with different defects. When the defects of weak interlaminar binding force and brittle fracture occur, bending properties of composite materials are relatively low, and they are 220 MPa and 245 MPa, respectively, which reach 34.9% and 38.9% of the bending strength of composite material whose defects are effectively controlled. When the process parameters are reasonable and the defects of the composite materials are effectively eliminated, the bending strength can reach 630 MPa. This will lay a foundation for the preparation of 2D-T700/E44 composite materials with ideal microstructures and properties by ICM.

In this study, long-period-stacking-ordered (LPSO) phases were introduced to carbon fiber reinforced magnesium-gadolinium-zinc (Cf/Mg-Gd-Zn) composite by adding Gd and Zn with the atomic rate of 2:1 into the matrix, and a new and practical method of design and optimize the interfacial structure was found. The Cf/Mg-Gd-Zn composite was fabricated by pressure infiltration method, and the influence of the LPSO phases on the microstructure and mechanical properties were investigated. LPSO phases were precipitated both at the interface and in the matrix. The LPSO phases at the interface were long rod-like, whose preferential growth direction was almost perpendicular to the axis of carbon fibers. But the LPSO phases formed in the matrix tended to be long and short rod-like, and arranged in a certain angle with the axis of the adjacent carbon fiber. Because of the LPSO phases, the interfacial structure of the composites was significantly optimized. Therefore, the mechanical properties of Cf/Mg-Gd-Zn composite were improved considerably. Specifically, compared with Cf/Mg composite, the interlaminar shear strength and bending strength of Cf/Mg-Gd-Zn composite were improved by 26.4% and 25.7%, respectively. [ABSTRACT FROM AUTHOR]

In this paper, we study the bending property of the failure rate, reversed hazard rate, mean residual life and mean inactivity time in mixtures. For those four reliability measures, the weak and strong bending properties are studied and discussed, respectively. The results are illustrated with suitable examples, where most of them are relative to the model of proportional reliability measures. [ABSTRACT FROM AUTHOR]

As a novel type of composite structure in recent years, lattice structure with carbon fiber pyramidal truss core being applied to vessel superstructure because of its high stiffness ratio and strength ratio, structure design is the key to joint between superstructure and main hull. To investigate the mechanical property of hybrid joint and to solve the problem of engineering application, two kinds of specimens of hybrid joints are designed and their compressive and flexural properties are tested through experiments. Experimental result shows that lattice structure is weakest when joint carries in-plane compressive load and debonding induced by core macro-shear and facesheet wrinkling can result in buckling. When load alters to out-of-plane normal force, facesheet delamination becomes main failure mode, occurring where stiffness mutation of joint structure turns up, and bearing reaction can bring about resin base of lattice core fracture, further leading to debonding. [ABSTRACT FROM AUTHOR]

The purpose of this study is to clarify the effect of the fiber crimps in braided carbon fiber reinforced plastics pipe (Braid pipe). Braid pipes with different crimp angles were fabricated by using carbon fiber with different fineness for the braiding yarn and different 0° fiber contents. Larger fineness of carbon fiber and/or more content of 0° fiber made the crimp angle larger. The braiding angle was ±45° and 0° fiber (MEY) was inserted between braiding yarns. 0° fiber content was changed as, 0%, 15% and 29%. The effects of crimp on the bending property and the torsion property were investigated comparing with SW pipes with non-crimp structure made by Sheet Winding method. As regarding bending property, Braid pipe performed 75% to 95% of the bending modulus of the SW pipe. With the increase in the crimp angle, the bending modulus was linearly decreased. The longitudinal yarn in Braid pipe with gap between braiding yarns had crimp and bending strength was decreased. The Poisson's ratio of Braid pipe was smaller by 67% than that of SW pipe. The crimp in longitudinal yarn and Poisson's ratio had greater effect on the bending strength than the crimp of braiding yarn. As regarding torsion property, both of the torsion modulus and strength were decreased with the increase in the crimp angle at braiding yarn. The crimp had 2.5 times greater effect on torsion strength than torsion modulus. It was clarified that the effect of crimp at braiding yarn on the mechanical properties depended on the angle between fiber orientation and the principal stress directions.

Flexible devices has received a great attention due to their high portability, lightness, and ease of shape reconfiguration. To achieve high flexibility, controlling the mechanical properties of the substrate materials is of importance. In this paper, we controlled the local flexibility of PET films via UV laser scribing. The bending test of the films revealed that their bending curvatures, the associated mechanical damages, and the required bending forces could be successfully tuned by controlling the number and the depth of the scribed lines. Our simple strategy of using laser scribing will find its usefulness in flexible device applications where high flexibility and mechanical stability are required. [ABSTRACT FROM AUTHOR]

Introduction The aims of this study were to determine the flexibility of ProFile Vortex (VX) and Vortex Blue (VB) files (Dentsply Tulsa Dental Specialties, Tulsa, OK) and then to evaluate and compare their fatigue resistance in artificial single curvature and 2 different artificial double curvature canals. Methods Flexibility of the files (size 25/.04) in bending was assessed according to ISO 3630-1. Both files were subjected to fatigue tests inside artificial canals with a single curvature (group 1: 60° curvature, 5-mm radius) and with 2 different double curvatures (group 2: first [coronal] curve of 60° curvature and 5-mm radius and the second one [apical] of 30° curvature and 2-mm radius and group 3: first curve of 60° curvature and 5-mm radius and the second one of 60° curvature and 2-mm radius). The number of cycles to fracture (NCF) was recorded, and the fracture surface of all fragments was examined with a scanning electron microscope. Results The bending load was significantly lower for VB files than VX files ( P < .05), and the 2 types of files followed different trajectories in identical canals. In group 1, the 2 files had significantly higher NCF than in groups 2 and 3 ( P < .05). Both files had significantly higher NCF in group 2 than in group 3 ( P < .05). In group 1, VB files had fatigue resistance superior to VX files ( P < .05), whereas in groups 2 and 3 their fatigue resistance was not statistically different from each other. The crack initiation of a vast majority of files that fractured in double curvature canals (groups 2 and 3) was localized on either 1 of 2 of the 3 cutting edges. Conclusions Double curvature canals represent a much more stressful and challenging anatomy than single curvature canals, and, in them, fatigue resistance may be affected by the degrees and the radii of curvatures as well as by the bending properties of the files. [ABSTRACT FROM AUTHOR]

Laser surface treatment of 65Mn steel was conducted using a high-power diode laser. Based on the numerical simulation of the temperature field, the distribution of the microstructure and the peak temperature at various depths were analyzed. An empirical model was proposed to predict the hardened depth. The bending property and fracture mechanism were studied. The results indicated that the martensitic microstructure was coarser near the outer surface of the hardened layer owing to the higher peak temperature. The peak temperature decreased exponentially with increasing depth and increased linearly with laser power and the reciprocal of the square root of the scanning rate. The maximum hardness of the laser-hardened layer was approximately 950 HV, and the self-tempering effect decreased the maximum hardness. Because of the higher brittleness of the hardened layer and the concentration of deformation near the hardened layer, the bending properties deteriorated after laser surface treatment. However, the hardened layer increased the resistance to early bending deformation. Tempering at 150 °C slightly increased the bending strength. The bending fracture consists of three stages: first, tensile load induces the initiation of microcrack, and the crack propagates in an intergranular manner near the crack source; second, the crack propagates in a transgranular manner, and the fracture morphology exhibits quasi-cleavage; and finally, the fracture morphology changes to a ductile fracture in the substrate region. • An empirical model of the peak temperature at different depths was established. • An empirical model of the hardened depth was established. • Laser hardened layer increases the ability to resist the early bending deformation. • High brittleness of hardened layer and the larger tensile strain lead to the deterioration of bending property. [ABSTRACT FROM AUTHOR]

• The influences of laser parameters on the cleaning effect was discussed based on thermodynamics model. • The cleaned surface presented a significant higher surface free energy, which is benefit for improving the tensile shear strength and bending strength. • Tensile shear strength of the joint between CFRP and TC4 alloy depends on laser power density during laser cleaning process. Carbon fiber reinforced polymer (CFRP) has been regarded as an important candidate as structural components in structural engineering. With purpose of removing the epoxy resin and contaminants and in turn enhancing the bonding strength between CFRP and other materials, a nanosecond laser was used to remove the epoxy resin and contaminates on CFRP composites. A thermodynamics model was established to investigate the temperature field distribution, influences of laser power density and laser scanning speed on the cleaning effect, and therefore provide theoretical reference for cleaning experiments. The results showed that the laser power density of 8.8 kW.cm −2 and scanning speed of 1000 mm/s are preferred for an excellent cleaning effect. The cleaned surface presented a higher surface free energy, which in turn improved the tensile shear strength and bending strength. The failure mechanisms for the joints between TC4 and CFRP depend on laser power density for laser cleaning treatment. [ABSTRACT FROM AUTHOR]

Copyright of Jianzhu Cailiao Xuebao: Journal of Building Materials is the property of Journal of Building Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbon fibre reinforced carbon and copper (C/C-Cu) composites were prepared by a combination of chemical vapour infiltration and melt Cu alloy infiltration by pressure. Three kinds of C/C-Cu composites with different contents of pyrolytic carbon were prepared, and their bending properties were tested by Instron3369 electronic tensile testing machine. The results show that C/C-Cu composites have high bending strengths and show the characteristic of brittle fracture. The one with middle content of pyrolytic carbon has the highest bending strength, which attributes to coordination of carbon fibre, carbon matrix and Cu alloy. [ABSTRACT FROM AUTHOR]

The main content of the paper is to determine the optimal system parameters to measure bending property of fabric based on the Comprehensive Handle Evaluation System for Fabric and Yarn (CHES-FY). Four system parameters of the CHES-FY system were selected, including space distance between a pair of jaws, space distance between Bi-U-shaped pins, vertical distance between a pair of jaws and Bi-U-shaped pins, and diameter of Bi-U-shaped pins. In order to both determine the sequence of significant influences of the four system parameters on bending property, and to determine the optimal values of the four parameters to measure bending property of fabric, the Orthogonal design method was adopted to set the four system parameters as four factors and to assign four levels to each factor. Correlations were conducted between bending property and the featured indices (slope and peak value) from the pulling-out force and displacement curves recorded by the CHES-FY system. Comparing results show that the featured indices have good relations with both bending rigidity and bending length measured by FAST-2 meter as well as drape coefficient. Range values and average values are used to assess the significant relation of both factors and factor's levels with bending property of fabric. The sequence of significant influences of the four system parameters on bending property are diameter of Bi-U-shaped pins, space distance between Bi-U-shaped pins, vertical distance between a pair of jaws and Bi-U-shaped pins, and space distance between a pair of jaws. Moreover, the optimal parameters' levels are also obtained to better measure bending property of fabric. It indicates that the optimal system parameters of the CHES-FY system are a highly effective combination in evaluating bending property of fabric. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the influence of heat treatment on the mechanical properties of Ni-Ti file materials. Ni-Ti wire (1.00 mm ø) was processed into a conical shape with 0.30-mm diameter tip and 0.06 taper. Specimens were heated for 30 min at 300, 400, 450, 500 or 600°C. Non-heated specimens were used as controls. DSC, a cantilever-bending test and cyclic fatigue test were performed. Ms and Af for groups 400 and 450 were higher than those for others (p<0.05). The load/deflection ratios of groups 400, 450 and 500 were lower than that of group 600 (p<0.05). The bending load values at 2.0-mm deflection of groups 400, 450 and 500 were lower than those of group 300 and the control group (p<0.05). The NCFs of groups 400, 450 and 500 exceeded that of group 600(p<0.05). Changes in flexibility with heat treatment could improve the cyclic fatigue properties of Ni-Ti instruments. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the moisture-barrier performance was measured by an electrical calcium test before and after a repeated bending cycle of 10,000 times with various bending radii to investigate the bending properties of multilayer organic–inorganic barriers. We tested a single-layer barrier and three different multilayer-barrier structures. The measured change in barrier performance of the structures was correlated with calculated tensile strain. The calculation predicted the trend of the experimental data on the bending property, and the minimum bending radius seemed to be limited due to a sharp increase in the tensile strain at a bending radius less than 0.5cm. [Copyright &y& Elsevier]

Abstract: Butt joints of aluminum foam were made by three different brazing processes including brazing with multilayer filler metal in high vacuum of 10−3 (Pa) degree, brazing with multilayer filler metal in low vacuum of 1 (Pa) degree and brazing with monolayer filler metal in high vacuum of 10−3 (Pa) degree. The macrostructure and microstructure characteristics and bending strength of the joints were investigated and compared. The results indicate that the brazed specimen can achieve a satisfactory joint when brazed with multilayer filler metal in high vacuum. The bending strength of the joint is higher than that of the base metal. However, the bending strength of the joint is obviously lower than that of the base metal when brazed with multilayer filler metal in low vacuum, while it is slightly lower when brazed with monolayer filler metal in high vacuum. [Copyright &y& Elsevier]

Abstract: For the study of reinforced concrete beam stress performance under ultra-low temperature, based on the material constitutive and mechanism at ultra-low temperature, Using DIANA software environment, the numerical simulations is implemented, component test is expanded. The relationship is analysis between different temperatures. The results show that the reinforced concrete beam bearing capacity and stiffness are increased with lower temperature. [Copyright &y& Elsevier]

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Ebihara A, Yahata Y, Miyara K, Nakano K, Hayashi Y, Suda H. Heat treatment of nickel-titanium rotary endodontic instruments: effects on bending properties and shaping abilities. International Endodontic Journal, 44, 843-849, 2011. Abstract Aim To evaluate the bending properties and shaping abilities of nickel-titanium endodontic instruments processed by heat treatment. Methodology K3 files were heated for 30 min at 400 °C (group 400), 450 °C (group 450) and 500 °C (group 500). Files that were not heat treated served as controls. A cantilever-bending test was used to evaluate changes in specimen flexibility caused by heat treatment. Curved root canal models were prepared. The times required for preparation, deformation and fracture were recorded. Pre- and postoperative images were superimposed. The amounts of resin removed from both the inner and the outer sides of the curvature in the apical 6 mm were determined. Results In the cantilever-bending test, load values of the control group and group 500 were higher than those of groups 400 and 450 at the elastic range ( P < 0.05). At the superelastic range, the bending load of the control group was the highest amongst all groups ( P < 0.05). Regarding shaping ability, in the control group, root canals at the apex were transported more to the outer side of the curvature compared with those of all heat-treated groups ( P < 0.05). Root canals of group 400 at 3 mm from the apex were transported less compared with those of other groups ( P < 0.05). No significant difference was found in working time amongst the groups. In group 450, there was no plastic deformation or fracture of the file. Conclusions Heat treatment of files might improve their flexibility, making them more effective for preparation of curved canals. [ABSTRACT FROM AUTHOR]

Down fibers have superior thermal insulating properties as natural nonwoven and filler materials. Physical properties include single-fiber bending, down assembly bulkiness, compressibility and recoverability, which all affect down fibers' thermal insulation greatly. Research on the physical properties of down fibers has been very limited. In this paper, the physical property tests and analyses on both single down fibers and down fiber assemblies were carried out seriatim. The fiber bending properties were tested by an axial-buckling method, and the assembly compressibility and recoverability were tested by fiber assembly conductivity analyzer. The behavior mechanisms were explained by fiber structure and arrangement factors. Synchronously, the physical properties of down are evaluated and compared with other kinds of keratin fibers and wool. [ABSTRACT FROM AUTHOR]

Aim To investigate the effect of heat treatment on the bending properties of nickel–titanium endodontic instruments in relation to their transformation behaviour. Methodology Nickel–titanium super-elastic alloy wire (1.00 mm Ø) was processed into a conical shape with a 0.30 mm diameter tip and 0.06 taper. The heat treatment temperature was set at 440 or 500 °C for a period of 10 or 30 min. Nonheat-treated specimens were used as controls. The phase transformation behaviour was examined using differential scanning calorimetry. A cantilever-bending test was used to evaluate the bending properties of the specimens. Data were analyed byanova and the Tukey–Kramer test ( P = 0.05). Results The transformation temperature was higher for each heat treatment condition compared with the control. Two clear thermal peaks were observed for the heat treatment at 440 °C. The specimen heated at 440 °C for 30 min exhibited the highest temperatures for Ms and Af, with subsequently lower temperatures observed for specimens heated at 440 °C for 10 min, 500 °C for 30 min, 500 °C for 10 min, and control specimens. The sample heated at 440 °C for 30 min had the lowest bending load values ( P < 0.05), both in the elastic range (0.5 mm deflection) and in the super-elastic range (2.0 mm deflection). The influence of heat treatment time was less than that of heat treatment temperature. Conclusions Change in the transformation behaviour by heat treatment may be effective in increasing the flexibility of nickel–titanium endodontic instruments. [ABSTRACT FROM AUTHOR]

• The types of interfacial IMCs kept unchanged with laser power. • The morphology of IMCs layer turned into sandwich-like structure in high laser power. • The fracture load firstly increased and then reached a plateau with increasing laser power. • The relationship between the interfacial temperature and IMCs layer was discussed via finite element numerical simulation. Laser welding-brazing technique was used for lap joining of Q235 steel to AA5052 aluminum alloy using a flux-cored Zn-22Al filler wire. The influence of heat input on microstructure, joint strength and bending property of laser Al/steel joints was investigated. The results showed that the types of interfacial intermetallic compounds (IMCs) were kept unchanged with the different laser powers, i.e., Fe 2 Al 5-x Zn x phase and FeZn 10 ; while the thickness and morphology of IMC layer changed significantly. This was mainly ascribed to the large increase of the interfacial temperature with the rising laser power, which led to an intensified diffusion reaction. The fracture load first increased and then reached a plateau with the increasing laser power. However, the laser power had very limited influence on the joint bending property because of the formation of dispersed tough FeZn 10. Numerical simulation indicated that the interfacial temperature along the interfacial region varied, decreasing from the weld root to weld toe. The peak temperature increased by 700 ℃ and liquid–solid reaction time increased 3.41 s with the increased laser power, which was responsible for the change of IMCs layer. [ABSTRACT FROM AUTHOR]

In order to understand the relationship between the internal defects of yarn structures and the mechanical properties of yarn, we developed a yarn model which consists of mass and three types of springs for expression and construction, and bending. The yarn model can express the Euler buckling phenomenon depending on its bending stiffness. Using the yarn model, the tension relaxation simulations of the yarn package structures were performed, and it was found that our yarn model has a suffcient ability to express the influence of the bending property of yarn on the internal defects like the circular buckling of the yarn package structures. [ABSTRACT FROM AUTHOR]

It is estimated that about tow million tons of used fiber are discharged annually in Japan. This situation has raised the concerns about the necessity to find innovative usage of used fibers and new recycling technologies. Therefore, various attempts have been carried out in our textile industry to construct the recycling-type society. For example, compression molding system of lumber substitutive materials by using the fiber wastes as raw material is very interesting. In this molding process, the binder material such as thermoplastic fiber is used in order to bind the neighboring fiber wastes. It can be easily expected that the shape of melted binder remarkably affects on the mechanical properties of substitute lumber. In this paper, the felt is pre-molded in which PP fibers with various sizes are added as a binding material. Then the felt turns to fiber board by the compression molding method under heating. The effects of binder shape to the bending properties of the fiber board are discussed. As a result, it is clarified that the fiber sizes of PP binder remarkably affects on the shape of melted PP and also the bending properties of molded board. [ABSTRACT FROM AUTHOR]