Currently,polypropylene( PP) synthetic mesh is a kind of common material used for pelvic floor's repairing and reconstruction.The repairing mesh is generally made with different hole shape and size.Porosity is one...Currently,polypropylene( PP) synthetic mesh is a kind of common material used for pelvic floor's repairing and reconstruction.The repairing mesh is generally made with different hole shape and size.Porosity is one of the most important indicators of PP mesh.Two different-structure PP meshes are selected through adopting corresponding target density in the heat setting process for meshes owning different porosity.Then performance and structure of two kinds meshes with different porosity are tested.The results showed that: the increase of porosity leaded to the decreases of meshes' thickness,tensile strength and bursting strength.Meshes' bending stiffness was reduced and they became softer,but there was no significant change in suture pulling-out force, which maybe associated with the large aperture of PP meshes.展开更多
Three different kinds of notch involving single edge notch （ SEN）, double edge notch （ DEN ） and central notch （ CEN ） were preset in flexible warp knitting metal mesh, and the tensile properties of notch sample...Three different kinds of notch involving single edge notch （ SEN）, double edge notch （ DEN ） and central notch （ CEN ） were preset in flexible warp knitting metal mesh, and the tensile properties of notch samples were tested. Three kinds of notch samples＇ sensitivity were investigated through different notch lengths. Then failure process and tensile properties were contrasted and analyzed between intact and notch samples. Experiment and analysis results showed that positive Poisson＇s ratio effect gave rise to obvious waist binding and special inverted triangle loading area. All samples were sensitive to three kinds of notches. And notch sensitivity was closely related to notch form and notch length. The notch procession obviously deteriorated the mechanical properties of flexible warp knitting metal mesh. Sample with different notch lengths and breakage locations determined different tensile strengths that sample could bear. The fitting function of waist binding track satisfied the parabolic equation.展开更多
The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballastlayer, has served as motivation to develop the advanced measurement of thermal cycles in this laye...The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballastlayer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the averageseasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weathersituation, Barber＇s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessmentof improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber （particlesize 0.2-4 mm） by weight of the total mix, as sub-ballast layer in railway and base layers on roads, recurring to the Superpave mixdesign compaction enhanced after computer simulations to evaluate real stresses derived from the rail traffic and climatic conditions.This article following the assessment of the average seasonal temperatures, involves the characterization of rubberized materials withattention to crumb rubber properties, designed with dry technology, to enhance the bitumen-rubber and binder-voids ratios. Indirecttensile strength and water sensitivity tests were applied for the evaluation of its mechanical properties including dynamic complexmodulus at elevated temperature to measure the amount of bitumen absorbed by the rubber. The rubberized mix-results obtained andthe comparison with a conventional HMA （hot mix asphalt） show that these dry rubber bituminous mixtures are particularly effective indamping vibrations. The purpose of using rubber modifiers in hot mix asphalt to obtain a stiffer-elastic sustainable material has beenachieved for the assessment of its behavior in sub-ballast/base layers.展开更多
文摘Currently,polypropylene( PP) synthetic mesh is a kind of common material used for pelvic floor's repairing and reconstruction.The repairing mesh is generally made with different hole shape and size.Porosity is one of the most important indicators of PP mesh.Two different-structure PP meshes are selected through adopting corresponding target density in the heat setting process for meshes owning different porosity.Then performance and structure of two kinds meshes with different porosity are tested.The results showed that: the increase of porosity leaded to the decreases of meshes' thickness,tensile strength and bursting strength.Meshes' bending stiffness was reduced and they became softer,but there was no significant change in suture pulling-out force, which maybe associated with the large aperture of PP meshes.
基金Shanghai Excellent Academic Leaders Project of Shanghai Municipal Science and Technology Commission,China，the Fundamental Research Funds for the Central Universities,Chna，the Research Fund for Young Teachers of Donghua University,China，the Innovation Fund Supports Projects of Postgraduate's Thesis of Donghua University,China
文摘Three different kinds of notch involving single edge notch （ SEN）, double edge notch （ DEN ） and central notch （ CEN ） were preset in flexible warp knitting metal mesh, and the tensile properties of notch samples were tested. Three kinds of notch samples＇ sensitivity were investigated through different notch lengths. Then failure process and tensile properties were contrasted and analyzed between intact and notch samples. Experiment and analysis results showed that positive Poisson＇s ratio effect gave rise to obvious waist binding and special inverted triangle loading area. All samples were sensitive to three kinds of notches. And notch sensitivity was closely related to notch form and notch length. The notch procession obviously deteriorated the mechanical properties of flexible warp knitting metal mesh. Sample with different notch lengths and breakage locations determined different tensile strengths that sample could bear. The fitting function of waist binding track satisfied the parabolic equation.
文摘The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballastlayer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the averageseasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weathersituation, Barber＇s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessmentof improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber （particlesize 0.2-4 mm） by weight of the total mix, as sub-ballast layer in railway and base layers on roads, recurring to the Superpave mixdesign compaction enhanced after computer simulations to evaluate real stresses derived from the rail traffic and climatic conditions.This article following the assessment of the average seasonal temperatures, involves the characterization of rubberized materials withattention to crumb rubber properties, designed with dry technology, to enhance the bitumen-rubber and binder-voids ratios. Indirecttensile strength and water sensitivity tests were applied for the evaluation of its mechanical properties including dynamic complexmodulus at elevated temperature to measure the amount of bitumen absorbed by the rubber. The rubberized mix-results obtained andthe comparison with a conventional HMA （hot mix asphalt） show that these dry rubber bituminous mixtures are particularly effective indamping vibrations. The purpose of using rubber modifiers in hot mix asphalt to obtain a stiffer-elastic sustainable material has beenachieved for the assessment of its behavior in sub-ballast/base layers.
