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
General surgery hernia is a common and frequently- occurring disease in the world. In the tension-free hernia repair surgery, polypropylene (PP) patch has been confirmed as the most popular surgical implants. In thi...General surgery hernia is a common and frequently- occurring disease in the world. In the tension-free hernia repair surgery, polypropylene (PP) patch has been confirmed as the most popular surgical implants. In this study, domestic medical PP monofilament was selected as raw material whose diameter was 0.15 mm, and the patch was knitted in the warp knitting machine of 12E gauge with one bar. Using the method of orthogonal experiment with three factors and three levels, the best heat-setting process of PP mesh was determined at the temperature of 130 ~C with 10 min under tension-free conditions. The relationship between heat-setting tension and performance of the patch was discussed. Patches with different porosity were prepared, and then structural parameters including density, thickness, porosity, and mechanical properties including tensile breaking strength, bursting strength, tearing strength, flexural rigidity and suture pulling out strength were tested and compared. The experimental results show that: the smaller of the patch's density, the higher of the porosity; other properties including density, thickness, bending stiffness, tensile breaking strength, bursting strength, tear strength, and suture pulling out strength reduce in varying degrees. This different degree of reduction is worth summarizing.展开更多
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General surgery hernia is a common and frequently- occurring disease in the world. In the tension-free hernia repair surgery, polypropylene (PP) patch has been confirmed as the most popular surgical implants. In this study, domestic medical PP monofilament was selected as raw material whose diameter was 0.15 mm, and the patch was knitted in the warp knitting machine of 12E gauge with one bar. Using the method of orthogonal experiment with three factors and three levels, the best heat-setting process of PP mesh was determined at the temperature of 130 ~C with 10 min under tension-free conditions. The relationship between heat-setting tension and performance of the patch was discussed. Patches with different porosity were prepared, and then structural parameters including density, thickness, porosity, and mechanical properties including tensile breaking strength, bursting strength, tearing strength, flexural rigidity and suture pulling out strength were tested and compared. The experimental results show that: the smaller of the patch's density, the higher of the porosity; other properties including density, thickness, bending stiffness, tensile breaking strength, bursting strength, tear strength, and suture pulling out strength reduce in varying degrees. This different degree of reduction is worth summarizing.