【作者】 商欣萍；

【导师】 储才元；

【作者基本信息】 东华大学 ， 纺织材料与纺织品设计， 2004， 博士

【摘要】 本论文结合土工织物的实际应用，从试验和理论两个方面针对试样宽度对土工织物拉伸性能的影响及开孔土工织物孔截面上的应力分布情况进行了分析研究，研究结果为土工织物抗拉强度的测试和实际工程应用提供了理论依据和参考。 通过对土工织物不同宽度的拉伸试验，分析了土工织物试样宽度与断裂强度、断裂伸长率、侧向收缩率、定伸长强度、弹性模量之间的关系。结果表明：土工织物的断裂强度与试样宽度之间存在着幂函数关系，侧向收缩是影响不同宽度试样断裂强度的潜在因素；试样宽度对土工织物断裂伸长率没有明显的影响；伸长率较大时的定伸长强度同样会受试样宽度的影响；土工织物的弹性模量随试样宽度的增大略有增加。 将边界元法应用到土工织物拉伸力学性能的研究中，编写了针对计算研究土工织物拉伸力学性能的边界元法程序。 用边界元法程序从理论上计算分析了土工织物试样宽度与拉伸断裂强度间的关系，理论计算结果与试验结果具有相同的趋势，证实了土工织物的断裂强度与试样宽度之间存在着幂函数关系。同时从理论上计算了土工织物试样单向拉伸时试样内的应力分布情况，计算结果表明：夹头夹持试样边附近的拉应力集中现象较明显，试样在靠近夹头附近不受约束的自由边处则存在显著的剪应力集中。 用边界元法程序分别对开有圆孔或椭圆孔或方孔的土工织物试样在单向与双向拉伸时孔截面上的应力分布情况进行了计算与分析，结果表明：土工织物孔截面上的应力集中出现在距孔边3倍左右的孔径尺寸范围内；孔边附近应力集中的程度与孔的形状、大小、位置及试样的尺寸有关。不同形状孔附近的应力集中程度还与土工织物试样的拉伸条件有关，试样单向拉伸或双向拉伸时，孔边的最大应力值不同，最大应力所出现的位置也不同。 为验证用边界元法计算开孔土工织物应力分布的正确性，对开有不同大小圆孔或方孔的土工织物试样进行了拉伸试验。将开孔试样的理论计算断裂强度与试验所得结果进行分析对比，理论值与试验值具有相同的变化趋势，理论值较试验值偏低；通过记录开孔试样的拉伸过程，证实了土工织物孔边附近存在着应力集中现象；并根据计算结果提出了开孔土工织物安全应用的方法。更多还原

【Abstract】 Tensile properties are very important for application of geotextiles. In order to provide theoretical bases and references for practical application, the influence of the specimen width to geotextile’s tensile properties and the stress distribution of the holed geotextile were investigated on both experiment and theoretic in this thesis.Based on tensile testing for different width specimens of geotextiles, the relationship between specimen width and breaking strength, breaking elongation, lateral contraction, strength of fixed elongation and elasticity modulus were analyzed. The results show that there is power function between breaking strength and specimen width of geotextile affected by lateral contraction, and the specimen width has no evident effect on geotextile’s breaking elongation, but has effect on the strength of fixed elongation when the fixed elongation is larger. The elasticity modulus of geotextile increases a little with increasing of the specimen width.Boundary element method was used to analyze tensile properties of geotextiles. The calculation program of boundary element method for geotextiles was compiled.The relationship between geotextile specimen width and breaking strength was calculated and analyzed with boundary element method program. The results of theoretic and experiment have same regularity. It validates that there is power function between breaking strength and specimen width of geotextile. The stress distribution in the specimen under uniaxial tension was also calculated. The results indicate that there is tensile stress concentration near two sides of the specimen gripped by the clamps, at the same time there is prominent shearing stress concentration on area of the free sides of the specimen near the clamps.The stress distribution on the cross section of geotextile with a circle or an ellipse or a square hole under uniaxial tension or double-axial tension was calculated with boundary element method program. The results show that the stress concentration appear at the range from the hole side to about 3 times of the hole diameter, and the degree of stress concentration near the hole is related to the shape of the hole, the size of the hole, the position of the hole and the dimension of the specimen. The stressconcentration near the hole of different shape is also related to the tensile condition. When the specimen bears uniaxial tension or double-axial tension, the value of the maximum stress near the hole side is different and the position of the maximum stress is also different.The tensile testing of geotextile specimen with a circle hole or a square hole was carried out in order to testify the results of boundary element method. Comparing the theoretical breaking strength with the experimental breaking strength of the holed geotextile specimen, they change as uniform trend though the theoretical results are lower than the experimental results. It was proved that there is stress concentration near the hole on holed geotextile by recording the tensile process of the holed geotextile specimen. The method of reasonable application of holed geotextiles has also been put forward.更多还原