In this paper,the failure features of strip tensile specimen were observed and analysed for need-le-punched non-woven geotextiles.A mechanical model which expresses the relation between thetensile modulus,the strip sp...In this paper,the failure features of strip tensile specimen were observed and analysed for need-le-punched non-woven geotextiles.A mechanical model which expresses the relation between thetensile modulus,the strip specimen size,contraction factor and the tensile strength of non-wovenfabric was derived.The theoretical prediction showed that the main factor influencing tensilestrength of non-woven geotextile specimens with different size is the contraction factor of specimenor the specimen aspect ratio(width/length).The larger the aspect ratio,the higher the tensilestrength test value of geotextiles,but the experiments showed that the specimen tensile strength isnot increased with increasing the width of specimen.The reason was discussed and it seemed thatthe deviation could be served as an indication of the degree of imperfectness of the non-wovenstructure.展开更多
In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester res...In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester resin where styrene monomer used as a solvent and 1% methyl ethyl ketone peroxide (MEKP) was used as initiator. Two bar pressure was applied for complete wetting of the fabric by a Padder and curing was done at 130?C for 10 minutes. The physico-mechanical characteristics of untreated and treated samples were examined and evaluated. It was revealed that moisture content (MC) and water absorbency of the treated specimens were decreased with the increase of resin percentage (%) in the fabrics. MC and water absorbency were maximum decreased up to 50.23% and 60.14% respectively by 25% resin treatment. On the other hand, bending length (BL), flexural rigidity (FR), flexural modulus (FM) and tensile strength (TS) were enhanced with the increase of resin percentage in the fabrics which resulted higher fabric stiffness. The maximum improvement of BL, FR, FM and TS were found to be 6.67%, 56.04%, 10.57% and 18.75% respectively in comparison to untreated sample. Soil degradation tests exhibited that 33.59% TS loss occurred for untreated specimens where only 8.04% loss of TS found for 25% resin treated one. Furthermore, jute based twill, zigzag and diamond fabrics were also treated by 10%, 15%, 20% and 25% resin, then measured their TS and compared with plain fabrics. It was revealed that plain fabrics have superior TS over other fabrics. It was also evident that TS enhanced for all the fabrics after resin treatment and maximum increase found for all the fabrics up to 25% resin treatment.展开更多
有纺土工织物反滤应用常处于双向受拉状态。孔径特征是有纺织物反滤设计的重要参数。由于双向拉应变引起孔径的变化显著,导致原本满足孔径指标的有纺织物时常反滤失效。根据有纺织物的微观结构及受力特点,分析双向拉应变导致条膜及孔径...有纺土工织物反滤应用常处于双向受拉状态。孔径特征是有纺织物反滤设计的重要参数。由于双向拉应变引起孔径的变化显著,导致原本满足孔径指标的有纺织物时常反滤失效。根据有纺织物的微观结构及受力特点,分析双向拉应变导致条膜及孔径变化的机理,建立有纺织物单孔结构模型,推导孔径特征参数随双向拉应变变化的理论解,包括开孔面积率(POA,percent open area)及理论孔径(Obi)等。以等轴双向拉伸为例验证理论解。采用数字图像法在拉伸试验进行的同时,测试各级拉应变下3种单丝条膜有纺织物的孔径参数,包括开孔面积率、孔径分布曲线、等效孔径(O95),分析各项孔径参数随拉双向应变的变化规律,并与理论解的预测结果进行对比。通过试验结果可见,理论解较好地预测了开孔面积率(POA)及等效孔径(O95)随双向拉应变的增大趋势,对变化斜率及数值的预测较准确,并得出孔径参数与等轴双向拉应变的近似线性关系,为反滤设计中预测孔径特征变化提供了理论依据。展开更多
文摘In this paper,the failure features of strip tensile specimen were observed and analysed for need-le-punched non-woven geotextiles.A mechanical model which expresses the relation between thetensile modulus,the strip specimen size,contraction factor and the tensile strength of non-wovenfabric was derived.The theoretical prediction showed that the main factor influencing tensilestrength of non-woven geotextile specimens with different size is the contraction factor of specimenor the specimen aspect ratio(width/length).The larger the aspect ratio,the higher the tensilestrength test value of geotextiles,but the experiments showed that the specimen tensile strength isnot increased with increasing the width of specimen.The reason was discussed and it seemed thatthe deviation could be served as an indication of the degree of imperfectness of the non-wovenstructure.
文摘In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester resin where styrene monomer used as a solvent and 1% methyl ethyl ketone peroxide (MEKP) was used as initiator. Two bar pressure was applied for complete wetting of the fabric by a Padder and curing was done at 130?C for 10 minutes. The physico-mechanical characteristics of untreated and treated samples were examined and evaluated. It was revealed that moisture content (MC) and water absorbency of the treated specimens were decreased with the increase of resin percentage (%) in the fabrics. MC and water absorbency were maximum decreased up to 50.23% and 60.14% respectively by 25% resin treatment. On the other hand, bending length (BL), flexural rigidity (FR), flexural modulus (FM) and tensile strength (TS) were enhanced with the increase of resin percentage in the fabrics which resulted higher fabric stiffness. The maximum improvement of BL, FR, FM and TS were found to be 6.67%, 56.04%, 10.57% and 18.75% respectively in comparison to untreated sample. Soil degradation tests exhibited that 33.59% TS loss occurred for untreated specimens where only 8.04% loss of TS found for 25% resin treated one. Furthermore, jute based twill, zigzag and diamond fabrics were also treated by 10%, 15%, 20% and 25% resin, then measured their TS and compared with plain fabrics. It was revealed that plain fabrics have superior TS over other fabrics. It was also evident that TS enhanced for all the fabrics after resin treatment and maximum increase found for all the fabrics up to 25% resin treatment.
文摘有纺土工织物反滤应用常处于双向受拉状态。孔径特征是有纺织物反滤设计的重要参数。由于双向拉应变引起孔径的变化显著,导致原本满足孔径指标的有纺织物时常反滤失效。根据有纺织物的微观结构及受力特点,分析双向拉应变导致条膜及孔径变化的机理,建立有纺织物单孔结构模型,推导孔径特征参数随双向拉应变变化的理论解,包括开孔面积率(POA,percent open area)及理论孔径(Obi)等。以等轴双向拉伸为例验证理论解。采用数字图像法在拉伸试验进行的同时,测试各级拉应变下3种单丝条膜有纺织物的孔径参数,包括开孔面积率、孔径分布曲线、等效孔径(O95),分析各项孔径参数随拉双向应变的变化规律,并与理论解的预测结果进行对比。通过试验结果可见,理论解较好地预测了开孔面积率(POA)及等效孔径(O95)随双向拉应变的增大趋势,对变化斜率及数值的预测较准确,并得出孔径参数与等轴双向拉应变的近似线性关系,为反滤设计中预测孔径特征变化提供了理论依据。
