摘要
目前PVC土工膜双向拉伸力学特性试验研究主要采用普通十字型试样,其四肢为矩形,夹角处采用圆弧过渡,试样破坏时,中心区域可测得的最大真应变约为30%,远小于PVC土工膜在双向拉伸条件下能够达到的最大应变。为了获得更加完整的PVC土工膜双向拉伸应力–应变曲线,在原普通十字型双向拉伸试样的基础上,通过数值分析和试验验证相结合的方法对试样形状及尺寸进行了进一步优化,确定了加固哑铃型试样型式,并通过细部优化得到了该试样的具体尺寸参数;试验验证表明,该试样具有应力传递效果好、应力集中程度低、中心区(薄圆)应力值大且分布均匀的特点,试样破坏时测得中心区最大真应变达到100.4%,能够满足PVC土工膜双向拉伸力学特性试验研究的要求。
The most common PVC geomembrane specimen used in biaxial tensile tests is a traditional cruciform one characterized by four rectangular clamp arms, intersection of which is connected by a corner fillet. Based on the traditional cruciform specimen, the maximum measured true strain in the central area can only reach 30%, which is far less than the prospective strain level under biaxial tension loads for PVC geomembrane. In order to get a more complete stress-strain curve of this material, a reinforced dumbbell-shaped specimen is designed on the basis of the traditional specimen by means of a coupled method of numerical simulation and experiment verification. The results of verification tests show that this new specimen presents high and evenly-distributed stress and low degree of stress concentration in biaxial tension states. The maximum true strain obtained at failure time can reach 100.4%, indicating that the reinforced dumbbell-shaped specimen can meet the demands of mechanical property research of PVC geomembrane under biaxial tension states.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2016年第S1期62-68,共7页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51079047
51379069
51409083)
江苏高校优势学科建设工程项目(PAPD)
关键词
PVC土工膜
双向拉伸试验
力学特性
应力–应变关系
试样优化
PVC geomembrane
biaxial tensile test
mechanical property
stress-strain relationship
specimen optimization
