摘要
研究了含孔天然苎麻纤维织物/异氰酸酯复合板在双轴向拉伸载荷下的力学行为。对0.5、1.0、2.0、4.0 mm 4种孔径板进行了单向和双轴向载荷拉伸试验,同时采用数字散斑相关方法对全场位移及孔径大小对应变的影响进行了表征。结果表明:当载荷线性变化时孔周围的位移场分布较为均匀;随着载荷接近破坏值,位移场呈非线性分布并出现高应变值点,破坏以极快的速度沿孔边在这些点首先发生。随着孔径的增大,在1000～2000 N双轴向载荷下孔周围相同面积内x、y方向正应变的平均值减小,应变值波动小但范围增大。材料在单向和双轴向拉伸时表现出不同的力学特征:双轴向载荷下失效强度要比单向拉伸时低,降低比例为14%～27%,且随着孔径的增加而增加。
The mechanical behavior of natural ramie / isocyanate laminate composite with holes was investigated by the biaxial tensile method. The uniaxial and biaxial load tensile tests for four kinds of 0. 5, 1. 0, 2.0, 4.0 mm aperture were conducted, and the effects of displacement and the pore size on strain were characterized by the digital speckle correlation method. The result shows that the displacement field around the hole is uniform distribution when the toad changes linearly, however, while the load is closing to failure, non-linear distribution and high strain points appear, which are broken first quickly. As the radius of the pore increases, average strains in x and y directions are reduced within the same area around the hole under 1000-2000 N biaxial load and fluctuation of strain decreases slightly. Mechanical characteristics of materials are different under different tensile ways, strength under biaxial load is lower than the one under uniaxial tension and the reduction ratio, which increases with the size of pore radius raising, is about 14%-27% of the uniaxial load.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2010年第4期195-199,共5页
Acta Materiae Compositae Sinica
基金
国家"十一五"支撑项目(2006BAD19B07
2008BADA9B0201)
关键词
双轴向拉伸
含孔复合材料
数字散斑相关方法
应变
in-plane biaxial tensile test
composite with holes
digital spackle correlation method
strain
