摘要
粘弹性是复合材料最重要的力学性能之一。基于Ｂｏｌｔｓｍａｎ迭加原理和Ｓｃｈａｐｅｒｙ非线性粘弹性理论，本文提出了一变量分离式粘弹性本构关系，且由Ｋａｃｈａｎｏｖ“连续性”概念，将损伤变量引入本构关系式中，按不同的加载速度和加载方向对正交玻璃布－环氧材料进行了加、卸载实验研究。根据Ｌｅｍａｉｔｒｅ和Ｃｈａｂｏｃｈｅ由宏观弹性常数变化确定损伤量的方法，测得材料的损伤并用一二次函数表示。通过对实验数据的一系列处理方法，确定了材料常数，验证了本文理论的有效性。实验表明，当纤维做为主要承力者时，无粘性产生，材料的损伤和总应变相关而与应变率无关，并得到强度值随应变率增加而升高，极限应变不随应变率变化的结论。
Viscidity is one of the most important mechanical behaviors in composite material. Based on theBoltsmen's superposition and Schapery's nonlinear viscoelastic theory, the paper put forward a separating variable viscoelastic constitutive relation. From Kachanov's'continuum' concept, the damage islead to the constitutive equation. The experiment is conducted on close plied glass fiber cloth/epoxycomposite with different loading and unloading speeds and directions. The damage value of the composite is measured and represented by a curve with two orders of power according to Lemaitre's andChaboch's method that damage is related to the variation of macro-elastic modulus. Through a seriesof works on experiment data, the material coefficient is determined. The validity of the theory is verified. The experimental results show that if the loads are born by the fibers in orthogonal stress-strainrelationship is linear elastic. Damage of the composite depends on the shearing strain but does not haveany relation with shearing strain rate. We also have got the results that the shearing strength increased with rise of strain rate and the ultimate strain is unaffected by strain rate.
出处
《应用力学学报》
CAS
CSCD
北大核心
1996年第1期53-58,共6页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金
关键词
玻璃布-环氧
粘弹性
损伤
本构关系
复合材料
cross-plied glass fiber cloth/epoxy cemposite, viscoelasticity, damage, constitutive relation.
