乙烯基酯树脂浇铸体的高应变率压缩响应行为  

Effect of strain rate on the compression behavior of vinyl ester resin casting

作　　者：熊涛[1] 杨斌[1] 熊杰[1] 徐新建[1] 周凯[1] 毛明忠[1] 

机构地区：[1]浙江理工大学先进纺织材料与制备技术教育部重点实验室,杭州310018

出　　处：《复合材料学报》2006年第6期46-51,共6页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金项目(10372092)

摘　　要：利用电子万能试验机和分离式Hopkinson压杆研究了乙烯基酯树脂浇铸体在准静态和高应变率下的压缩特性,考察了试样压缩失稳和破坏的形貌。结果表明:在准静态加载下(应变率为3.3×10-4/s^6.6×10-3/s),材料呈韧性破坏,失稳应力、失稳应变能密度均随应变率的提高而提高,失稳应变随应变率的提高而降低;在高应变率下(应变率为950/s^5800/s),材料呈脆性破坏,失稳应力、失稳应变能密度均随应变率的提高呈增加趋势,而失稳应变也随应变率的提高而提高,这与准静态不同,表明在高应变率下,材料发生了“强迫高弹形变”。观察试样失稳和破坏后的形貌可以发现,试样的破坏在失稳前正应力起主导作用,失稳后切应力起主导作用,使试样产生裂纹进而造成宏观破坏;乙烯基酯树脂内部损伤的演化,也依赖于应变和应变率。Quasi-static and high strain rate compressive experiments on the vinyl ester resin casting were carried out by using a material universal testing machine and Hopkinson bar, and the behaviors of compressive instability and fracture of the resin casting at different strain rates were investigated. The results indicate that the response behavior of the resin casting is controlled by different mechanisms at different strain rates and some mechanical properties of vinyl ester casting are rate- dependent., the castings are destroyed in a toughness mode at strain rate 3.3 × 10^-4/s-6.6×10^-3/s, while the castings are destroyed in a brittleness mode at strain rate 950/s-5800/s. The yield stress, yield strain energy density are all increased with the increasing of strain rates under quasi-static loading as well as under high strain rates loading. What is interesting is that the yield strain is decreased with the strain rate increasing under quasi-static loadings while it is increased under high strain rate loadings. It is considered that in the casting there occurred forced high elastic deformation at high strain rates. The damage of the specimens is mainly controlled by axial stress before unstable deformation, while mainly controlled by shear stress after unstable deformation, and then all fracture finally. The development of the cracks inside the castings is also rate-dependent.

关 键 词：乙烯基酯树脂 准静态 高应变率 应变率响应 裂纹扩展 

分 类 号：TB332[一般工业技术—材料科学与工程]