单边切口薄板研究聚乙烯醇纤维增强水泥基复合材料断裂韧性  

FRACTURE TOUGHNESS INVESTIGATION OF POLYVINYL ALCOHOL REINFORCED CEMENT COMPOSITES BY SINGLE-NOTCHED THIN SHEET

作　　者：高淑玲[1] 徐世烺[1] 

机构地区：[1]大连理工大学土木水利学院海岸与近海工程国家重点实验室

出　　处：《工程力学》2007年第11期12-18,共7页Engineering Mechanics

基　　金：国家自然科学基金重点项目(50438010)

摘　　要：利用单边切口薄板对配制的聚乙烯醇纤维增强水泥基复合材料进行单轴直接拉伸试验研究,得到硬化的荷载-裂缝张开位移全曲线。通过试验观察到缺口尖端处出现呈发散状的多条微小裂纹,部分试件在远离切口处还有多条裂缝出现,并不像混凝土或水泥净浆这类半脆性、脆性材料只有单条裂缝并沿着单条路径开裂,因此,适用于应变软化材料的双K断裂理论以及断裂能理论不能直接用在应变已经发生假硬化的材料中。鉴于上述原因,该文提出起裂断裂韧度和耗散能两个韧性评价指标。The hardening load-crack mouth opening displacement curves in uniaxial direct tension are obtained for the single-notched thin sheet made ofpolyvinyl alcohol reinforced cementitious composites. Besides, multiple radiate microcracks arises along the notch tip and some subparallel cracks appear along the whole specimen apart from the notch tip, while some brittle and quasi-brittle composites such as cement paste and concrete split along only one path. So the fracture mechanism of polyvinyl alcohol ＇reinforced cementitious composites is very different from some strain softening composites whose fracture toughness can be evaluated by double-K fracture criterion and fracture energy. Therefore, two toughness evaluation norm of initial fracture toughness and dissipation energy are discussed for polyvinyl alcohol reinforced cementitious composites.

关 键 词：PVA纤维增强水泥基复合材料 假应变硬化 直接拉伸 多缝开裂 砂浆起裂断裂韧度 复合起裂断裂韧度 

分 类 号：TU528[建筑科学—建筑技术科学] O346.12[理学—固体力学]