摘要
以往建筑结构的阻尼通常从宏观上把握,阻尼矩阵以Rayleigh阻尼的不同拓展形式为主,其物理意义并不明确。依据混凝土材料的Kelvin粘弹性阻尼模型,经结构动力学分析,推导建立了弹性阶段剪切型钢筋混凝土框架结构阻尼矩阵与混凝土材料粘滞系数之间的关系,并给出了比例阻尼矩阵的判别准则。然后利用纤维增强混凝土的阻尼测试结果进行了算例分析,给出了10层复合纤维增强阻尼钢筋混凝土框架结构阻尼矩阵的具体表达式和一阶模态阻尼比,结果表明此结构阻尼矩阵不仅可像结构质量、结构刚度一样定量把握,且其物理意义明确;相比于普通混凝土框架,各复合纤维增强阻尼混凝土框架的一阶模态阻尼比有了较大的提高,其主要原因在于纤维的掺入增加了纤维与水泥基材的界面摩擦力,而乳胶的阻尼增强机理在于聚合物分子在外力作用下的内耗增加了普通混凝土的阻尼能力。
In tradition,the damping for structural dynamic analysis was simply considered as Rayleigh damping or its different development forms without obvious physical meaning.Here,concrete materials were considered as a viscoelastic material described by Kelvin model,the relationship between viscous coefficient of concrete materials and damping matrix of a shear-type reinforced concrete (RC) frame within elastic stage was derived with dynamic analysis,and a judgment criterion of the proportional damping matrix was obtained.Then,the expression of the damping matrix and the 1st modal damping ratio of a 10-floor RC frame structure with fibers were given on the basis of the damping experimental results of fiber-reinforced concrete materials.It was found that the damping matrix can be represented quantitatively,similar to the structural mass and stiffness,possessing an obvious physical meaning;compared with an ordinary reinforced concrete frame,the fiber-reinforced concrete frame structure has a larger 1st modal damping ratio;the damping reinforcement of RC frames with latex powder or fibers lies in the polymer molecules' dissipating energy ability and interfaces' friction of fibers and cement hydration products.
出处
《振动与冲击》
EI
CSCD
北大核心
2010年第7期169-173,共5页
Journal of Vibration and Shock
基金
国家自然科学基金面上项目(50878070)
08年深圳市科技计划公共科技项目(SY200806260024A)
关键词
混凝土粘滞系数
框架结构阻尼矩阵
比例阻尼
一阶模态阻尼比
阻尼增强机理
viscosity coefficient of materials
damping matrix of a structure
proportional damping
the 1st modal damping ratio
damping reinforcement mechanism
