阻尼作用及产生机理阻尼材料与阻尼结构

噪声与振动控制技术,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,西北工业大学精品课程专业核心课程,振动与噪声控制技术,本讲内容,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,阻尼作用及产生机理阻尼材料与阻尼结构,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,阻尼作用及产生机理,弹性结构内阻尼的定义,阻尼的作用,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,阻尼产生机理,1，工程材料内阻尼2，流体的粘滞阻尼3，结合面阻尼与库仑摩擦阻尼4，冲击阻尼5，磁电效应阻尼,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,工程材料内阻尼产生机理,在应力作用下分子或晶体之间产生相对运动、滑移，消耗能量。,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,流体的粘滞阻尼产生机理,结构和流体接触表面产生能量损耗。,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,结合面阻尼与库仑摩擦阻尼产生机理,零件表面接触并承受动态载荷，产生阻尼。,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,冲击阻尼产生机理,通过附加冲击块，将主系统振动能量转换成冲击块的振动能量。,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,磁电效应阻尼产生机理,机械能转换成电能的过程中，由磁电效应产生阻尼。,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,阻尼材料与阻尼结构,阻尼材料,1，粘弹性阻尼材料2，阻尼涂料3，沥青型阻尼材料4，复合型阻尼金属板材5，阻尼合金6，其它,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,粘弹性阻尼材料,分类：橡胶类、塑料类特性：随温度变化，随频率变化,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,粘弹性阻尼材料随温度变化特性,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,粘弹性阻尼材料随频率变化特性,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,粘弹性阻尼材料耗能综合特性,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,阻尼涂料,组成：高分子树脂等用途：飞机、船舶、车辆、各种机械涂刷注意点：多次涂刷、干透再刷。,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,沥青型阻尼材料,用途：汽车等分类：熔融型、热熔型、自黏型、磁性型。,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,复合型阻尼金属板材,构成：两块金属板之间夹以粘弹性高分子材料用途：汽车、飞机、潜艇、电机、风机等。特点：衰减性好、耐热性好、机械性好、焊接性好、阻燃性等好。,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,阻尼合金,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,其它阻尼材料,玻璃状阻尼陶瓷抗静电阻尼材料抗冲击隔热阻尼材料,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,阻尼基本结构,分类：离散型的阻尼器件附加型的阻尼结构,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,离散型的阻尼器件,分类：减振器（隔振器）吸振器,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,附加型的阻尼结构,分类：直接黏附的阻尼结构（自由层阻尼、约束层阻尼）（多层约束阻尼、插条式阻尼）直接附加固定的阻尼结构（封沙阻尼、空气挤压薄膜阻尼）直接固定组合的阻尼结构（结合面阻尼）,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,自由层阻尼,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,自由层阻尼计算,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,自由层阻尼提高阻尼效果,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,具有隔离层的自由阻尼,隔离层的作用：放大变形,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,约束层阻尼,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,典型的约束层阻尼结构,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,约束层阻尼的阻尼效果,Prof.ShengMeipingNorthwesternPolytechnicalUniversity,本讲基本要求,了解常用阻尼分类及其产生机理自由层阻尼效果分