阻尼作用及产生机理阻尼材料与阻尼结构

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,噪声与振动控制技术,主讲：盛美萍,Prof.,Sheng,Meiping,Northwestern,Polytechnical,University,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.,Sheng,Meiping,Northwestern,Polytechnical,University,阻尼作用及产生机理,阻尼材料与阻尼结构,Prof.,Sheng,Meiping,Northwestern,Polytechnical,University,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.,Sheng,Meiping,Northwestern,Polytechnical,University,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.,Sheng,Meiping,Northwestern,Polytechnical,University,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。,B,O,C,D,A,应变,应力,P,Prof.,Sheng,Meiping,Northwestern,Polytechnical,University,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。,无粘流体,粘滞流体,Prof.,Sheng,Meiping,Northwestern,Polytechnical,University,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。,O,O,B,C,P,C,B,P,Prof.,Sheng,Meiping,Northwestern,Polytechnical,University,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.,Sheng,Meiping,Northwestern,Polytechnical,University,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。,磁极,金属导磁片,Prof.,Sheng,Meiping,Northwestern,Polytechnical,University,Prof.,Sheng,Meiping,Northwestern,Polytechnical,University,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.,Sheng,Meiping,Northwestern,Polytechnical,University,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.,Sheng,Meiping,Northwestern,Polytechnical,University,粘弹性阻尼材料随温度变化特性,Prof.,Sheng,Meiping,Northwestern,Polytechnical,University,粘弹性阻尼材料随频率变化特性,Prof.Sheng Meiping,Northwestern Polytechnical University,粘弹性阻尼材料耗能综合特性,Prof.Sheng Meiping,Northwestern Polytechnical University,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.Sheng Meiping,Northwestern Polytechnical University,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.Sheng Meiping,Northwestern Polytechnical University,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.Sheng Meiping,Northwestern Polytechnical University,阻尼合金,Prof.Sheng Meiping,Northwestern Polytechnical University,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.Sheng Meiping,Northwestern Polytechnical University,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.Sheng Meiping,Northwestern Polytechnical University,离散型的阻尼器件,分类：,减振器（隔振器）,吸振器,Prof.Sheng Meiping,Northwestern Polytechnical University,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.Sheng Meiping,Northwestern Polytechnical University,自由层阻尼,H,2,H,1,H,21,基本弹性层,阻尼层,Prof.Sheng Meiping,Northwestern Polytechnical University,自由层阻尼计算,Prof.Sheng Meiping,Northwestern Polytechnical University,自由层阻尼提高阻尼效果,Prof.Sheng Meiping,Northwestern Polytechnical University,具有隔离层的自由阻尼,隔离层的作用：放大变形,H,2,H,1,H,31,基本弹性层,阻尼层,H,3,隔离层（扩变层）,Prof.Sheng Meiping,Northwestern Polytechnical University,约束层阻尼,H,2,H,1,H,31,基本弹性层,约束层,H,3,阻尼层,Prof.Sheng Meiping,Northwestern Polytechnical University,典型的约束层阻尼结构,Prof.Sheng Meiping,Northwestern Polytechnical University,约束层阻尼的阻尼效果,Prof.Sheng Meiping,Northwestern Polytechnical University,本讲基本要求,了解常用阻尼分类及其产生机理,自由层阻尼效果分析,约束层阻尼效果分析,Prof.Sheng Meiping,Northwestern Polytechnical University,实验预告,混响时间与结构阻尼测试,Prof.Sheng Meiping,Northwestern Polytechnical University,