阻尼作用及产生机理阻尼材料与阻尼结构.ppt

噪声与振动控制技术主讲：盛美萍•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity阻尼作用及产生机理阻尼材料与阻尼结构•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity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。BOCDA应变应力P•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity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。OO’BCPC’B’P’•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity粘弹性阻尼材料随温度变化特性•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity粘弹性阻尼材料随频率变化特性•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity粘弹性阻尼材料耗能综合特性•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity阻尼合金•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity离散型的阻尼器件•分类：•减振器（隔振器）•吸振器•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity自由层阻尼H2H1H21基本弹性层阻尼层•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity自由层阻尼计算•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity自由层阻尼提高阻尼效果•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity具有隔离层的自由阻尼•隔离层的作用：放大变形H2H1H31基本弹性层阻尼层H3隔离层（扩变层）•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity约束层阻尼H2H1H31基本弹性层约束层H3阻尼层•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity典型的约束层阻尼结构•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity约束层阻尼的阻尼效果•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity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.ShengMeiping•NorthwesternPolytechnicalUniversity实验预告•混响时间与结构阻尼测试•Prof.ShengMeiping•NorthwesternPolytechnicalUniversity