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在运载工具(如导弹、飞机、坦克车辆、舰船等)、大型机组以及各类机床、泵、风动工具等机电设备上,对于控制一些大型幅板、壳体、管道、桁梁以及梁(筋)—板组合结构等轻型连续构件所激发的振动和强噪声,人们往往会束手无策。这类结构一旦被外力激发,则在局部产生共振,形成二次噪声,严重的甚至发生疲劳破坏。显然,这种场合的减振与降噪将被限于共振(包括局部共振)的区域内,亦即是“阻尼控制区域”,所采取的措施最有效的是增加声源(或振源)系统内部的能量损耗或者传递途径中的传递能量损耗。 早在五个年代初期,国外在航空航天工程中开始采用以粘弹性材料为蕊层的复合阻尼结构进行减振和降噪。三十年来国外在理论和实践上都做了大量的工作,并广泛运用于各种低噪声产品设计以及环境治理、劳动保护工程中。 国内近年来也开始了这项研究和实践,并引起了不少单位的兴趣和重视。本文仅简单地介绍阻尼结构的一些类型,概述结构设计的基本出发点以及应用实例。
In the control of some large-scale panels, housings, pipelines, girders and beams on vehicles (such as missiles, aircraft, tank vehicles, ships, etc.), large units and various types of machine tools, pumps, pneumatic tools and other mechanical and electrical equipment, (Tendons) - plate combination structure and other light continuous components excited by the vibration and strong noise, people tend to be at a loss what to do. Once excited by external forces, such structures resonate locally, form secondary noise, and even cause severe fatigue damage. Obviously, the vibration reduction and noise reduction in this case will be limited to the area of resonance (including local resonance), that is, the “damping control area”. The most effective measure is to increase the sound source (or vibration source) system Internal energy loss or transfer of energy in the transmission path. As early as the early 1950s, foreign countries began to adopt aerodynamic composite damping structures with viscoelastic materials for damping and noise reduction in aerospace engineering. Thirty years abroad have made a lot of work in theory and practice, and are widely used in various low-noise product design and environmental management and labor protection projects. In recent years, China has also started this research and practice, and aroused the interest and attention of many units. This article only briefly introduces some types of damping structures, summarizes the basic starting point of structural design and application examples.