摘要
现有振动传递特性测试装置存在如下不足:(1)国家标准GB/T 8169-2008中振动传递特性装置只能进行双层缓冲材料测试,无法反映材料本身特性,同时其采用的整体式质量系统在进行多个载荷测试时需要准备较多规格质量块,成本较高;(2)单层振动传递特性装置解决了材料本身的测试问题,但装置制作成本和安装复杂度高,同时配套的秤砣式质量系统由于其重心不在几何中心容易导致质量块的重心偏移导杆中心,影响质量块的竖直运动。为解决上述不足,设计开发了直接固定于振动台台面的单层缓冲材料振动传递特性测试装置。装置主要包括2个部分,质量导向装置和质量系统。其中质量系统本身由活结螺杆与砝码式质量块快速组合形成,其质量在1.95kg~23.48kg可调。质量导向装置直接固定于振动台台面。质量系统与质量导向装置配合能保证在振动过程中只进行竖直方向运动。利用该装置采用密度为20kg/m3的EPO(Expanded Polyolefin)塑料泡沫进行了2种载荷条件下的正弦扫频振动传递特性试验,得到了各自的传递率-频率关系曲线;进一步采用万能材料试验机和DMA(Dynamic Mechanical Analysis)分别进行静态压缩和压缩模式扫频试验,得到了对应2种静应力下的弹性模量和损耗因子数值;再按照单自由度有阻尼系统受迫振动的理论,计算出对应的共振频率和传递率数据并与该装置的测试结果进行比较,结果表明共振频率和传递率误差都在10%以内。利用本文所设计的装置可以快速得到缓冲材料本身在不同静应力条件下的振动传递特性曲线,再根据曲线的峰值传递率可进一步计算得到材料的阻尼特性参数。
The existing vibration transmissibility characteristic test device has the following shortcomings:(1)The vibration transmissibility characteristic device in the national standard GB/T 8169-2008 can only carry out double-layer cushioning material test,which cannot reflect the characteristics of the material itself.At the same time,it needs to prepare more specifications of mass blocks when using the integral mass system to carry out multiple loading tests,and the cost is high.(2)The single-layer vibration transmissibility characteristic device solves the test problem of the material itself,but the device has high production cost and installation complexity.The matching weight type mass system,due to its center of gravity not being in the geometric center,can easily cause the center of gravity of the mass block to deviate from the center of the guide rod,affecting the vertical movement of the mass block.To solve the above shortcomings,a vibration transmissibility characteristic testing device is designed and developed for a single-layer cushioning material directly fixed to the vibration table surface.The device mainly consists of two components,the guiding device of mass and the mass system.The mass system itself is formed by the quick combination of the slipknot screw and the weight type mass block,and its mass is adjustable from 1.95kg to 23.48kg.The mass guiding device is directly fixed on the vibration table surface.And the cooperation of the mass system and the mass guiding device can ensure that the mass system only moves in the vertical direction during the vibration process.Based on the device,the sinusoidal sweep vibration transmissibility characteristics test under the two loads was carried out by using the EPO(Expanded Polyolefin)plastic foam with a density of 20kg/m^(3),and the relationship curve of transmissibility-frequency were obtained respectively;further,the universal material testing machine and DMA(Dynamic Mechanical Analysis)were used to carry out static compression and compression mode sweep tests respectively,and the elastic modulus and loss factor values corresponding to the two static stresses were obtained.According to the theory of forced vibration of single-degree-of-freedom damped system,the corresponding resonance frequency and transmissibility data were calculated and compared with the test results of the device.The results show that the errors of the resonance frequency and the transmissibility are both within 10%.Using the device designed in this paper,the vibration transmissibility characteristic curve of the cushioning material itself under different static stresses can be quickly obtained,then the damping characteristic parameters of the material can be further calculated according to the peak transmissibility rate of the curve.
作者
李毅
温时宝
于振
王继微
张振秀
LI Yi;WEN Shibao;YU Zhen;WANG Jiwei;ZHANG Zhenxiu(School of Polymer Science and Engineering,Qingdao University of Science and Technology,Qingdao 266042,Shandong,China)
出处
《实验力学》
CSCD
北大核心
2023年第5期655-664,共10页
Journal of Experimental Mechanics
关键词
缓冲材料
振动传递特性
固有频率
阻尼比
固定装置
质量系统
cushioning material
vibration transmissibility characteristics
natural frequency
damping ratio
fixture
mass system
