基于频率响应灵敏度的车身结构的优化设计

针对车身优化的问题,采用频率响应灵敏度分析来降低车身结构的响应位移。在车身有限元模型的基础上计算频率响应,并求得驾驶员座椅支架处的响应位移曲线,从中找出某频率处的振动峰值;为了降低振动峰值,通过频率响应灵敏度分析选择合适的设计变量进行优化计算。优化后车身关键频率处的响应位移明显减小,提高乘坐的舒适性。

压电加速度计不同安装方式对灵敏度频率响应的影响

提出了比较法中频振动标准装置中不同安装方式对压电加速度计灵敏度频率响应的影响,并进行试验研究。通过不同测量结果的比较,得出了在对压电加速度计进行比较法校准时选择合理的安装方式,对规范和完善压电加速度计的校准过程有非常重要的意义,并能够保证压电加速度计灵敏度有良好的频率响应特性。

Testing an improved cymbal hydrophone

Cymbal hydrophones have small volume and high sensitivity, but their reception is not stable enough, and their reception is in too narrow a frequency band. In order to overcome these inadequacies, the structure of the cymbal hydrophone was improved. The single ceramic piezoelectric element was replaced with a double one, the radius of the ceramic piezoelectric element was reduced, and a parallel circuit was added. A static analysis of this new structure was developed, and then simulations were made of both the traditional and new hydrophone structure using finite element software. Tests were then conducted in a tank. The results showed that the improved hydrophone has reception in a wider frequency band, reception performance is stable within this frequency band, and sensitivity is still high.

压电加速度计测量结果不确定度评定

压电加速度计非常适合测量在液压和气动扰动、脉冲(冲击)力、机械和设备振动、烟火冲击等中发现的高频加速度信号。因其频率及动态测量范围广,稳定性好,易用性强的优势,现阶段压电加速度计已广泛应用诸多行业,伴随着市面压电加速度计的种类日益增多,相应的校准需求也随之增加,本文依据压电加速度计检定规程中的比较测量法,使用BK8305作为参考加速度计,VE-4125作为标准振动台结合MI-2004电荷放大器与EC-9102程控标定仪等配套软硬件,对单向工作加速度计的灵敏度幅值、灵敏度响应频率、灵敏度幅值线性度的计量特性进行校准试验。此次试验主要针对加速度幅值范围0~100 m/s^(2),测量频率不大于5 kHz的压电加速度计。依据校准压电加速度计过程中产生的测量数据,分析试验过程中的标准不确定度量的来源,结合标准器溯源证书以及相关计量规范中对配套仪器计量特性要求,对压电加速度计的测量结果进行了不确定度评定。校准证书在出具校准结果的同时也应包含测量不确定度,测量不确定度是用以表征合理赋予被测量的值的分散性,作为测量结果含有的一个参数。