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激光时间平均全息干涉法系一种非接触式高灵敏度振动测试方法,可方便地获得振型全场精确分布,对小质量小刚度试件特别适用。全息像条纹密度的控制等问题,全息法本身并不能解决。本文将全息法与砂型法相结合,由砂型法取得控制全息像条纹密度的信息,并给出了控制条纹级的表达式,克服了试凑的缺点。在振型正交化处理中,鉴于Gravitz法对高阶振型不够精确、McGrew法要求以精确的第一阶振型为基础,本文将两法结合使用,避开了两法固有的缺点。通过对两后掠翼模型振型的测定,说明本文方法是行之有效的。用HAJIF—Ⅱ对一个模型进行了计算,结果表明,所得数据与本文方法取得的实测数据相当吻合。本文提供的正交化实测振型,可作为模态综合法或气弹模型的有关数据。
Laser time-averaged holographic interferometry is a non-contact high-sensitivity vibration test method, which can easily obtain accurate distribution of mode shapes and is especially suitable for low-mass and small-stiffness specimens. Holography like the control of streak density and other issues, the holographic method itself can not be solved. In this paper, the holographic method is combined with the sand-type method to get the information of controlling the streak density by the holographic method. The expression of the control streak level is also given, which overcomes the shortcomings of the trial and error. In the modal orthogonalization, given that the Gravitz method is not accurate enough for the high-order modes, the McGrew method requires accurate first-order modes as the basis. In this paper, the two methods are combined to avoid the inherent disadvantages of the two methods. The determination of the mode shapes of the two swept-back wings shows that the method in this paper is effective. A model was calculated using HAJIF-II. The results show that the data obtained are in good agreement with the measured data obtained by this method. This article provides the orthogonalization of the measured vibration mode, which can be used as the modal synthesis method or the relevant data of the aeroelastic model.