随机锤击法识别专用车架结构模态参数

结构动态试验中,用锤击法识别结构模态参数,近几年来已被广泛应用,通常锤击法激振能量有限,测得激励和响应数据信噪比甚低,影响模态参数识别的成败。本文提出用一种随机锤击法识别结构模态参数,它能将更多能量输入结构,提高了数据的信噪比,加快了试验速度。本文结合具体数据作出了论证。在4 t重复杂汽车吊专用车架上仅用280g重的小力锤,满意地获得了结构模态参数,并且与一般锤击法试验作了对比分析。

Identification of Modal Parameters for SpecialAutomobile Frames with a Random Impulse Technique

Recently an impulse technique to identify structural modal parameters is extensively used in the structural dynamical test. In general, because of the limited excited energy with the impulse technique, the signal-noise ratio of excitation and response data is very low, so that it will influence the quality of identification. This paper presents a random impulse technique to identify the structural modal parameters. The method has following advantage: It can input more energy into the structures, so that it will improve the signal-noise ratio data and speed up the test process. In the paper, this method is used for identification of the modal parameters of the frame of the automobile crane weighing 4 tons, with a small-hammer weighing of only 280 grams in the test. The measurements of the structural modal parameters are very satisfactory.