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加筋板是航天器上的常用结构。为研制基于声发射技术的在轨感知系统,需要研究加筋板中声发射波传播规律及撞击源定位方法。文章测定了断铅信号在加筋板中的传播速度,对沿不同方向传播的波速进行了比较;通过有限元仿真,研究了筋体几何尺寸对板中声发射信号传播规律的影响。试验与仿真的结果表明:筋体对信号压缩波波速影响较小,但会造成信号第一幅值的衰减,在传感器布局设计时需要考虑到该因素。将加筋板中声发射信号传播速度取为沿不同方向传播波速的平均值,可将源定位问题转化成求取函数最小值的优化问题,在加筋板上对断铅波源和超高速撞击波源进行定位效果较好。
Stiffened panels are common structures on spacecraft. In order to develop the on-orbit sensing system based on acoustic emission technology, it is necessary to study the propagation law of acoustic emission waves in stiffened plates and the method of locating the impact source. In this paper, the propagation velocity of broken lead signal in stiffened plates was measured and the wave velocities propagated in different directions were compared. The influence of the geometry of stiffeners on the propagation of acoustic emission signals in the slab was studied by finite element simulation. The results of the experiment and simulation show that the ribs have less influence on the speed of the signal compression wave, but will attenuate the first amplitude of the signal. This factor needs to be considered when designing the sensor layout. The velocity of acoustic emission signal in stiffened plate is taken as the average value of wave velocity in different directions so that the source localization problem can be transformed into the optimization problem of obtaining the minimum value of function. In the stiffened plate, the lead-wave source and hypervelocity impact Wave source positioning effect is better.