Hill R, Forsyth S A, Macey P
Department of Chemistry and Physics, Clifton Campus, Nottingham Trent University, Nottingham NG11 8NS, UK.
Ultrasonics. 2004 Apr;42(1-9):253-8. doi: 10.1016/j.ultras.2004.01.018.
Finite element (FE) modelling has a role to play in simulating elastic wave propagation associated with structural vibrations, acoustic phenomena and ultrasound problems. In this work we have used the PAFEC software [PAFEC finite element software PACSYS, Strelley Hall, Nottingham, NG8 6PE, UK]. With the advent of increased computer power and greater availability of software these simulations have become more readily available and will provide improved insight into wave propagation problems. Simulations have been undertaken of transient wave propagation in steel plates with an attached simple resonant transducer. This simulates acoustic emission (AE) propagation in plate like structures relevant to many industrial applications. Simulations for short propagation distances suggest the resonant transducer voltage signal carries information on the plate-waves propagating in the structure, overlaid with the piezoelectric resonance and some information might be extracted from the transducer signal. Looking at the wave propagation information alone, a great deal of variability is seen in the displacement profile for different source types, orientations and locations. Although users have expressed a need for calibration of the AE detection process, this idea remains problematic since the complete generation and detection system has the features of a chaotic system. Using FE modelling a method of "point calibration" might be available, for some specific AE applications such as crack growth along known paths.
有限元（FE）建模在模拟与结构振动、声学现象和超声问题相关的弹性波传播方面发挥着作用。在这项工作中，我们使用了PAFEC软件[PAFEC有限元软件PACSYS，英国诺丁汉NG8 6PE斯特雷利厅]。随着计算机能力的提高和软件可用性的增加，这些模拟变得更容易实现，并将为波传播问题提供更深入的见解。我们对带有简单共振换能器的钢板中的瞬态波传播进行了模拟。这模拟了与许多工业应用相关的板状结构中的声发射（AE）传播。短传播距离的模拟表明，共振换能器电压信号携带了关于在结构中传播的板波的信息，叠加有压电共振，并且可以从换能器信号中提取一些信息。仅看波传播信息，对于不同的源类型、方向和位置，位移轮廓存在很大的变异性。尽管用户表示需要对AE检测过程进行校准，但由于整个生成和检测系统具有混沌系统的特征，这个想法仍然存在问题。使用有限元建模，对于一些特定的AE应用，如沿已知路径的裂纹扩展，可能会有一种“点校准”方法。
