通过模拟声发射研究增材制造零件中的损伤特性

Investigating Damage Characteristics in Additive Manufactured Parts by Simulating Acoustic Emission

基于有限元方法模拟的单轴拉伸试验,研究了具有不同孔洞位置的两种增材制造铝板的波传播特性。本文使用有限元方法获得所需的数据,并应用信号分析方法进行数据处理。开展了4种数据分析,综合考察波的传播特性即波形分析、声发射参数分析、频域分析和波数-频域分析。研究表明,此两种铝板可以通过直接观察波形或比较主要的兰姆波模态来区分。孔洞在50%位置的板的波形围绕平衡位置上下振荡,孔洞在75%位置的板的波形不规则。对于兰姆波模态,50%位置的板在S1和A1模态中能量最强,75%位置的板有多个主导兰姆波模态。这两种铝板有一个共同点,都有大约300 kHz的高能量兰姆波模态。此外,研究也表明声波传播距离会影响声发射参数和频率。峰值振幅、上升时间和这两种参数的比值与距离呈单调关系,而峰值频率和中心频率则在整个距离范围内波动。

This paper investigates wave propagation characteristics of two additive manufactured aluminium plates with different cavity positions under a uniaxial tensile loading test.The finite element method is conducted to obtain desired data,and signal analysing strategies will be applied for data processing.Four types of data analyses have been carried out in this paper to comprehensively investigate wave propagation characteristics:waveform analysis,AE parameter analysis,frequency domain analysis and wavenumber-frequency domain analysis.The results show that these two aluminium plates can be distinguished by directly observing the wave shape or comparing dominant Lamb wave modes.Waveforms of 50%position plate are oscillating up and down around equilibrium position,while waveforms of 75%position plate are irregular.As for Lamb wave modes,50%position plate has the strongest energy in S1 and A1 modes,while 75%position plate has multiple dominant Lamb wave modes.But one thing the two plates have in common is that there are high-energy Lamb wave patterns around 300 kHz in both plates.Also,it is indicative that wave propagation distance affects AE parameters and frequency.Peak amplitude,rise time and RA show monotonical relation with distance,whilst peak frequency and central frequency fluctuate through the whole distance.