39 Study on AE Detection Signal of Composite Barrel Under …
443
uses Vallen’s acoustic emission detection system. VS150 is selected as sensors with
4 channels and 4 acquisition channels.
Each sensor is connected to the instrument channel through a single-ended preamplifier. Medical Vaseline is used as the coupling agent between the probe and the test
piece. The instrument settings and probe parameters are: instrument main amplifier gain 20 dB; gain threshold 40 dB; front amplifier gain 40 dB; sensors center
frequency 150 kHz; no pre-filtering.
39.2.3 Test Process
The loading process: 200 kN → 400 kN → 600 kN → 700 kN → 800 kN →
900 kN → 950 kN → 1000 kN → 1050 kN → 1100 kN. AE signal waveform and
characteristic parameters were collected during the test.
39.3 Test Result and Analysis
The failure load is 1000.80 kN. During the first six level loading, the test piece was
normal. During loading level 7, Slight sound detected. During loading level 8, A
loud sound after a click before the final failure, which caused product failure results.
when the load was unloaded to 0, the deformation of the test piece restored basically.
Figure 39.2 is the AE process diagram, The entire axial pressure failure stage is
mainly divided into three stages, the threshold value is 40 dB, During the entire axial
pressure failure process, the amplitude distribution of AE time is 40–100 dB, and
the energy distribution is 0–2.6 × 10
9 , the duration is between 0 and 1.29 S.
In the first stage (0–193 s), it can be seen from the AE process diagram that the hits
at this stage is little and the amplitude of this stage is small, most of which are below
70 dB, and the corresponding energy is also small. The duration is basically below
500 µm, and the duration of individual signal points is between 500 and 1000 µm.
This is mainly due to the bearing capacity of the test piece. In the initial stage of
the axial compression test, the deformation of the material is mainly the elastic
deformation of the matrix in the composite Mainly, there are fractures of individual
microfibers. From the displacement data during the test, it can be seen that during
the loading process of the first three stages, the test piece has a deformation of about
1.2 mm.
Analysis of the waveforms at this stage shows that there are two types of waveforms at this stage. One is that the frequency is around 500 kHz (Fig. 39.3), the
amplitude is below 60 dB, and the duration is relatively short. This type of signal is
mainly used in combination with the above analysis. According to preliminary judgment, this type of waveform should be a waveform signal generated by the elastic
deformation process of the composite matrix during loading; the other is a frequency
of about 140 kHz (Fig. 39.4), and the duration is Between 500 and 1000 µm, the
443
uses Vallen’s acoustic emission detection system. VS150 is selected as sensors with
4 channels and 4 acquisition channels.
Each sensor is connected to the instrument channel through a single-ended preamplifier. Medical Vaseline is used as the coupling agent between the probe and the test
piece. The instrument settings and probe parameters are: instrument main amplifier gain 20 dB; gain threshold 40 dB; front amplifier gain 40 dB; sensors center
frequency 150 kHz; no pre-filtering.
39.2.3 Test Process
The loading process: 200 kN → 400 kN → 600 kN → 700 kN → 800 kN →
900 kN → 950 kN → 1000 kN → 1050 kN → 1100 kN. AE signal waveform and
characteristic parameters were collected during the test.
39.3 Test Result and Analysis
The failure load is 1000.80 kN. During the first six level loading, the test piece was
normal. During loading level 7, Slight sound detected. During loading level 8, A
loud sound after a click before the final failure, which caused product failure results.
when the load was unloaded to 0, the deformation of the test piece restored basically.
Figure 39.2 is the AE process diagram, The entire axial pressure failure stage is
mainly divided into three stages, the threshold value is 40 dB, During the entire axial
pressure failure process, the amplitude distribution of AE time is 40–100 dB, and
the energy distribution is 0–2.6 × 10
9 , the duration is between 0 and 1.29 S.
In the first stage (0–193 s), it can be seen from the AE process diagram that the hits
at this stage is little and the amplitude of this stage is small, most of which are below
70 dB, and the corresponding energy is also small. The duration is basically below
500 µm, and the duration of individual signal points is between 500 and 1000 µm.
This is mainly due to the bearing capacity of the test piece. In the initial stage of
the axial compression test, the deformation of the material is mainly the elastic
deformation of the matrix in the composite Mainly, there are fractures of individual
microfibers. From the displacement data during the test, it can be seen that during
the loading process of the first three stages, the test piece has a deformation of about
1.2 mm.
Analysis of the waveforms at this stage shows that there are two types of waveforms at this stage. One is that the frequency is around 500 kHz (Fig. 39.3), the
amplitude is below 60 dB, and the duration is relatively short. This type of signal is
mainly used in combination with the above analysis. According to preliminary judgment, this type of waveform should be a waveform signal generated by the elastic
deformation process of the composite matrix during loading; the other is a frequency
of about 140 kHz (Fig. 39.4), and the duration is Between 500 and 1000 µm, the