Temperature-dependent Lamb wave signals in highly anisotropic CFRP

The dataset contains signals of propagating Lamb waves in highly anisotropic carbon fibre reinforced polymer (CFRP). The reinforcement is unidirectional along 0 deg. A detailed description of the material and its parameters is given in [1]. The arrangement of piezoelectric actuator A and sensors S1-S7 is shown in figure "plate_angular_pzt_arrangement_50x50.png". Sensors are placed at propagation angles from 0 deg to 90 deg with a step of 15 deg. It should be noted that two piezoelectric transducers bonded to both sides of the plate were used as the actuator. It allowed for exciting Lamb waves with dominant A0 and S0 modes, respectively. Hence, there are two respective zip files with data.

The following parameters were used during measurements:

Temperatures: T=[50,40,30,20,10,0,-10,-20,-30,-40,-50];

Number of cycles in Hann windowed signals: no_of_cycles=[2,2.5,3];

Carrier frequencies of excitation signals [kHz]: frequencies=[20:10:250];

Number of averages: 50;

Sampling frequency: 10 MHz.

The following equipment was used in the experiment:

Environmental chamber by Angelantoni Test Technologies, model MyDiscovery 600 C;

National Instruments waveform generator PXIe-5413;

Krohn-Hite voltage amplifier model 7500;

Cedrat Technologies LWDS amplifier (used as a charge amplifier);

National Instruments oscilloscope PXIe-5105.

Files in CSV format contain environmental chamber data (temperature programme, actual temperature and humidity over time, etc.). This can be read and plotted in Matlab by running the script “Read_plot_environmental_chamber.m”. There is another file “Read_plot_environmental_chamber_plus_DS18B20_RH20_KROHN_A0.m” in which temperature was registered also by DS18B20 digital sensor. It loops over all measurements so that it can be used also for reading signals from “niscope_avg_waveform.mat” in respective subfolders. In particular, sensor signals are stored in the “niscope_avg_waveform” variable, a matrix of dimensions 8192x7.