*** Investigation of fatigue crack growth in a single cycle by means of acoustic emission ***
Authors: J.A. Pascoe, D. Zarouchas, R.C. Alderliesten
Structural Integrity & Composites Group, Faculty of Aerospace Engineering, Delft University of Technology

Corresponding author: J.A. Pascoe

Contact Information: 

j.a.pascoe@tudelft.nl

Delft University of Technology - Faculty of Aerospace Engineering
P.O. Box 5058
2600 GB Delft
The Netherlands

Affiliation independent details (should J.A. Pascoe no longer work at the TU Delft in future):

E-mail: johnalan.pascoe@gmail.com
Orchid ID: 0000-0003-2771-8285
ResearcherID: L-2508-2013
Researchgate profile: https://www.researchgate.net/profile/John-Alan_Pascoe/?ev=prf_highl


***General Introduction***

This dataset contains data collected during crack growth experiments at Delft University of Technology, as part of J.A. Pascoe's PhD Thesis project (still in progress at the time of writing, expected completion October 2016).
It is being made public both to act as supplementary data for publications and the PhD thesis of J.A. Pascoe and in order for other researchers to use this data in their own work.

The data in this data set was collected in the Structures and Materials Laboratory of the Delft University of Technology - Faculty of Aerospace Engineering, between August and December 2015.

This research project was made possible by a grant from the Netherlands Organisation for Scientific Research (NWO) Mosaic program, under project number: 017.009.005.

***Purpose of the test campaign***
The purpose of this set of experiments was to investigate the usability of acoustic emission to investigate crack growth in FM94 epoxy adhesive. An acoustic emission system was used to monitor acoustic emissions generated by crack growth in double cantilever bond (DCB) specimens, in which FM94 was used to adhesively bond to Al-2024-T3 arms. The DCB specimens were subjected to a variety of load cases, as detailed in "Text matrix.txt"

***Test equipment***
All tests were performed on a 10 kN MTS fatigue test machine. The crack length was measured by means of a camera system. The acoustic emissions were monitored using an AMSY-6 Vallen, 8-channel acoustic emissions system with 4 parameteric input channels. The sensor used was an AE1045S wisd-band piezoelectric sensor, with an external 34 dB pre-amplifier and a band-pass filter of 20-1200 kHz.
The applied force and displacement were measured by the fatigue test machine, and also sent as inputs to the camera and accoustic emission systems, in order to facilitate synchronisation of the data.

***Description of the data in this data set*** 
The data included in this data set has been grouped per experiment. The files follow the nomenclature system: <Specimen name>-<Test designation>-<Suffix>.<File extension>

The suffix is used to distinguish between the different data files. The various types are explained below:

-Info.txt
Brief notes on the load case and any other important remarks concerning the test.

-AE.csv
Acoustic emission data. This includes the peak amplitude (in dB) and energy content (in aJ = 1e-18 J) of the acoustic signals, and the force and displacement as recorded by the acoustic emission (AE) system. The time at which each measurement was taken, relative to the start of recording on the AE system, is also included. Since the force and displacement data were recorded at fixed intervals, and the acoustic signals were recorded at the moment they were detected, each parameter has it's own matching time value. The time values corresponding to the acoustic signals are in the column labeled 'Time-AE' and the time values corresponding to the force and displacement measurement are in the column labeled 'Time-Load'. 

-Crack.csv
Measured crack lengths, including the force and displacment as recorded by the camera system at the time of the crack length measurement. Also included are the time, and were applicalbe the computed strain energy release rate (computed as G = 3Pd/(wa), G = SERR, P = force, d = displacement, w = specimen width, a = crack length). The time has been matched to the start of recording on the acoustic emission system.

-MTS.dat
Raw data output from the fatigue test machine, containing the recorded force and displacement.

