
*** Damage accumulation analysis of cfrp cross-ply laminates under different tensile loading rates ***

Authors: Xi Li, Milad Saeedifar, Rinze Benedictus, Dimitrios Zarouchas

Structural Integrity & Composites Group, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629HS, The Netherlands


Corresponding author: Dimitrios Zarouchas
 
Contact Information:

d.zarouchas@tudelft.nl

Office NB 0.45
Delft University of Technology - Faculty of Aerospace Engineering
2629 HS Delft
The Netherlands

***General Introduction***
This dataset is being made public both to act as supplementary data for publications and the PhD thesis of Xi Li 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 January 2019 and April 2019.

***Purpose of the test campaign***
The purpose of these experiments was to investigate the loading rate effect on both mechanical properties and damage accumulation process of cross-ply carbon 
fiber-polymer laminates under tensile loading.

***Experimental setup***
The specimens used in the present study were manufactured from the UD carbon fiber Prepreg named Hexply F6376CHTS(12 K)-535%. The nominal fiber weight ratio 
and thickness of the Pregreg are 65% and 0.125 mm, respectively. Two 600 300 mm2 panels were laminated following the stacking sequences of [02 /904 ]S. They 
were then cured inside an autoclave according to the manufacturers recommendation. Afterwards, the panels were cut, using a water-cooling diamond saw, into 
rectangular specimens of 250 mm 25 mm according to ASTM D3039/D3039M-17 standard. Thick paper tabs were glued on both ends of the specimen using cyanoacrylate 
adhesive in order to increase clamping grip. Additionally, both edges of the specimen were covered with thin white paint to enhance the quality for the damage 
monitoring with the edge cameras. Finally, a white base coat was painted on the front surface of specimen and then designed speckle pattern with the dot size 
of 0.18 mm were printed on the surface using a VIC speckle roller to prepare the DIC inspection area.

Tensile tests were carried out on a 60 kN fatigue machine with hydraulic grips. Five levels of loading rates were performed under load and displacement control 
mode. To guarantee the repeatability of test results, five specimens were tested under each loading rate while specimens that fail at the clamps were excluded 
from the analysis. The AE, DIC and edge damage monitoring systems were synchronized with the testing machine to create a synergistic work environment among 
different devices.

Two 9 Megapixel cameras with 50 mm lens and 150 frames-per-second were placed at left and right side of the testing machine to monitor cracks occurred on both
edges of the specimen. A total length of 100 mm for each edge was observed during the test.  

Two broadband VS900-M AE sensors with a diameter of 20.3 mm and a frequency range of 100900 kHz were clamped on the specimen. The distance between two sensors 
was fixed to 100 mm for all tests. Vacuumed silicon grease was used between the AE sensor and the specimen surface to create good acoustical coupling. The AMSY-6 
8-channel Vallen system was used to record the AE activity and two pre-amplifiers with gain of 34 dB and band-pass filter of 201200 kHz were used to connect the 
sensors to the AE system. In all tests, the sampling rate and threshold were set as 2 MHz and 45 dB, respectively.

A pair of 5 Megapixel cameras with 23 mm lens and 75 frames-per-second was placed in front of the testing machine to apply DIC at the exterior 0 ply of specimens. 
A subset size of 29 pixels and step size of 7 pixels were selected for correlation analysis. The length of the view field for in-situ strain measurement was 
approximately 7080 mm.

***Description of the data in this data set***
The data included in this dataset has been organised to separate xls-files based on the figures in the related publication.
