scholarly journals An Experimental and Numerical Investigation to Characterize an Aerospace Composite Material with Open-Hole Using Non-Destructive Techniques

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4148 ◽  
Author(s):  
Norberto Feito ◽  
José Vicente Calvo ◽  
Ricardo Belda ◽  
Eugenio Giner
Keyword(s):  
Strain Distribution ◽  
Stress Concentrator ◽  
Image Correlation ◽  
Fiber Waviness ◽  
Static Tests ◽  
Manufacturing Defects ◽  
Open Hole ◽  
Static Tensile ◽  
Non Destructive ◽  
Non Destructive Techniques

In this study, the open-hole quasi-static tensile and fatigue loading behavior of a multidirectional CFRP thick laminate, representative of laminates used in the aerospace industry, is studied. Non-destructive techniques such as infrared thermographic (IRT) and digital image correlation (DIC) are used to analyze the behavior of this material. We aim at characterizing the influence of the manufacturing defects and the stress concentrator through the temperature variation and strain distribution during fatigue and quasi-static tests. On the one hand, the fatigue specimens were tested in two main perpendicular directions of the laminate. The results revealed that manufacturing defects such as fiber waviness can have a major impact than open-hole stress concentrator on raising the material temperature and causing fracture. In addition, the number of plies with fibers oriented in the load direction can drastically reduce the temperature increment in the laminate. On the other hand, the quasi-static tensile tests showed that the strain distribution around the hole is able to predict the crack initiation and progression in the external plies. Finally, the experimental quasi-static tests were numerically simulated using the finite element method showing good agreement between the numerical and experimental results.

The effect of microfibrils cellulose modified epoxy on the quasi-static and fatigue behaviour of open hole carbon textile composites

2018 ◽  
Vol 52 (24) ◽  
pp. 3365-3380 ◽  
Author(s):  
Valter Carvelli ◽  
Toru Fujii ◽  
Kazuya Okubo
Keyword(s):  
Mechanical Performance ◽  
Fatigue Behaviour ◽  
Textile Composites ◽  
Image Correlation ◽  
Cellulose Microfibrils ◽  
Micro Computed Tomography ◽  
The Matrix ◽  
Open Hole ◽  
Static Tensile ◽  
Modified Epoxy

The extensive experimental investigation aimed to assess the effects of hybrid epoxy resin with micro-fibrillated cellulose on tensile quasi-static and fatigue behaviour of open hole carbon plain weave composites. The hybridization of the matrix allowed an improved damage tolerance of the composite leading to increase of the quasi-static tensile strength and extension of the fatigue life. The enhanced mechanical performance of the notched composites was connected to the bridging effect of cellulose microfibrils preventing or delaying the cracks propagation in the matrix and along the fibres interface. The better distribution of the stress state was assessed by digital image correlation strain maps around the hole and the imparted fatigue damage was analysed by scanning electron microscope and X-ray micro-computed tomography visualizations.

scholarly journals Measurement of Interlaminar Tensile Strength and Elastic Properties of Composites Using Open-Hole Compression Testing and Digital Image Correlation

2019 ◽  
Vol 9 (13) ◽  
pp. 2647 ◽  
Author(s):  
Guillaume Seon ◽  
Andrew Makeev ◽  
Joseph D. Schaefer ◽  
Brian Justusson
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Standard Test ◽  
Image Correlation ◽  
Stress Strain ◽  
Aircraft Structures ◽  
Full Field ◽  
Manufacturing Defects ◽  
Open Hole ◽  
Properties Of Composites

Advanced polymeric composites are increasingly used in high-performance aircraft structures to reduce weight and improve efficiency. However, a major challenge delaying the implementation of the advanced composites is the lack of accurate methods for material characterization. Accurate measurement of three-dimensional mechanical properties of composites, stress–strain response, strength, fatigue, and toughness properties, is essential in the development of validated analysis techniques accelerating design and certification of composite structures. In particular, accurate measurement of the through-thickness constitutive properties and interlaminar tensile (ILT) strength is needed to capture delamination failure, which is one of the primary failure modes in composite aircraft structures. A major technical challenge to accurate measurement of ILT properties is their strong sensitivity to manufacturing defects that often leads to unacceptable scatter in standard test results. Unacceptable failure mode in standard test methods is another common obstacle to accurate ILT strength measurement. Characterization methods based on non-contact full-field measurement of deformation have emerged as attractive alternative techniques allowing more flexibility in test configuration to address some of the limitations inherent to strain gauge-based standard testing. In this work, a method based on full-field digital image correlation (DIC) measurement of surface deformation in unidirectional open-hole compression (OHC) specimens is proposed and investigated as a viable alternative to assessing ILT stress–strain, strength, and fatigue properties. Inverse identification using a finite element model updating (FEMU) method is used for simultaneous measurement of through-thickness elastic constants with recovery of the maximum ILT stress at failure for characterization of strength and fatigue S–N curves.

scholarly journals Post-Impact Behaviour of Pseudo-Ductile Thin-Ply Angle-Ply Hybrid Composites

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 579 ◽  
Author(s):  
Alessia Prato ◽  
Marco Longana ◽  
Ambreen Hussain ◽  
Michael Wisnom
Keyword(s):  
Strain Distribution ◽  
Hybrid Composites ◽  
Tensile Load ◽  
Tensile Loading ◽  
Tensile Tests ◽  
Image Correlation ◽  
Impact Behaviour ◽  
Damage Propagation ◽  
Post Impact ◽  
Non Destructive

This work experimentally explores the post-impact behaviour of thin-ply angle-ply pseudo-ductile carbon fibre laminates subjected to tensile load. Indentation and low-speed impact tests were performed on standard tensile test specimens. Non-destructive tests were used to investigate the damage propagation. Digital Image Correlation (DIC) was adopted to detect the strain distribution during tensile tests. Post-damage pseudo-ductile behaviour was retained in angle-ply hybrid composites subjected to tensile loading conditions.

How to combine several non-destructive techniques for a better assessment of concrete structures

2008 ◽  
Vol 38 (6) ◽  
pp. 783-793 ◽  
Author(s):  
D. Breysse ◽  
G. Klysz ◽  
X. Dérobert ◽  
C. Sirieix ◽  
J.F. Lataste
Keyword(s):  
Concrete Structures ◽  
Non Destructive ◽  
Non Destructive Techniques
Sign in / Sign up

Export Citation Format

Share Document