scholarly journals The effects of voids in quasi-static indentation of resin-infused reinforced polymers

2019 ◽  
Vol 53 (28-30) ◽  
pp. 4399-4410
Author(s):  
SM Sisodia ◽  
DJ Bull ◽  
AR George ◽  
EK Gamstedt ◽  
MN Mavrogordato ◽  
...  
Keyword(s):  
Static Loading ◽  
Tomographic Imaging ◽  
Transverse Cracks ◽  
Reinforced Polymers ◽  
Delamination Growth ◽  
Out Of Plane ◽  
Static Indentation ◽  
Carbon Fibre Reinforced Polymers ◽  
Air Pockets ◽  
Delamination Cracks

The focus of this study is the influence of voids on the damage behaviour in quasi-static loading of resin-infused carbon fibre-reinforced polymers. Experimental results are presented for quasi-static loading in combination with high-resolution tomographic imaging and statistical analysis (homology of pores or voids and induced cracks). Three distinct mechanisms were observed to control delamination growth in the presence of sharp and blunt voids. Delamination cracks interact with the supporting yarns, especially in combination with air pockets trapped in the resin in the form of long, sharp voids. This resulted in crack growth that coalesces with delamination cracks from neighbouring yarn-voids during increased out-of-plane load–displacement, with almost no presence of intralaminar transverse cracks. This highlights the benefits and drawbacks of the supporting yarn during out-of-plane loading.

Fatigue Testing of Carbon Fibre-reinforced Polymers under VHCF Loading*

2012 ◽  
Vol 54 (11-12) ◽  
pp. 756-761 ◽  
Author(s):  
Maik Gude ◽  
Werner Hufenbach ◽  
Ilja Koch ◽  
Roman Koschichow
Keyword(s):  
Carbon Fibre ◽  
Fatigue Testing ◽  
Reinforced Polymers ◽  
Carbon Fibre Reinforced Polymers

Crack Density Evaluation in Carbon Fibre Reinforced Polymers Aged by Thermal Cycling

2016 ◽  
Vol 53 (3) ◽  
pp. 125-143
Author(s):  
S. González ◽  
M. González ◽  
J. Dominguez ◽  
F. Lasagni
Keyword(s):  
Carbon Fibre ◽  
Thermal Cycling ◽  
Crack Density ◽  
Reinforced Polymers ◽  
Carbon Fibre Reinforced Polymers ◽  
Density Evaluation

Computational Investigation of through the Width Delamination of a Composite Laminate using Surface based Cohesive Contact Behaviour

2021 ◽  
Vol 9 (VI) ◽  
pp. 743-747
Author(s):  
K. S. Vishwanath
Keyword(s):  
Composite Laminate ◽  
Weight Ratio ◽  
Computational Prediction ◽  
Shell Elements ◽  
Delamination Growth ◽  
Reinforced Polymer ◽  
Contact Behaviour ◽  
Out Of Plane ◽  
Growth Initiation ◽  
Polymer Laminates

The fiber reinforced polymer laminates have found extensive applications because of its advantages over other materials in terms of strength to weight ratio, manufacturing flexibility and so on. But in the transverse direction, strength is comparatively less so that a failure mechanism called delamination will occur in case of poor manufacturing or when tools are dropped. In this paper, Surface based Cohesive contact behavior is implemented at the interface between base and sub laminate to investigate for 60mm through the width buckling driven delamination growth. The computational prediction of delamination growth initiation is obtained by solving a HTA/6376C composite laminate specimen for geometric non linearity using SC8R continuum shell elements of Abaqus CAE and by plotting the inplane loads versus out of plane displacements.

scholarly journals Laser Interaction with Carbon Fibre Reinforced Polymers

Procedia CIRP ◽  
2015 ◽  
Vol 33 ◽  
pp. 423-427 ◽  
Author(s):  
N. Pagano ◽  
A. Ascari ◽  
E. Liverani ◽  
L. Donati ◽  
G. Campana ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Laser Interaction ◽  
Reinforced Polymers ◽  
Carbon Fibre Reinforced Polymers

scholarly journals Resistance behaviour of carbon fibre-reinforced polymers subjected to lightning strikes: Experimental investigation and application

2019 ◽  
Vol 28 ◽  
pp. 2633366X1989227 ◽  
Author(s):  
Jian Chen ◽  
Zhengcai Fu ◽  
Yang Zhao
Keyword(s):  
Carbon Fibre ◽  
Surface Resistance ◽  
Inflection Point ◽  
Front Surface ◽  
Resistance Change ◽  
Reinforced Polymers ◽  
Change Rate ◽  
Lightning Strikes ◽  
Inflection Points ◽  
Carbon Fibre Reinforced Polymers

It is difficult to monitor lightning damage to carbon fibre-reinforced polymers (CFRPs) online. This work experimentally investigates the changes associated with the electrical resistance of CFRPs subjected to lightning strikes. Two kinds of simulated lightning currents with different amplitudes in the range of 10–80 kA were injected into the CFRP samples. By measuring and comparing the changes in the struck-side (front) surface resistance, the surface resistance of the side opposite to the struck-side (back) and the oblique resistance of each sample before and after the lightning strike, it was observed that inflection points exist in the curve of the resistance change rate. The resistance decreases with increasing peak currents before the inflection point and increases when the peak current goes beyond the inflection point. The change rate of the front surface resistance is more sensitive to the lightning damage than are those of the back surface resistance and the oblique resistance. Different simulated lightning currents have approximately the same action integrals at the inflection points of resistance change rate. The characteristics indicate that resistance change detection could be a possible method for the online monitoring of CFRP lightning damage.

scholarly journals Influence of Gradual Damage on the Structural Dynamic Behaviour of Composite Rotors: Experimental Investigations

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2421 ◽  
Author(s):  
Angelos Filippatos ◽  
Maik Gude
Keyword(s):  
Mechanical Properties ◽  
Composite Structures ◽  
Dynamic Behaviour ◽  
Experimental Investigations ◽  
Catastrophic Failure ◽  
Structural Dynamic ◽  
Delamination Growth ◽  
Reinforced Composite ◽  
Out Of Plane ◽  
Effective Mechanical Properties

Fibre-reinforced composite structures subjected to complex loads exhibit gradual damage behaviour with the degradation of the effective mechanical properties and changes in their structural dynamic behaviour. Damage manifests itself as a spatial increase in inter-fibre failure and delamination growth, resulting in local changes in stiffness. These changes affect not only the residual strength but, more importantly, the structural dynamic behaviour. In the case of composite rotors, this can lead to catastrophic failure if an eigenfrequency coincides with the rotational speed. The description and analysis of the gradual damage behaviour of composite rotors, therefore, provide the fundamentals for a better understanding of unpredicted structural phenomena. The gradual damage behaviour of the example composite rotors and the resulting damage-dependent dynamic behaviour were experimentally investigated under propagating damage caused by a combination of out-of-plane and in-plane loads. A novel observation is the finding that a monotonic increase in damage results in a non-monotonic frequency shift of a significant number of eigenfrequencies.

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