Numerical Study on Damage Behavior of CFRP Laminate Subjected to Simulated Lightning Current

The damage induced by lightning strikes in carbon-fiber-reinforced plastic (CFRP) laminates with fasteners is a complex multiphysics coupling process. To clarify the effects of different lightning current components on the induced damage, components C and D were used in simulated lightning strike tests. Ultrasonic C-scans and stereomicroscopy were used to evaluate the damage in the tested specimens. In addition, the electrothermal coupling theory was adopted to model the different effects of the arc and the current flowing through the laminate (hereinafter referred to as the conduction current) on CFRP laminates with fasteners under different lightning current components. Component C, which has a low current amplitude and a long duration, ablated and gasified the fastener and caused less damage to the CFRP laminate. Under component C, the heat produced by the arc played a leading role in damage generation. Component D, which has a high current amplitude and a short duration, caused serious surface and internal damage in the CFRP laminate and little damage to the fastener. Under component D, the damage was mainly caused by the Joule heat generated by the conduction current.

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Numerical Study of Creep Damage Behavior of Thin Film/Substrate Systems under Indentation

Materialwissenschaft und Werkstofftechnik ◽

10.1002/mawe.200400851 ◽

2005 ◽

Vol 36 (2) ◽

pp. 75-79 ◽

Cited By ~ 3

Author(s):

BX. Xu ◽

J.S. Wan ◽

B. Zhao ◽

ZF. Yue

Keyword(s):

Thin Film ◽

Numerical Study ◽

Creep Damage ◽

Damage Behavior ◽

Film Substrate

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Numerical Study of Lightning Protection of Wind Turbine Blade with De-Icing Electrical Heating System

Energies ◽

10.3390/en13030691 ◽

2020 ◽

Vol 13 (3) ◽

pp. 691

Author(s):

Yang Zhao ◽

Xi Wang ◽

Qibin Zhou ◽

Zhenxing Wang ◽

Xiaoyan Bian

Keyword(s):

Wind Turbine ◽

Turbine Blade ◽

Numerical Study ◽

Heating System ◽

Wind Turbine Blade ◽

Electrical Heating ◽

Electromagnetic Transients ◽

Lightning Protection ◽

Lightning Strikes ◽

Lightning Current

In order to solve the problem of icing on the surface of wind turbine blade, a heating system that includes a carbon fiber net (CFN) and power cables is proposed recently. When lightning strikes at the blade with a de-icing heating system, the blade and its heating system are more easily damaged due to the overvoltage between the lightning protection system (LPS) of the blade and the heating system. In this paper, the models of a wind turbine blade with the de-icing heating system are established by Alternative Transients Program/Electromagnetic Transients Program (ATP–EMTP) and the accuracy of models is verified through an experiment. With these models, the influence of lightning current, surge protective devices (SPDs) and earthing resistance of wind turbine are analyzed by calculating the voltage between the down-conductor of the LPS and the heating system. The results show that the voltage is positively correlated with lightning current amplitude and negatively correlated with the front time of lightning current. SPDs are quite useful to reduce the voltage, and an optimal installation scheme of SPDs is obtained by simulation. It is noted that voltage decreases slightly with the increasing earthing resistance with the optimal installation scheme of SPDs.

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Behaviour of RC structures strengthened with prestressed CFRP laminates: a numerical study

IABSE Symposium, Guimarães 2019: Towards a Resilient Built Environment Risk and Asset Management ◽

10.2749/guimaraes.2019.0276 ◽

2019 ◽

Author(s):

José Sena-Cruz ◽

Luís Correia ◽

Paulo França

Keyword(s):

Numerical Study ◽

Shear Stresses ◽

Premature Failure ◽

Rc Structures ◽

Cfrp Laminate ◽

Flexural Strengthening ◽

Cfrp Laminates ◽

Externally Bonded ◽

Fibre Reinforced Polymer ◽

Rc Slabs

<p>The externally bonded reinforcement (EBR) technique is one of the most widely used strategies for the flexural strengthening of reinforced concrete (RC) with fibre reinforced polymer (FRP) materials. The EBR technique offers several structural advantages when the FRP material is prestressed. The development of high shear stresses at the ends of the prestressed FRP material can cause premature FRP peeling-off failure. This premature failure can be delayed or even avoided with the use of special end-anchorage systems, like the mechanical anchorage (MA) system and the gradient anchorage (GA) system. This paper presents an experimental and a numerical study on RC slabs strengthened in flexure with prestressed carbon FRP (CFRP) laminate strips, namely: (i) one reference slab; (ii) one slab strengthened with non- prestressed externally bonded CFRP (EB-CFRP) laminate; (iii, iv) and two slabs strengthened with prestressed EB-CFRP laminates using the MA and GA systems. The performance of these simulations was compared with results of the slabs experimentally tested up to failure. Subsequently, these models were used on a parametric study that intended to investigate the influence of different parameters affecting the behaviour of the slabs strengthened with prestressed EB-CFRP laminates.</p>

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