A Comparative Study on Damage Mechanism of Sandwich Structures with Different Core Materials under Lightning Strikes

Abstract

Wind turbine blades are easily struck by lightning, a phenomenon that has attracted more and more attention in recent years. On this subject a large current experiment was conducted on three typical blade sandwich structures to simulate the natural lightning-induced arc effects. The resulting damage to different composite materials has been compared: polyvinyl chloride (PVC) and polyethylene terephthalate (PET) suffered pyrolysis and cracks inside, while the damage to balsa wood was fibers breaking off and large delamination between it and the resin layer, and only a little chemical pyrolysis. To analyze the damage mechanism on sandwich structures of different materials, a finite element method (FEM) model to calculate the temperature and pressure distribution was built, taking into consideration heat transfer and flow expansion due to impulse currents. According to the simulation results, PVC had the most severe temperature and pressure distribution, while PET and balsa wood were in the better condition after the experiments. The temperature distribution results explained clearly why balsa wood suffered much less chemical pyrolysis than PVC. Since balsa wood had better thermal stability than PET, the pyrolysis area of PET was obviously larger than that of balsa wood too. Increasing the volume fraction of solid components of porous materials can efficiently decrease the heat transfer velocity in porous materials. Permeability didn't influence that much. The findings provide support for optimum material selection and design in blade manufacturing.

Estimation of the Compressive Strength of Corrugated Cardboard Boxes with Various Openings

“…Thus, there is a need of using models, which are simplification of the real objects without losing adequacy to reality. In the numerical analysis of layered materials [17][18][19] and constructions, made from such materials, it is useful to perform a process called homogenization [20,21]. As a consequence, instead of structure of layers made from different materials one can obtain one layer characterized by effective properties of the composite.…”

A Comprehensive Analysis of Wind Turbine Blade Damage

“…Damage from lightning to wind turbine blades strongly depends on the structural materials. According to relevant experiments, polyvinyl chloride (PVC) and polyethylene terephthalate (PET) suffered pyrolysis and cracks inside when tested under severe temperature and increasing pressure strikes, while in cases of balsa wood blades, fibre breakage and large areas of delamination between the wooden material and the resin layer have been observed [37].…”

Optimal Design of a Fiber-Reinforced Plastic Composite Sandwich Structure for the Base Plate of Aircraft Pallets In Order to Reduce Weight

“…Peliński and Smardzewski determined the effect of thickness and type of wood-based facings on stiffness, strength, ability to absorb, and dissipate the energy of sandwich beams with an auxetic core [ 21 ]. Yan et al conducted a large experiment on three typical blade sandwich structures to simulate the natural lightning-induced arc effects [ 22 ]. Abada and Ibrahim investigated numerically the effectiveness of using ribbon shapes as an innovative core for sandwich structures subjected to blast loading [ 23 ].…”