Generating Composite Material Maps from Numerical Simulation of Hailstone Impact

Abstract

AbstractOver the lifetime of a wind turbine, the blades receive significant erosion to the leading edge caused by precipitation, leading to large losses in aerodynamic performance and therefore power output. It is therefore prudent to study the mechanics of the erosion process in order to predict and mitigate these losses. Whilst leading edge erosion due to raindrop impact has received much research attention in recent years, very little research has focussed the role of hailstone impact in erosion in wind turbine blades. This paper aims to use a computational simulation model to investigate and characterise the physics of the impact of a hailstone on a flat plate of composite glass fibre material typical of those used in the construction of wind turbine blades. This was achieved by modelling the ice projectile using a Single-Particle Hydrodynamic approach in the software package LS-DYNA. This simulation was used to determine how the impact response in the target plate was affected by various parameters of the impact scenario. Simulations were run using diameters of hailstone between 5 and 20 mm, impact speeds between 80 and 120 ms−1, and at angles of incidence between 90 and 0 degrees. The paper presents these observations in the form of “maps” of the material response at each angle of incidence. It was observed that whilst at low velocities, the material response varies linearly with diameter and velocity and at higher velocities, more complicated behaviour arises due to the interaction between the initial stress wave and the remainder of the impacting projectile.