Prediction procedure for hail impact

Simon Dousset,Augustin Gakwaya,Frédéric Dau,Jérémie Girardot,E Buzaud,E Cadoni,H Couque,A Cosculluela

doi:10.1051/epjconf/201818301046

Abstract

The constant increase of composite materials’ performances makes them more and more used in recent aircrafts. Structures, as the wings or the fuselage, may suffer from hail impacts that can make critical damages or even perforate them. In order to guaranty the safety of passengers, aircrafts have to be certified and simulations have to demonstrate good agreements with real behaviour of the structures and the hail projectile. The aim of this work is to propose a procedure to analyse the home made manufacturing of the ice generally performed in laboratories, its mechanical characterization and a mechanical model that can predict the time-space profile of the impact force on a rigid structure. Because of the high strain level of the hail during the impact, the Smooth Particle Hydrodynamics (SPH) method will be used. Indeed, the finite elements method needs heavy remeshing that are time consuming to avoid mesh distortion. The SPH is a numerical meshless method that calculates interactions between particles at every time increment. Models available in the literature have been studied and the model of J.D. Tippmann (Tippmann, Kim, et Jennifer D. Rhymer 2013) is chosen. In this paper, the Tippman model is presented with its solving using the SPH. A parametric study is proposed in order to catch the relevant parts of this model. A simple experimental procedure is then proposed to feed the model and the results of impact simulations at different velocities are compared to experimental measurements realized in the laboratory.

Highlights

1.1 Types of ice Studies of hail impact were mostly experimental and tried to understand the constitutive ice material.Ice can be found in nature with many different microstructures
Four types of ice are mainly manufactured in laboratories: accretion ice, compacted snow, perfect moulded ice and moulded ice with defects [3,4]
The main purpose of this study is to present the first results on the development of a complete detailed procedure to realise simulations of hailstone impact:

Summary

Introduction

1.1 Types of ice Studies of hail impact were mostly experimental and tried to understand the constitutive ice material.Ice can be found in nature with many different microstructures. 1.1 Types of ice Studies of hail impact were mostly experimental and tried to understand the constitutive ice material. The one that is most common is the polycrystalline ice [1,2], because found on earth at atmospheric pressure conditions. Four types of ice are mainly manufactured in laboratories: accretion ice, compacted snow, perfect moulded ice and moulded ice with defects [3,4]. Laboratories study one type or another depending on their objectives and manufacturing process available. The ice’s behaviour depends on the temperature [1], [5]. It has been chosen to study hailstones impact at -10 °C, a temperature mostly chosen in the literature because near the conditions of the worst case that structures can encounter [6]

Objectives

Results

Conclusion