An experimental technique for the evaluation of properties of ice

Abstract

The problem of ice accretion and accumulation on critical structural components of fixed wing and rotary wing aircraft structures has in recent years engendered much interest. However, the mechanical properties of the accreted impact ices are at present not adequately known and, therefore, analytical modeling of this particular material is not possible. This paper proposes a technique for experimentally determining both the modulus of elasticity and tensile strength of ice. The feasibility and accuracy of the test technique were verified by determining the properties of laboratory grown ice. Results reveal a slight degradation of ice tensile strength with an increase in test temperature. The degradation in ice tensile strength is rationalized on the basis of competing mechanistic effects involving an incipient melting of the ice at the higher test temperature and a concomitant intrinsic variation in microstructural features due to variations in freezing rate. Application of the test technique to impact ices will soon be conducted inside an icing wing tunnel.