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• CFRP/PMI sandwich panels were experimentally studied under ice projectile impact with different incident angles and impact velocities. • The impact force of the ice projectile and the peak deformation of the target plate correlate with the ice projectile's normal velocity. • The energy absorption of the foam layer shows a quadratic positive correlation with the normal velocity of the ice projectile. The integration of composite sandwich structures in aircraft design necessitates consideration of hail impacts within aerospace applications. This investigates the dynamic response and damage characteristics of a carbon fibre/PMI foam sandwich structure under hail impact through both experimental and numerical simulation methods. These methods analyse the impact velocity, fibre panel thickness, and angle of incidence of the ice projectiles. The study establishes relationships among various parameters such as ice projectile impact force, foam absorption energy, and target plate deformation in relation to the impact velocity and angle of incidence. The damage sustained by the carbon fibre/PMI foam sandwich (CPS) structure due to ice projectile impact was systematically categorized and examined. Additionally, the effects of normal and tangential impact velocities on the target plate's dynamic response during oblique impacts were investigated. This research serves as a valuable reference for understanding the dynamic response and damage characteristics of composite foam sandwich structures subjected to ice projectile impacts, With a focus on the carbon fibre/PMI foam sandwich structure. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fibre metal laminates based on basalt fibres have been manufactured and their response to low velocity impacts assessed. • Impactor shape and impact energy significantly affected the impact response of hybrid laminates. • Damage modes and energy absorption rules were obtained under different impact condition. Due to their excellent impact resistance, fibre-metal laminates are widely utilised in modern engineering industries such as the construction of aircraft, vehicles and ships. In this study, the low-velocity impact characteristics of basalt fibre/steel hybrid laminates with different lay-up structures were studied with a drop hammer. This was done through a series of low-velocity impact experiments with different hammer head shapes and impact energies. It can be seen from the results that the impact behaviour of hybrid laminates largely depends on the shape of the hammer head, impact energy and lay-up structure. The sharper the hammer head, the smaller the peak impact load and the greater the displacement. When the hammer head penetrates the laminate, apparent shear failure occurs under the impact of the flat hammer head. Petal-like fractures caused by tensile tear failure occur under the impact of the hemispherical and conical hammer head. Low-energy impacts may result in large plastic deformation, delamination and debonding in the layers. High-energy impacts may also lead to fibre and metal fractures as well as perforation damage. Consequently, the laminate absorbs the energy from overall deformation under low-energy impact, but mainly absorbs the energy generated by various fibre and metal fractures under high-energy impact. [ABSTRACT FROM AUTHOR]

• A modified split Hopkinson bar is developed for sub-zero temperature testing. • Dynamic fracture toughness of freshwater ice is measured. • Fracture toughness of ice are studied by notched semi-circular bend method. • Factors affecting the dynamic fracture toughness of freshwater ice are determined. • The failure mode of freshwater ice is evaluated at different loading rates. The dynamic fracture toughness of ice involves its fracture resistance under impact loading, which is essential for impact or blasting parameter selection and evaluation. Temperature is an important factor influencing ice mechanical properties. To examine the evolution of ice fracture characteristics at different loading rates and temperatures, notched semi-circular bend method was applied to determine the freshwater ice quasi-static and dynamic fracture toughness. A modified low-temperature split Hopkinson pressure bar system was developed to measure dynamic ice fracturing properties. A high-speed camera captured ice specimen cracking initiation and propagation processes. The experimental results indicate that the overall initiation fracture toughness (IFT) of freshwater ice under dynamic loading exceeds that under quasi-static loading. The loading rate effect on the dynamic fracture toughness and failure modes greatly exceeds the test temperature effect. The freshwater ice dynamic IFT increases approximately linearly with the loading rate and rapidly at temperatures from –5°C to –45 °C. In all tests, cracks always initiate from the notch plane. Two symmetrical curved cracks then propagate from the contact end of two support rollers to the flat contact end, ultimately leading to different sample fragmentation distributions. These results improve the understanding of the dynamic fracturing mechanism in ice engineering applications. [ABSTRACT FROM AUTHOR]