Experiments And Simulations Of Ice Mechanics Property And Impacting Behavior

As a solid phase of water,ice has brought many problems to the related engineering fields such as aviation,ships,bridges,etc.The mechanics properties of ice are one key base of the industrial technology,for instance,the protecting aircraft against the impact by hail and the dynamic problems of icebreakers are particularly prominent.At present,most of the research on ice is mainly focused on the compressive properties,but the research on the tensile strength of ice is relatively lacking.In response to this kind of problem,in addition to studying the dynamic and the static compressive properties of artificial freshwater ice,this paper also conducts the the dynamic and the static split tests of them to test the dynamic and the static split strength of ice at different temperatures and different strain rates.At the same time,in view of the problem of hail disaster,experiments and numerical simulations of composite laminates with ice ball impact were carried out to study the mechanical response of laminates under highspeed impact loads of the hail.The main contents and conclusions are as follows:(1)The preparation process of ice sample was studied,and the ice sample without bubbles was prepared,and a universal test machine was used to perform quasi-static compression,Brazilian disc,and ice ball split experiments on artificial freshwater ice samples in the temperature range of-5 to-55 ° C.The results show that the compressive and the split strength changes significantly with temperature,and the strength increases with decreasing temperature between-5 and-35 ℃,when the temperature is lower than-35 ℃,the strength will decrease with the decrease of temperature;(2)Using SHPB,dynamic compression,Brazilian discs,and ball impact tests of-15 ° C,-35 ° C,and-55 ° C,were performed on the ice samples of the same size.It is concluded that the dynamic compression and the split strength of ice are both greater than the compression and the split strength under quasi-static loading,showing a clear rate correlation.And it is found that the change trend of compressive and split strength with temperature under high strain rate is different from that exhibited under low strain rate,at high strain,both the compression and the split strength increase with decreasing temperature,and there is no maximum at-35 ℃.At the same time,the crack growth of the sample was recorded with the help of a high-speed camera,and the failure mode of the center crack of the Brazilian disc and ice ball split test sample was verified.(3)Experiments were performed on 50.8mm and 25.4mm diameter ice balls impacting glass fiber laminates at the different speeds.The support reaction force and the back plate strain are obtained,and it is found that the support reaction force is basically proportional to the impact energy.At the same time,the high-speed camera was used to record the moment when the ice ball hitting the target board,the damage of ice spheres and the deformation of laminated plates at the moment of impact is observed.(4)Totally 11 numerical simulations were carried out,including the different ice ball impact energies,the different lamination methods of laminates,the different impact angles of ice ball,and the different ice ball sizes under the same impact energy.The responses are obtained,summarized and analyzed,in view of the maximum displacement,the energy absorption rate and the equivalent stress of the impact of the backing of the laminate under different working conditions.