Bending Test Of Ice Beam And Analysis Of Mechanic Performance Of Ice Shell

Ice and snow construction materials have the unique advantages of easy use of local materials,environmentally friendly and sustainable,as well as aesthetic effects,which have great application potential in cold regions.However,its low strength and traditional structure construction method greatly limit the height,span and form of the ice and snow structure.The mechanical properties of the ice material can be significantly improved by adding certain reinforcing fiber to the pure ice to form composite ice material.However,there are few researches on the basic mechanical properties of composite ice materials.There is a lack of research on the destructive forms,failure mechanism and bearing capacity of composite ice materials under the action of bending.Pure ice beam and composite ice beam are research objects in this paper.Through computer controlled hydraulic loading system and in-situ four-point bending loading test of ice beam,the failure mechanism of ice beam under the action of bending is studied,and the influence of different influencing factors on the bearing capacity of ice beam is discussed which lays a foundation for the establishment of structural design theory of composite ice.In view of the above research backgrounds,the following researches are mainly carried out:(1)The four-point bending load test of ice beam is designed and completed.Combined with the previous test results of pure ice beam,the va lidity and rationality of the research method are verified,and the relevant test standards for bending loading test of ice materials are supplemented.(2)The influences of different temperature,proportion of reinforcing fiber,shear span ratio and pouring methods on the bearing capacity of composite ice beam are compared.The changes of elastic modulus of composite ice beams at different temperatures,the curve characteristics of load displacement curve of composite ice beams with different fiber mixing ratios,the destructive forms of composite ice beams with different shear span ratios,and the bearing capacity of composite ice beams with layered freezing in different loading directions are analyzed.(3)Combined with the results of computer controlled hydraulic loading system and in-situ four-point bending loading test,the bending failure mechanism of pure Ice beams and composite ice beams is discussed.With the continuous increase of applied load,the failure process of composite ice beam goes through linear section,crack extension section and failure section,and the "pulling" effect of reinforcement fiber on ice material becomes prominent.(4)Two composite ice shell structures constructed at the beginning of 2018 were checked by using the material data obtained from the bending loading of composite ice beams,which is to determine whether the structure exceeded the limit under the action of structural gravity.The displacement and deformation of the structure at different temperatures and the stress response at different thicknesses are discussed.