Impact Resistance And Structural Optimization Of Polyurea-coated Aluminum Sheet

In recent years,polyurea elastomeric materials have received widespread attention because of their expedient application techniques,excellent adhesive characteristics and excellent physical property.The results of domestic and international studies have shown that polyurea coatings can be used to improve the impact resistance of structural members by forming composite structures with aluminum plates,steel plates,masonry walls,etc.However,the existing research is limited to the impact protection effect of polyurea coating on aluminum flat plate structure,and the impact response study of aluminum curved plate structure with different curvature of polyurea coating has not been reported.Therefore,it is necessary to study the impact protection effect of polyurea elastomeric materials for curved aluminum panels in engineering buildings.In this paper,based on the existing studies,the impact performance study of polyurea coated aluminum curved plate and the impact resistance study after the optimization of different curvature structures are carried out to clarify the effect and mechanism of polyurea coating action and the optimal structural form of polyurea coated aluminum thin plate,which provides reasonable guidance for the application of polyurea coating in the design stage and later reinforcement stage of composite structure in engineering.Based on this,The main contents of this paper and the related results are as follows:(1)The finite element model of composite structure composed of aluminum plate,polyurea and aluminum plate was established by numerical simulation research method,and the final simulation results were compared with the experimental results of literature research on the basis of grid sensitivity verification,and the error was within 10% to verify the accuracy and reliability of the low-speed impact model of composite polyurea-aluminum plate structure.(2)Through numerical simulation research,the impact resistance of pure aluminum plate structure and its polyurea coated aluminum thin plate structure after polyurea coating was studied from the aspects of deformation analysis,impact load and energy absorption analysis,and the final results showed that the addition of polyurea layer improved the impact resistance of metal aluminum thin target plate from the aspects of deformation,impact load or energy absorption.The double-sided coated polyurea target plate was the most obvious,and the residual deformation,impact load and maximum energy absorption values were14.22 mm,12.79 k N and 419.79 J,respectively.(3)Since the optimization of target plate structure is required in this paper,the impact resistance of polyurea coated thin aluminum plate structure is influenced by the thickness of polyurea layer and the coating position,and it is found that the addition of polyurea layer can reduce the deformation of the metal plate compared with the pure aluminum plate,no matter the polyurea is coated on the spring side,back side or both sides,and the best effect of polyurea coating on both sides is also found in the thickness range of this simulation.The impact resistance of polyurea coated structure will be improved with the increase of polyurea layer thickness.However,when the coating thickness changed from 4mm to 5mm,the deformation energy per unit center of the optimal type double-sided coated polyurea target plate increased from 29.76J/mm to 29.82J/mm,and the impact resistance of the polyurea layer for each coating type target was no longer significant.(4)According to the analysis of the impact resistance of polyurea coated aluminum thin plate,the finite element model of polyurea coated curved aluminum sheet under different curvatures was established,and the structural optimization form of polyurea coated aluminum sheet structure with different curvature was comprehensively analyzed.From the perspective of coating type,the structure of curved target plate and the structure of planar target plate are similar,and the impact resistance of polyurea coated on the double-sided structure of the target substrate will be better than that of polyurea coated single-sided(face surface and back bullet surface)target plate,on this basis,the application suggestions of impact protection and structural optimization design of polyurea coated aluminum sheet are proposed,which provides more reference and basis for future engineering applications and structural optimization.