| The reinforced concrete frame structure is one of the common structural types of highspeed rail station buildings.During the life cycle of the station structure column,it may encounter impacts from accidental loads such as derailed trains,causing serious damage to the reinforced concrete columns,and even the continuous collapse of the entire station structure,causing people’s lives and national property.huge loss.In recent years,the use of carbon fiber reinforced polymer(CFRP)composite materials to improve the impact resistance of structural members has become a research hotspot.In this thesis,the typical reinforced concrete structural columns and carbon fiber reinforced reinforced concrete structural columns commonly used in high-speed railway station buildings are studied.The main research contents and results are as follows:(1)According to the high-speed rail station reinforced concrete structure,train impact point,train impact energy and other factors,five square-section reinforced concrete column test members FH1~FH5 were designed,and FH2 was used as the reference member.CFRP reinforced test component FH2-Z1;impact hammer impact test program was designed.(2)FH1~FH5,FH2-Z1 were subjected to impact test with unequal span(impact point at 2/9L).The experimental results show that:(1)The reinforced concrete test members FH1~FH5 all exhibit shear failure mode;the impact time history curves of each component are composed of level value segment,platform segment and descending segment;with the increase of impact height,impact The peak value of the force increases,but the change of the platform value is not obvious;as the longitudinal reinforcement ratio increases,the impact force platform value increases slightly,and the holding time is shortened;as the ratio of the hoop ratio increases,the platform segment is more stable and fluctuates.Reduced;the axial pressure ratio has a large impact,which makes the platform section shorten rapidly.(2)Compared the corresponding FH2 with FH2-Z1 members wrapping with CFRP reinforced,their failure mode is generally characterized by a bending,the impact force peak is reduced,the platform value is not changed,and the platform segment time is reduced.(3)To further study the affect of CFRP,a finite element model was established.Compared with the experimental results,the verification of the model is verified.By comparing and analyzing the bending moment time history,shear force time history.The analysis results show that during the impact process,the shear force of the critical section(impact point section)of the RC component drops immediately after reaching the peak value,and most of the bearing capacity is forfeit.The section cannot modeling an effective bending moment;the main strain of the reinforced bar is concentrated at the stirrup in the entire component range;The flexural shear strength of CFRP-RC members increases.After reaching the peak,the bending moment and shearing force of the CFRP-RC members are recorded as a high level,and then begin to decrease until the longitudinal bars break.It is further verified that the FH2-Z1 reinforced by CFRP changes from the shear mode of the original FH2 to the bending failure mode.(4)The influence of parameters on the impact performance of FH2 and FH2-Z1 was analyzed by finite element method.The parameters included impact velocity and reinforcement ratio.The results show that the change of impact velocity and longitudinal reinforcement ratio does not change the failure mechanism of the two members.Steel FH2 is shear failure and FH2-Z1 is bending failure;but with the increase of impact velocity and longitudinal reinforcement ratio effectively improve the impact performance of the CFRP-RC member and reduce the deflection of the member. |
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