Analysis And Research On Seismic Performance Of Carbon Nanotube Concrete Bridge Piers Based On ABAQUS

Since the 21st century,my country’s economy has achieved rapid development.Bridges have always played a very important role as an important transportation structure for economic development.To adapt to rapid economic development,my country’s bridge construction has entered a stage of rapid development,and bridges are also developing in the direction of high difficulty and high requirements such as crossing rivers and seas,such as the Hong Kong-Zhuhai-Macao Bridge.But at the same time,our country is located at the junction of the Asia-Europe plate and the Pacific plate.It is an earthquake-prone area.Once an earthquake is encountered in many economically developed areas,the loss is often more serious than the earthquake itself.Bridges are lifeline projects,if they are caused by earthquakes.The damage makes it difficult to carry out subsequent rescue and reconstruction work.Therefore,research on their seismic performance is very important.The pier is the most important part of the bridge structure.Traditional reinforced concrete piers can no longer meet our seismic requirements for bridge structures.Carbon nanotubes(CNT)are a new type of nanofiber material with light weight,high strength and ductility.The good feature is that it is added as a fiber material to concrete materials to make carbon nanotube concrete,which is superior to ordinary concrete in all aspects.At present,the application of carbon nanotube concrete to bridge piers,there are few studies on the seismic performance of bridge piers.This paper will use ABAQUS finite element analysis software to study the stress-strain relationship of carbon nanotube concrete,and establish carbon nanotube concrete bridge piers to study the seismic performance of carbon nanotube concrete bridge piers,mainly including the following:(1)By studying the structural characteristics of carbon nanotube concrete,selecting concrete damage theory for analysis,and on this basis,put forward a concrete elastoplastic damage constitutive model that is most suitable for the changing characteristics of concrete force action,and put forward the finite element analysis of carbon nanotube concrete in this paper.method.(2)Combining the concept of representing a volume unit and using the equivalent continuum model theory of molecular structural mechanics,the carbon nanotubes are equivalent to a cylinder,and on this basis,a representative volume unit of carbon nanotube concrete is established.In the axial tension and compression test,the constitutive relationship of the carbon nanotube concrete was finally obtained and the relationship formula was proposed.(3)Use the obtained constitutive relationship of carbon nanotube concrete to simulate the flexural test of carbon nanotube concrete,and verify the rationality of the constitutive relationship with actual test data.It was found that the flexural strength of the carbon nanotube concrete obtained by the simulation was 5.13 MPa,and the error between the flexural strength of the carbon nanotube concrete obtained by the actual test and 5.35 MPa was 4.1%.It is within the allowable error range,indicating that the simulated carbon The constitutive relationship of nanotube concrete is reasonable,which also provides conditions for the study of carbon nanotube concrete bridge piers in this paper.(4)Hysteresis curves,skeleton curves,and displacement ductile coefficients are analyzed by low-cycle repetitive motion simulation of carbon nanotube concrete piers and compared with ordinary concrete piers.It turns out that under the same load,the area surrounded by the hysteresis loop of the carbon nanotube concrete bridge pier is larger than that of normal concrete,the ultimate bearing capacity is increased by 7.3%,the displacement ductility coefficient is 11.5%.It shows that carbon nanotube concrete has better seismic performance.(5)Through dynamic time history analysis of carbon nanotube concrete bridge piers,the response of carbon nanotube concrete bridge pier tops under the action of three kinds of seismic waves is analyzed,and the time history curves of the relative peak displacement and rotation angle of the pier tops are drawn,and it is found that under the action of Taft waves Compared with ordinary concrete,the relative peak displacement of the carbon nanotube concrete pier top is reduced by 64%,and the maximum rotation angle of the pier top is reduced by 3.6%,indicating that the carbon nanotube concrete pier has a pier top displacement and pier top displacement under the action of earthquake.The top corner is smaller,which is more conducive to the seismic resistance of the structure.(6)The conclusions obtained in this paper are summarized,and the analysis results of the seismic performance of carbon nanotube concrete bridge piers are obtained.At the same time,some suggestions are put forward for the weak links in the research process of this paper,and the prospects for the application of carbon nanotube concrete in other aspects are put forward.