| In recent years,all kinds of terrorist attacks all over the world continue to occur,among which,the explosion terrorist attacks caused the most serious harm,and the incidence of various explosion accidents increased year by year,causing serious damage to various building facilities.As an important part of building facilities,reinforced concrete beams and slab members are of great significance in considering the dynamic response of reinforced concrete beams and slab members under the action of explosive loads.Due to the unique mechanical properties,good adhesion,heat resistance and corrosion resistance of carbon fiber composite(Carbon Fiber Reinforced Polymer),etc.It can be widely used in the strengthening of civil engineering structures.In this paper,the dynamic response of reinforced concrete T-beam strengthened by CFRP under explosion is studied,and the parametric analysis is carried out.The main research work is as follows.1.This paper analyzes the research status of dynamic response of beam-plate members under explosion load at home and abroad,and it lays a foundation for theoretical research by studying the basic phenomena of explosion,explosion shock wave and structural anti-explosion design.2.The explosion process of TNT explosive in free air was numerically simulated by ANSYS/LS-DYNA.The numerical simulation results and the calculation results of various empirical formulas were compared to verify the accuracy of the parameters of the numerical model in this paper.3.The separation model of reinforced concrete T-beam-CFRP material-air domain-TNT explosive is established by using ANSYS/LS-DYNA finite element software.The numerical simulation of T-beam under explosive load is carried out,and its mechanical properties are analyzed.including the equivalent stress of concrete,first principal stress,pressure,displacement,steel skeleton displacement and equivalent stress and first principal stress of CFRP material.4.Considering the influence of different parameters on the dynamic response of reinforced concrete T-beam strengthened by CFRP,this paper mainly analyzes the external attachment form of CFRP,the thickness of CFRP and the explosive equivalent.The effect of TNT on the anti-explosion performance of reinforced concrete T-beam strengthened by CFRP with different horizontal distance and vertical distance relative to the middle span.The results show that the most favorable reinforcement method for reinforced concrete T-beam is that the thickness of CFRP reinforcement is 0.3mm when the top and bottom of the T-beam are bonded with CFRP;at the same time.With the increase of explosive content,the peak displacement of the beam increases gradually.When 1640 g explosive quantity is detonated,the beam changes due to its tension and bending.The shape is destroyed.When the explosive content is more than 1640 g,the beam is destroyed due to bending and shear deformation,so the reasonable explosive quantity is 1640 g.For the horizontal blasting distance,with the increase of the horizontal blasting distance,the displacement peak value of the middle node of the beam span decreases gradually,and the influence of the explosion wave on the displacement of the mid-span node decreases gradually.The velocity of beam mid-span joint changes more and more with the increase of horizontal explosion distance between beam span and beam span.For the vertical blasting distance,with the increase of the vertical distance,the amplitude of the displacement change of the node at the middle and bottom of the span becomes larger.When the vertical explosion distance is 70 cm,the velocity reaches the maximum value,and the vertical explosion distance is obtained.The maximum damage degree of T beam is 70 cm. |
PDF Full Text Request