Numerical Study On Dynamic Response Of Underwater Explosion To Gravity Dam Strengthened With CFRP

In recent years,China has vigorously developed water conservancy and hydropower projects.As the basic industry of our national economy and social development,water conservancy should arouse enough attention.Against such a backdrop,we have managed to harness rivers in various parts of the country,make use of hydropower to generate electricity,rationally allocate water resources,and build a large number of water conservancy projects and buildings,which have brought rich economic benefits and long-term social impact to our country and people.As a common water conservancy construction structure in China,concrete gravity dam has become an important means and technology to launch missiles to strike accurately in modern wars.Once the war is triggered,the dam will be the first target to be attacked.The safety of the dam directly affects the downstream industrial and agricultural production and the safety of people’s lives and property.Underwater blasting has attracted more and more attention,so it is of great significance to study the dynamic effect and protective measures of gravity dam under underwater explosion impact.Carbon fiber composite(CFRP)is a popular material in recent years.The material itself has good mechanical properties,good adhesion and corrosion resistance and so on.It is used for strengthening geo-structure.In this paper,the dynamic effect of the concrete gravity dam under the impact load of underwater explosion is studied.The main work is as follows:(1)The dynamic effect of gravity dam under underwater explosion load is studied.Based on ANSYS/LS-DYNA finite element software,the fluid-structure coupling algorithm is used,and the strain rate effect is considered to establish a fully coupled model of air,water,explosives,dam and foundation.Numerical simulation of underwater explosion is carried out to analyze mechanical properties,including equivalent stress,first principal stress,displacement,etc.(2)The influence of different parameters on the dynamic effect of concrete gravity dam is considered,including the reinforcement effect and thickness of CFRP material,and the influence of the weight and location of TNT explosive,including horizontal explosion distance and vertical explosion distance,on the anti-explosion performance of CFRP reinforced gravity dam.Through the above numerical simulation and result analysis,it is concluded that when the explosion occurs in the underwater medium,in addition to the explosive yield,we should also pay attention to the effect of the horizontal and vertical distance of the explosive on the impact load of the explosion.In order to protect the gravity dam,the dam head and the weak position should be protected.CFRP material can effectively reduce the damage effect of blast wave on gravity dam,and the reasonable thickness of CFRP should be selected when strengthening the weak position.