Mechanical Response Of Concrete Gravity Dam Under Strong Impact Loading

In today's world,the problem of resource and environment has become increasingly serious.So the development and utilization of water resource become an important task.As the main body of water resource engineering facilities,the dams were built around the world.When the dam provided clean energy for the development of national economy,it also became the focus in terrorist threats and local wars.Once the dam engineering was attacked,the loss of state and people couldn't be estimated.So studying the dam mechanical response under strong impact load has very important strategic significance.Because of this,the mechanical response of concrete gravity dams under the strong shock was researched systematically.Many data for damage assessment,safety protection and the design of the dam body optimization would be provided.The research works were as follows:(1)The finite element model of concrete gravity dam under penetration and explosion loading was analyzed.Constitutive models of concrete material,projectile material,explosive,water and air were acquainted.Then,numerical model of kinetic energy projectile penetrated concrete gravity dam was established by the mature LS-DYNA finite element software.The influence of projectile velocity and different angles of projectile penetration on penetration destroy were discovered.The results showed that the greater projectile velocity,the deeper penetration depth,the larger open pit.The greater penetration angles,the greater penetration depth affected,and even ricochet phenomena might occur.(2)Based on the results of penetration,the fluid-solid coupling model for dynamite explosion in the dam body was established.The stress condition was returned to that after penetration through restart.The mechanical response of concrete gravity dam under penetration and explosion loading was discovered.The result showed that projectile penetration destruction concentrated in the vicinity of the ballistic,while the explosion process caused extensive damage.(3)The influencing factors of underwater explosion were analyzed.Based on this,the fluid-solid coupling model of underwater explosion was set up.The influence of different explosion position,different charge,detonation pitch and different medium were studied.(4)The cavitation phenomenon of high-speed projectile entering water was understood.The fluid-structure coupling model of high-speed projectile entering water was set up to research the process of high-speed projectile entering water.What was more,the underwater projectile penetration was researched.The morphology of water and air in thewhole process was paid attention to.The damage of projectile underwater and air penetration was contrasted.