Research On The Failure Mode Of The Concrete Gravity Dam Under Blast Loading Based On FEM/SPH Coupling Method

With the development of Hydropower Engineering technology, endless highdams emerge in our country. Because of the precise attack operation in the modernwar, the dam which has the unique political, economic and military value undoubtedlywill become wartime target, which will bring great disaster and loss to the localpeople and causes social impact, the consequences could be disastrous. Therefore it isvery significant to conduct the investigation on anti-explosion performance of thedam underwater explosion, so as to take rational measures to protect the dam.Arbitrary Lagranian-Eulerian(ALE) method, smoothed particlehydrodynamics(SPH) method and coupling method(FEM/SPH) were adopted fornumerical simulation of underwater blasting, compared the advantages anddisadvantages of three methods through the results. The traditional simulation basedon mesh has much defect in applying in underwater explosion such as largedeformation which will lead to calculation interruption. While, the smoothed particlehydrodynamics(SPH) method is a numerical simulation based on meshfree, particleand Lagrangian nature, which avoids mesh deformation and is very suitable to solveexplosion problem, but it is very computa-tionally expensive. The coupling ofsmoothed particle hydrodynamics(SPH) with the finite element method(FEM) ispresented to make full use of the superiority of SPH in dealing with large deformationand the high accuracy of FEM.In the condition of underwater blasting shock load, the response and failuremode of dam were the key problems in evaluating the dam of antiknock safety. Inthis paper, based on nonlinear finite element, gravity dam fully coupled model wasbuilt by using soft ware AUTODYN. Underwater explosion was simulated byincorporation of the SPH algorithm into finite element method, and where the SPHnodes were employed to model the area with large deformation, FEM nodes wereemployed to model the area with small deformation. This could provide the keyfactors influencing the response and failure mode of dam. The study show that, theresponse and failure mode of dam was influenced by the different underwater depth,the blast center distance and the bomb dosage. The regularities of dam typical particleshaking, the formation and development of the response and failure mode of dam wasstudied. The result showed that the contact explosion could causes destruction to dam,the head of a gravity dam is one of the weak parks for antiknock performance, the head maybe lead to topple because of the lower structure damaged seriously, whichmay cause dam break.This thesis conclude some results with certain engineering value, which can beused into the protective design of dam in the future.