Research On The Characterization Of Structural Explosion Based On SPH-FEM Coupling Method

Explosion involving material damage and large deformation and other issues,in addressing such a strong impact on large deformation problems,however,deficiencies in theory and experiment limit the research and exploration of explosion problem.With the development of computer technology and numerical methods,numerical methods have been widely used in the study of the explosion problem,which has a very important reference value for engineering application.The development of the Finite Element Method(FEM)is very mature,and it has good calculation accuracy and efficiency for small deformation problems,but its accuracy and efficiency decrease significantly due to the element distortion when it is used for problems involving large deformations and material fracture.Smoothed Particle Hydrodynamics(SPH)has a big advantage in dealing with large deformation problems,it has strong ability in modeling large deformations and is easy to simulate material fragmentation and splash,but its calculation accuracy and efficiency in lower distortion regions is not as good as FEM.For the explosion problem,the large deformation only occurred in the local area,so SPH-FEM coupling method will be used to solve the explosion problem,which can make use of the advantages of the two methods.The large deformation regions are solved with SPH,and the other regions are solved with FEM.By doing so,not only the accuracy of large deformation region can be improved,but also good efficiency can be obtained.First of all,this paper described the progress of explosion and composite structure problem,SPH-FEM coupling method will be used to solve the explosion problem.The details of SPH?SPH-FEM and composite were also introduced.The finite element model for analyzing impact damage of composite laminates was established.By adopting this model,the dynamic response and damage propagation of laminates were studied.Secondly,the model for analyzing vehicle's pyroshock was established base on SPH-FEM coupling method,the coupled SPH-FEM method employs SPH particles in the higher distortion regions for explosion bolt and finite elements for vehicle's separate structure.The characterization of vehicle's pyroshock is studied by SPH-FEM coupling method,the numerical results well agree with the experimental results and thus verify the accuracy of the model.Thirdly,according to the structural design and detonative way of explosive bolts,the influence of the order of bolt initiation sequence and initiation interval were studied to seek measures to reduce the explosive impact environment.The main analysis results show that explosion bolts detonate in a certain order and interval,which can effectively alleviate the explosive impact to the separate structure.Fourthly,the structural design of composite laminate were taked into account to study the characterization of vehicle's pyroshock.Parametric studies were conducted to study the effects of the material strength parameters and stacking sequence on the dynamic response of vehicle structure under explosion impact,which aims at providing references for the explosion shock resistant of the vehicle structure.