Numeircal Simulation Study Of Frame Structures Impacted By Debris Flow

Debris flow happened frequently in the western region of China, and it has broughtgreat influence to the destruction of buildings and people’s life.The response of thestructure impacted by debris flow is simulated, and it will lay the foundation for theresearch of building impacted by debris flow.The interaction between debris flow andstructure is analyzed by coupling Numerical Solutions theory and finite elementnumerical simulation software.The thesis is divided into five chapters. Specific studiesare as follows:(1)The purpose and significance of paper, researh status and results of fluid-solidcoupling in China and abroad are described. Numerical technology of fluid-solidCoupling, the problem of numerical simulation,and main question discussed in thispaper are introduced.(2)Continuity equation and momentum conservation equations are established todescribe viscous debris flows based on viscous Fluid Dynamics and RheologicalBehavior of viscous debris flows. Density, flow velocity, and impact force of debrisflow are presented.(3)Debris flow and structure coupling solving process is introduced in the fluiddomain, structural domain, grid update technology and coupling interface data transfer.The fluid domain is solved by using a time discretization CBS algorithm, andcalculated tetrahedral element meshing is used. The viscous incompressible fluidequations is written to finite element scheme under ALE description, and the arbitraryEuler-Lagrange dynamic mesh technology is introduced; Structural dynamics equationare given under fluid-structure interaction in structural domain, and is solved by thedirect integration method; Virtual elastic methods is used in grid update technology;Not match grid is used in interface data transmission.(4)The ideal time and force impact curve is obtained by simplified the debris flowoverall impact to the rectangular load and simplified impact of the stones to atriangular load, and is imposed on a two-story frame structure through the fourconditions. The displacement and stress changes of column is got by using finiteelement software. the maximum displacement of the structure is deduced, and bycompared between structure’s theory maximal displacement and simulation maximaldisplacement, the limitation of the maximum displacement is obtained. It can provide adesign reference for building impacted by debris flow.(5)The three-dimensional model of the entire domain is established by CADsoftware,and is imported Ansysworkbench to coupled simulation. Viscous debris flow field is simulated in the CFX to get the size and distribution of velocity andpressure field. Through Passed the coupling interface loads, debris flow pressure fieldis exerted to the structural domain, and finally displacement and stress of structure isobtained.