Numerical modeling of seismic influence on underwater composite oil pipeline

The problem of numerical modeling of the process of seismic activity initiation on an ocean shelf and its destructive effect on composite oil pipelines laid along the seabed is considered. To describe the dynamic behavior of the medium, the determining systems of equations of the theory of elasticity and acoustics are used, with explicit separation of all layers. The composite is described as an orthotropic material. An algorithm is proposed that allows the estimation of volume and type of oil pipeline destruction for a given level of seismic activity and strength characteristics of a composite. A distinctive feature of the developed approach is the splitting of the problem into two stages that are calculated in different scales: the full wave calculation of the propagation of seismic waves from the source of the earthquake to the day surface and the calculation of a composite pipeline element as an anisotropic material of complex shape. For numerical calculation, a gridcharacteristic method is used for hexahedral and tetrahedral computational grids.