Session: 04-03-02 Rigid Pipelines II

Paper Number: 80657

80657 - Numerical Simulation of a Subsea Pipeline Subjected to Near-Field Underwater Explosion Loads With the Coupled Eulerian-Lagrangian (CEL) Method 

 

The underwater unexploded ordnance (UXO) may present a potential thread to the subsea structures. It is a complicated physical phenomenon as it involves the interactions among water, seabed, the structure, and the explosive ordnance. Numerical simulations have been used to do the calculation, but normally with an assumption of free explosion space. The seabed effects are simply considered by exaggerating the explosive weight with an empirical factor. This paper tries to include the real seabed effects in such events by using the Coupled Eulerian-Lagrangian (CEL) method. The water and TNT are approached by the using the Eulerian formulation with specified Equation of status (EOS). Us-Up’s form of Mie-Gruneisen equation is used for the water and JWL equation is used for TNT. The steel and soil are approached by shell and solid elements in Lagrangian scheme. Failure of steel is simulated by Johnson-Cook model with element deletion while the soil is approached by an existing geotechnical material model in Abaqus. The coupling between Eulerian and Lagrangian formulation is done by utilizing the surface contact features provided by Abaqus Explicit solver. A case study based on a real project is shown. The interactions are discussed in detail based on the numerical simulation results. Promising results have been obtained.

Presenting Author: Zhenhui Liu Western Norway University of Applied Science

Authors:

Zhenhui Liu Western Norway University of Applied Science
Ragnar Igland Aker Solutions AS