PIPE-LAY MODELS CAN PREVENT MISTAKES

For modeling the configuration of the stinger, lay pipe, or both, and for simulating condistions such as current and wave forces to achieve the most efficient and economical laying procedure, Engineering Technology Analysts Inc. has developed ETA/PIPLAY, which is a nonlinear, three-dimensional, specialized type of large-deflection, finite-element, structural-analysis computer program. It simulates the axial, shear, and bending stresses and deflected shape of pipe as it leaves a pipe-laying barge and descends to the ocean bottom. ETA/PIPLAY functions equally well for a near-catenary situation (e.g., 12 in. OD pipe in 1500 ft of water) as for more rigid configurations (e.g., 48 in. OD pipe in 150 ft of water). The program can handle problem conditions such as varying pipe size; effects of concentrated loads such as valves or buoy supports, cable pickups from bottom; wave and current loadings; varying support conditions at top or at mud line; and effects of barge motion. A case study of the use ETA/PIPLAY under conditions typical of the North Sea is presented.