In this paper, the Combined Eulerian-Lagrangian (CEL) capabilities of Abaqus are used to determine both vertical and lateral soil resistance to leg motions of a representative jack-up while going on location. There are two significant effects that have not been addressed by these methodologies: the fact the seabed profile changes after each leg impact, and the energy dissipation properties of the soil. The majority of analyses represent the seabed as a nonlinear spring, attempting to match the penetration curves which account for spud can shape and soil properties. State-of-the-art analysis methods to establish adequate limits for going on location include nonlinear time-domain response analysis of the units, accounting for jacking speed and spud can shape as well as wave directionality, water depth and soil conditions.
#How to calculate damage orcaflex iso
Unlike the well-established guidelines from Class or ISO for units in the elevated condition, the guidelines for going on location analyses have yet to be fully developed, let alone become standard. There have been a number recent improvements for the analysis of self-elevating units during the transition phase commonly referred to as the "going on location" or "emplacement" phase (i.e., the transition from the afloat condition to the pinning of the legs). (2004) performed CFD simulations of forced oscillations and forced heave / pitch motions of the CALM buoy model to provide more accurate evaluation of the hydrodynamic damping coefficients. Most of the numerical models use empirical coefficients for lift, drag and added mass in their simulation of the CALM buoy systems, such as those presented by Ryu et al. Several numerical investigations have been performed for dynamic analysis of the CALM buoy system. Therefore, it is essential to develop advanced numerical methods for accurate estimate of dynamic motion for CALM buoys. These features for buoy can result in dangerous motions causing fatigue damage in mooring and flowlines systems. Compared to other floating structures like Floating Production Storage and Offloading (FPSOs) or Tensioned Leg Platform (TLP), CALM buoy is more sensitive to the response of mooring lines and oil offloading lines due to its considerably smaller inertia, damping and hydrostatic stiffness. INTRODUCTION The CALM system is widely used as an efficient and economic single point mooring system in offshore engineering applications. With the study it can be verified that the coupled method is able to provide an accurate simulation of the hydrodynamic behavior of the CALM buoy system.
#How to calculate damage orcaflex code
The coupled code was then employed for the simulation of two degree-of-freedom vortex-induced motion of a CALM buoy in uniform currents to illustrate the capability of the present CFD approach for coupling mooring analysis of offshore structures. The coupled code was calibrated first for free-decay case and compared with model test data. An interface module is established to facilitate interactive coupling between the buoy and mooring lines. The mooring system is simulated with a nonlinear finite element code, MOORING3D. In the FANS code, the fluid domain is decomposed into multi-block overset grids and the Large Eddy Simulation (LES) is used to provide accurate prediction of vortexinduced motion of the buoy. offshore projects planning and execution (2)ĪBSTRACT In the present study, the Finite-Analytic Navier-Stokes (FANS) code is coupled with an in-house finite-element code for time-domain simulation of the hydrodynamic response of Catenary Anchor Leg Mooring (CALM) buoy system.
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