Hybrid composite tensile armour wires in flexible risers: A multi-scale model

Effect of Miniature Cracks on the Fracture Strength and Strain of Tensile Armour Wires

Tensile armour wires provide a resistance to longitudinal stresses. Flexible pipe manufacturers need to know the effect of defects such as scratches and cracks, with dimensions less than 0.2mm which is the limit of the current nondestructive detection technology, on the fracture stress and fracture strain of the wire for quality assurance purposes. Recent research involving the determination of...

A multi-scale code for flexible hybrid simulations

Multi-scale computer simulations combine the computationally efficient classical algorithms with more expensive but also more accurate ab-initio quantum mechanical algorithms. This work describes one implementation of multi-scale computations using the Atomistic Simulation Environment (ASE). This implementation can mix classical codes like LAMMPS and the Density Functional Theory-based GPAW. An...

Design of Composite Risers for Minimum Weight

The use of composite materials in offshore engineering for deep sea oil production riser systems has drawn considerable interest due to the potential weight savings and improvement in durability. The design of composite risers consists of two stages: (1) local design based on critical local load cases, and (2) global analysis of the full length composite riser under global loads and assessment ...

Multi-Scale Approach to Investigate the Tensile and Fracture Behavior of Nano Composite Materials

Boundary Control of flexible marine risers ⋆

Abstract: A method to design a boundary controller for global stabilization of threedimensional nonlinear dynamics of flexible marine risers is presented. Equations of motion of the risers are first developed in a vector form. The boundary controller at the top end of the risers is then designed based on Lyapunov’s direct method. It is shown that when there are no environmental disturbances, th...