Subsea pipeline walking with velocity dependent seabed friction

Halliburton sets new deepwater record with subsea pipeline testing device

Velocity dependent friction laws in contact mode atomic force microscopy.

Friction forces in the tip-sample contact govern the dynamics of contact mode atomic force microscopy. In ambient conditions typical contact radii between tip and sample are in the order of a few nanometers. In order to account for the large interaction area the dynamics of contact mode atomic force microscope (AFM) is investigated under the assumption of a multi-asperity contact interface betw...

Improved FTA Methodology and Application to Subsea Pipeline Reliability Design

An innovative logic tree, Failure Expansion Tree (FET), is proposed in this paper, which improves on traditional Fault Tree Analysis (FTA). It describes a different thinking approach for risk factor identification and reliability risk assessment. By providing a more comprehensive and objective methodology, the rather subjective nature of FTA node discovery is significantly reduced and the resul...

A Finite Element Model and Electronic Analogue of Pipeline Pressure Transients With Frequency-Dependent Friction

phase turbulence, but underpredict the two-phase fluctuation velocities, and the difference between the two model predictions is not obvious. 4. The nonlinear k-«-kp model has no problem of convergence encountered in the implicit algebraic stress model. 5. In two-dimensional flows with small geometrical sizes the NKP model can save about 50% computation time than the USM model. However, in thre...

Reinterpretation of velocity-dependent atomic friction: influence of the inherent instrumental noise in friction force microscopes.

We have applied both the master equation method and harmonic transition state theory to interpret the velocity-dependent friction behavior observed in atomic friction experiments. To understand the discrepancy between attempt frequencies measured in atomic force microscopy experiments and those estimated by theoretical models, both thermal noise and instrumental noise are introduced into the mo...