... offshore tech dynamic equation simulation frequency procedure sea state tension response fatigue damage htfd approach spectrum mooring system assumption Plouedmgs of the FII st (1990 J EU/ opean OffshOi e Mecham(s Symposium TlOndhelm, NOIway, 20-22 August 1990 Copyl/ght © 1990...

...-tensioned anchored lines for guiding a GBS as shown in Figure 1. The main phases of this procedure are as follows: approach phase coupling and tensioning of wires close positioning phase touch-down and positioning verification 1\ ~ I-' I !+ I .. Figure 1: Con deep 2/17 platform For the selected example...

... distribution is empirically formulated on the base of a number of stress range probability histograms obtained from the rainflow cycle counting algorithm using the Monte-Carlo procedure. Although the probability distribution introduced is general for both linear and nonlinear damage accumulations, in the paper...

... to be accomplished in a rational manner The procedures suggested should allow the question of the acceptability of current stress limits to be explored further INTRODUCTION The design of submarine plpehnes is based on a vanety of codes and regulations, which are, in many cases, open to conflicting interpretation...

... prediction procedure it is possible to evaluate - for ,instance - the influence exerted upon the oscillating bodies by the geometry of the considered motion patterns (also the most complex ones), by the oscillation past history, by Keulegan Carpenter (KC) number, by the interaction of different currents...

... ABSTRACT A scaling procedure for mooring experiments with lines containing buoys attached to them is outlined. It is shown that dynamic similitude is ensured only if the elasticity of each segment of the line is properly modelled through the introduction of elastic springs. The validity...

... inclination. A detailed discussion of these effects is found in /4/. Methods for analysis Various methods for dynamic analysis exist. In the follOWIng the most important methods will be commented in relation to the prevIOusly described non-linearities. * Frequency domain (FD) analysis An FD procedure based...

... of the anchor damage to failure statistics and stressing its importance for an assessment of safety of pipelines. ship mechanics anchor stiffness operation fluke frequency anchor damage offshore pipeline scenario north sea protection cover deflection interaction deformation procedure...

... It Without knowledge of Umetanu and Hirai Both procedures consist of an elastiC FEM-run whereby the surface of the deSign proposal IS shifted In direction of the normal of the initial surface according to a given diS- tribution of stress components or elastiC energy denSities In both papers growth...

... conditions, resonance accom- 358 panied by large amplitude vibrations of the pipeline may occur. In this situation the welds may be exposed to fatigue damage. Analysis procedures for free span assessment have reached a good quality level, in particular as regards structural modelling. The boundary conditions...

... to numerical modelling procedures and to assumptions made about the damping. When there was no current, the damping was affected by first-order velocities, and the damping coefficient by boundary layer forces and by the partial development of flow separation and vortex shedding at low Keulegan-Carpenter...

...~ng. D~fferent uncerta~nty sources re- levant for these failure conditions are discussed and ~ncluded ~n the analys~s. Two alternat~ve approaches for safety assessment are indicated. The rel~abil~ty calculat~on procedure can be applied d~rectly repre- senting a full probab~list~c des~gn or ~ndirectly...

... assumption denote noise approximation stochastic linearization mssl standard method stochastic linearization method extreme response response level artificial intelligence deviation measure prediction procedure accurate estimate offshore structure exceedance probability equation...