Here you will find the latest news on the development of OrcaFlex. Alongside our LinkedIn page, it is a valuable source of information about what we are up to!
A new diffraction example is now available on our website: L05 Panel pressures.
The example is a post processing exercise. Using the models built during example L04, we demonstrate how panel pressures are reported using the OrcaFlex interface to Python. We discuss panel pressure results reported directly from an OrcaWave results file. We also explore how features released in version 11.5 can be used to compute a time history of panel pressure.
Unlike the standard OrcaWave result set that describe wave induced loads per body, panel pressure results allow the user to disaggregate the wave induced load at finer resolution. Whilst OrcaFlex does not make use of these results, they may be used to inform structural analysis in another dedicated program.
We hope you find this new example useful!
3D scatter plot of panel pressure, plotted at the centroid of each mesh panel, reported at a simulation time of 5s.
A new diffraction example is now available on our website: L04 Sectional bodies. The example demonstrates how sectional bodies, introduced in v11.4, can be used to enhance the multibody analysis capabilities of OrcaWave & OrcaFlex.
Prior to v11.4, OrcaWave & OrcaFlex were capable of undertaking multibody analysis, provided that each body could be considered closed. This capability is useful when modelling two or more independent structures in close proximity. Furthermore multibody analysis can be used to analyse the loads within a single structure, provided that structure can be represented by a collection of distinct meshed bodies (see Example L03).
In v11.4 onwards, a new type of body has been introduced that we refer to as a sectional body. Users are able to construct structures from multiple sectional bodies. Each sectional body references an open ended mesh. When considered as a group, the sectional body meshes unite to represent the closed hull.
The example focusses on a semi-sub platform that closely resembles the VolturnUS platform, as modelled in example K03. The platform is represented using a system of seven sectional bodies. We show how sectional multibody analysis can be used to evaluate the distributed loads within a structure. Furthermore we demonstrate how this approach can be used in tandem with OrcaFlex line and constraint objects to model a degree of flexibility in the platform. We anticipate that the results reported by OrcaFlex could be used to inform a targeted analysis conducted with specialised structural analysis software.
We hope that this example is informative and helps to expand your knowledge of the diffraction capabilities within our software.
Semi-sub platform modelled as a sectional multibody system
A new example is now available on our website: L03 Semi-sub multibody analysis. This example focusses on a semi-sub platform that closely resembles the OC4 platform, as modelled in example L02.
In the L02 example, we assume the platform is a single rigid body. In the L03 example, we are interested in the loads acting through the connecting members. Consequently, we have divided the platform into four distinct floating bodies and used OrcaWave to run a multibody diffraction analysis. In OrcaFlex, the four vessel objects are connected via line objects with structural properties that represent the cross bracings and pontoons. Further details can be found in the accompanying PDF description document.
Please note that example L03 takes advantage of recent developments to improve the workflow when defining external stiffness for multibody analyses. Therefore, this example is intended for use with OrcaWave and OrcaFlex version 11.4 onward.
In version 11.4 we also developed OrcaWave and OrcaFlex to be capable of undertaking multibody analyses for objects consisting of multiple sectional bodies. This new feature is not considered as part of this example, although we hope to develop an example that will demonstrate this feature in the future.
We hope that you will find this latest example helpful and informative.
We have recently uploaded a new technical note to our website titled OrcaWave – working with meshes. The document focuses on the use of panel meshes in our diffraction analysis tool OrcaWave. We describe the link between mesh refinement and results quality. Furthermore we discuss how features such as symmetry conditions, calculation method and meshing technique can be used to report converged results whilst reducing run time and memory requirement.
This new resource can be found alongside a range of existing technical notes on the Papers and technical notes page of our website.
