Flexcom Tutorial: General Software Overview

Welcome to Flexcom 8, the pre-eminent industry-leading software for the design and analysis of risers and subsea structures for the world’s most demanding offshore projects. This short presentation is divided up into 4 parts, Introduction, Model Building, Finite Element Analysis and Postprocessing. In the first example, the flexible riser system is subjected to regular wave loading in a time domain dynamic simulation. The mid-water arch is modelled as a rigid frame structure, which supports an arrangement of contact surfaces, with uplift provided by buoyancy tanks. The mesh density in the contact region is relatively fine in order to accurately capture the interaction between the risers and the arch structure. The plan view shows the arch moving laterally in response to the applied wave loading. Flexcom can graphically display element forces, such as effective tension or bending moment, and this provides the engineer with an intuitive visual representation of the finite element results. Here we are focusing on the tethers, and using the colour contouring feature to visualise effective tension variations. As well as facilitating rotating, panning and zooming, the Model View provides other useful features such as displaying node and element numbers, coordinate data, seabed topography, water surface profile, and many more. Flexcom uses an industry-proven finite element formulation, incorporating a hybrid beam-column element with fully coupled axial, bending and torque forces. Flexcom’s innovative solution technique is ideally suited to the modelling of slender offshore structures, which are characterised by significant geometric nonlinearities. To complement the time domain analysis, Flexcom also offers a highly efficient frequency domain solution. Typically used for screening analysis, it results in huge savings in terms of run time. Analysis jobs may be initiated very easily, for example via the Branch run feature. This automatically runs the selected file and all dependent files in the correct sequence. The software is also designed to simplify the quality assurance process. Designated icons provide an indication of the status of each analysis, informing the user of successfully completed runs and highlighting any that require further attention. If any alterations are made to the input data, a status icon alerts the user that the results could be obsolete and potentially misleading. These features reduce administrative overhead, allowing engineers to focus on more technical aspects and design challenges. Metocean data which underpins structural fatigue assessment is typically presented as a scatter diagram. Unlike regular wave periods and directions which tend to be round numbers, the Hs and Tz values are typically numerical with several decimal places. Such data may also be readily imported from a spreadsheet into Flexcom. Again a single, parameterised master template file is capable of generating all the required input files. Note also how a suitable file name may be automatically created to reflect the particular combination of Hs and Tz contained within that file. Existing users of Flexcom may be interested to know that Flexcom 8 runs up to 40% faster than Flexcom 7. Flexcom provides a range of post-processing options. Database post-processing is quite popular, where results are presented graphically. You may select from a list of variables including effective tension, bending moment, and so on. If you are viewing a time history plot and a structural animation on screen simultaneously, a moving vertical line on the plot provides a direct link between the structural response and the associated engineering parameter. Flexcom is accompanied by a dedicated Excel Add-In which allows you to extract results from Flexcom database files directly into Excel. For ease of use, some standard templates are provided on the Flexcom ribbon control. These are designed to instantly deliver standard solutions, but may be easily customised subsequently to meet particular requirements of individual users. Whereas database post-processing is very graphical and largely plot based, summary post-processing by contrast is mainly text based. A summary output file typically contains a succinct output of maximum, minimum, range and standard deviation of parameters of interest. Following the summary postprocessing of several individual analyses in a load case matrix, a collation facility subsequently assembles all the output data into a central spreadsheet. This delivers tangible benefits for engineering teams, making it faster and easier to compile output data and extract pertinent results If you would like further information on Flexcom, please send an email to [email protected], or visit our website (www.mcskenny.com).