“We have a long history of regular investments in our products for the benefit of our customers. We see the importance of market-driven product development andfully intend to continue this strategy to best meet your business needs,” says Ole Jan Nekstad, Sesam Product Manager. “Supporting this objective, we are pleased to present a summary of the some of the updates in the January 2006 release of Sesam.”

Brix® Explorer hosting Sesam Brix Explorer for Sesam replaces the well-known Sesam Manager for all maintained Sesam users. It contains many improvements over Sesam Manager, including a graphical user interface that improves usability and efficiency and documents quality. It is now very easy to illustrate the work processes and the information flow graphically, which will increase productivity significantly. Brix Explorer for Sesam comes with a practical user guide and four pre-defined workflows. An initial template can be modified according to the needs of the project, and the application also allows the user to save a typical analysis project as a template to be used again in future projects. Templates can also be shared throughout the organisation, enabling company-specific guidelines to be built into work processes and ensuring that they are always used. Users familiar with Sesam Manager will see that Brix Explorer for Sesam incorporates the same features, allowing data to be specified quickly and easily for running various Sesam programs. Gap and contact analysis We have built a special module using Sestra to run non-linear contact formulations between specified points. To run a gap analysis, you need to specify which points to include (for example contact or noncontact) in Presel and specify gap computations in Brix Explorer for Sesam. This feature is particularly important in for example transportation analysis (contact between sea fastenings and jacket/deck/module) or jack-up analysis (contact between deck and leg in the jacks). Sestra also comes with improved features for eigenvalue analysis, better check of finite elements prior to analysis, and reduced sizes of temporary files (zero loads are not stored).

A HydroD project for a transport analysis. The barge, including the internal tanks, and jacket are created in Genie (right).

HydroD
As described in DNV Software News 2/2005, HydroD now includes hydrostatic and stability analysis. DNV Software will continue to add features to HydroD to provide a complete system for performing hydrodynamic analysis of ships and offshore vessels, with emphasis on closing the design loop.

The new features for panel and compartment modelling available in HydroD and GeniE make running a hydrodynamic analysis more intuitive and quicker than before. Typical changes to the analysis model can now be made within HydroD as opposed to using other Sesam programs such as Presel, Patran-Pre or GeniE as was done previously.

Design involves changes to the analysis parameters and model. The following new features have been added to HydroD to address these challenges:

Automatic computation of static equilibrium
For a given mass distribution and tank filling, the static equilibrium position (sinkage, trim and heel) is calculated by
HydroD. Alternatively the tanks can be filled to obtain a specified equilibrium position (sinkage, trim and heel).

Tank fillings specified in HydroD
Tank fillings can now be specified directly in HydroD. This is a great benefit for two reasons:

• The mass model is updated based on the given tank filling with an additional superelement. HydroD creates a new superelement with the tank masses represented by a cloud of point masses which is part of the mass model. Alternatively, if a user-defined mass matrix is given, a new mass matrix is calculated taking into account the mass of the internal tank fluid.
• HydroD will automatically adjust the elements to receive pressure in internal tanks of the structural model used by Wadam when doing load transfer to take into account the filling height. This will save the user from having to manually update the structural model (setting dummy hydro pressure according to filling height) and create different structural models for each load case.

No need to re-model the panel model if the trim or heel angle is non-zero
HydroD will adjust the panel model, taking account of the trim and heel angle for input to Wadam. In addition, if a half or quarter panel model is used, HydroD will help the user set up unique superelements to be able to take into account the trim and heel angle.

This means the process of setting up the analysis for different load cases is much simpler, and there is no longer need to manually adjust the panel model in Presel or the panel modelling tool (Patran-Pre or GeniE) to take into account the trim and heel angle. One panel model is used for all load cases.

Author: Erik Ian von Hall and Torgeir Vada