Current Features in SURMA
Our first release of SURMA for the Finnish Navy is purely intended for the design of naval vessels, taking into account explosions in air, inside or outside the vessel.
Civil version of SURMA, where the warhead analysis is stripped will be available on open markets in the future. This will be the ultimate way to provide information required to fulfil the IMO Safe Return to Port regulations.
All the functionality of SURMA is implemented in a single GUI based on NAPA manager concept.
Susceptibility
As regarding our other current development activities, we are searching for the ways of including signature related aspects in SURMA to offer the complete survivability assessment. Currently radar signatures can be assessed with CAST. There is a geometry and material link from SURMA to CAST.
Vulnerability
Damage calculation with rapid dynamic structural analysis and extended primary damage assessment (damage stability, longitudinal strength) with existing NAPA tools.
AIREX
SURMA calculates the pressure and fragment related damage resulting from a conventional warhead detonation in air, inside or outside the observed vessel. SURMA has its own pre-processing facilities for automatically creating the needed model for structural damage calculation and for adding e.g. ballistic protection.
Once the damage to the structures is calculated, the tools provided by NAPA are utilized for further analysis, thus assessing the damage stability and the longitudinal strength taking into account the flooded loading condition as well as the structural strength reduction.
Systems and Structure
If the vessel is still floating in one piece, the functionality of the shipboard systems is assessed by analyzing the damage to the system components in the damaged compartments.
NAPA also offers a possibility to create and export an FE mesh for FE analysis software if a more detailed structural analysis is desired, and we are implementing this tool tailored to meet our specific needs into SURMA very soon.
Fragments
The data required for this analysis is provided by the design ship model which contains compartments, structures and equipment. Some non-common tables are needed for weapon definitions, including the properties of explosives and also fragment properties if some kind of standard fragments (e.g. NATO 5.3 gr) are to be used.
Recoverability
System functionality analysis and secondary damage assessment, fore example flooding simulation with NAPA and fire and smoke spread analysis supported by the link to FDS. The latest feature under development is a link to IRM recoverability analysis software.
Future Development
UNDEX
We are currently implementing a method which uses a global stick model to assess the shock effects to whole ship model.
Fire
Also fire simulations are going to be included in SURMA in the near future. Our scheme for fire simulation is based on FDS (Fire Dynamics Simulator), a software developed by NIST (National Institute of Standards and Technology, U.S.) that also includes evacuation simulator EVAC developed by VTT (Technical Research Centre of Finland). We already have a proof-of-concept-stage implementation of this kind of simulation in SURMA.
Signatures
Analysis of electromagnetic and acoustic signatures under water are to be implemented next.