@article{GENERAL,
      author = {Craven, R and Tanner, D and Graham, D},
      url = {http://library.imarest.org/record/10640},
      journal = {Conference Proceedings of INEC},
      title = {Modernising submarine structural design capabilities for  next generation submarine},
      abstract = {Do semi-empirical equations written in FORTRAN have a  place in submarine design in the age of digital twins,  genetic algorithms and coupled multi-physics  simulations?
Submarine programmes do not have the  opportunity to build a prototype, due to the cost and time  required to design and build a submarine the first boat  manufactured is the first of class. As a consequence,  submarine designs tend to be conservative and incremental  in their development. The basic analytical design equations  for UK submarine pressure hulls were developed in the  1960s, and coded into FORTRAN in the 1970s. These equations  have been proven by model scale testing and physical trials  and by continued operation of the current and previous  classes of UK submarine.
Over the last six years QinetiQ  have worked closely with the UK Ministry of Defence (MOD)  to migrate these semi-empirical equations written in  FORTRAN from obsolete HPUX based hardware to modern PC  based systems with new graphical and command line user  interfaces. These tools have been verified against the  legacy code, updated to reflect the current UK structural  design standards and fully documented. These updates have  provided a modern, intuitive and supported user interface  to the legacy equations, enabling their continued use. The  new interfaces have also enabled the equations written in  FORTRAN to be linked to modern tools such as Isight for  process automation and optimisation. This enables a design  of experiment (DoE) or optimisation studies with ten  thousand iterations to be run within a week using a known,  trusted and well understood toolset.
The migration and  updates to these legacy tools have enabled them to be used  in a way that would never have been considered when they  were developed. The new approach enables a much wider  exploration of the design space, and the ability to  understand the sensitivity of the design to a given  parameter. The capability has supported the development of  a suite of automated Finite Element tools in Abaqus CAE  Finite Element (FE) software, which automate and  standardise the building and analysis of submarine pressure  hull compartments. The ability to quickly and easily verify  the FE analysis against the analytical tools for known  cases has accelerated the development and confidence in the  standardised FE process and by expanding the range of  designs compared has started to identify the limitations of  the analytical tools.
Coupling the analytical and FE tools  together using Isight enables a potentially powerful  parametric design tool, which can quickly run large numbers  of low fidelity analytical solutions to identify potential  solutions for further evaluation using linear and  non-linear FE analysis which could form the basis for a  digital twin of the submarine structure for use to support  the platform through life.},
      number = {GENERAL},
      doi = {https://doi.org/10.24868/10640},
      recid = {10640},
      address = {2022-08-17},
}