- The current version of X-SEA includes the results of extensive research and development base on finite element program XFINAS, which was originally developed in Imperial College, London.
- The X-SEA is an integrated finite element structural analysis software that provides for the nonlinear dynamic analysis and design of offshore steel and concrete structures, including oil and gas and wind farms.
- The X-SEA provides a high-performance graphics of AUTOCAD Add-in Interface with interactive and visual environment for the analysis and design of offshore structures.
- The power of X-SEA is further enhanced by its speed and 64-bit capability with
**Multi-core Parallel Direct Sparse Solver**using INTEL PARDISO. - For the design of offshore wind turbine structure, coupled dynamic analysis of the
**OpenFAST**(NREL, USA) and X-SEA can be combined with X-SEA environmental load. - Post-processing of integrated analysis results for Fatigue Limit State analysis (FLS) and Ultimate Limit State (ULS) analysis (GH Bladed & OpenFAST).

**Analysis option**

**AutoCAD (Autodesk, Inc. USA)**becomes most popular and user-friendly CAD software which is used by the world-wide engineer.**AutoCAD**does not only have powerful, perfect graph drawing and editing ability but also allows users to carry out a Finite Element Analysis.- Pre/postprocessor of X-SEA has integrated with AutoCAD 3D using "ADD IN" function of AutoCAD.
- X-SEA user can draw and modify the 3 dimensional (3D) model of the offshore structure on the screen of AutoCAD 3D. By using same AutoCAD 3D model, X-SEA analysis does not need export/ import model which is generally used in commercial FEM software.
- Through interactive approach of AutoCAD, the finite element analysis makes user obtain calculation results and report with visualization of postprocessing in AutoCAD environment.
- The AutoCAD X-SEA contains a template that allows the user to easily create the model of monopile, tri/tetrapod, and jacket structures with line elements.
- The window of the template contains options to generate meshes of line elements and render 3D shapes. This option enables users to model geometries easily and rapidly as compared with CAD drawings.

X-SEA has a license from GMSH(https://gmsh.info/). GMSH is an 3D finite element mesh generator with a built-in X-SEA AutoCAD engine and provides a fast, light and user-friendly meshing tool with advanced visualization capabilities.

**Pop-up Window** of GMSH

**Open Mesh** in AutoCAD Screen

Mesh Generation of offshore jacket K

joint using 4-node shell element

Mesh Generation of offshore concrete gravity

structure using 3D 4-node tetrahedral element

Option | Features |

X-SEA AutoCAD | Analysis and design of offshore wind turbine structure |
---|---|

X-OpenFAST AutoCAD | Analysis and design of offshore wind turbine structure Pre&Postprocessor of OpenFAST 3.0 |

Solution Item |

Inplace Analysis |

Nonlinear analysis of frame, shell & solid elements(Geometrical and Material nonlinearity) |

Eigenvalue Analysis (Frequency and Critical buckling load) |

Linear Dynamics Analysis (Time Integration & Mode Superpostion, Frequency Domain) |

Nonlinear Dynamics Analysis (Dynamics of large deformation of elastoplastic analysis using frame, shell and solid elements) |

Environmental Load |

Regular (5 Kinds) and Irregular wave (PM, JONSWAP Spectrum) |

3D Morison wave pressure |

3D Linear Diffraction wave Theory (Shell & Solid element) |

Prestressed concrete analysis |

SCF factor |

Fatigue Analysis in Frequency and Time Domain |

Mooring Analysis of Floating Structure |

Pile Foundation Analysis (p-y,t-z,Q-z) and Pile Super element |

Steel Code Check & Design |

Ship Collison to Steel and Concrete offshore structure |

Drafting & Material take off |

Coupled Dynamic Analysis of OpenFAST turbine and substructures |

Postprocessing the Fatigue analysis using GH-Bladed and FAST 8 output |

Lifting/Transportation/Fabrication analysis |

How to solve : **[K]{x}={f}, {x}**= ?**[K]=**

- The newly restructured X-SEA using 64 bit PARDISO package is very fast, high performance, robust and memory efficient software for solving large sparse symmetric and unsymmetric linear systems of equations on shared memory multiprocessors.
- The 64 bit system of X-SEA is extremely faster than 32bit X-SEA shown in the table.
- The degree of freedom of model is almost unlimited by the efficient memory management system.

Test of square plate under uniform pressure using 4-node shell element (256X256 meshes).

Meshes | Elements | CPU Time (sec) in 64bit | Result (m) Analtical Sol:1.264 | Non-dimension |

2 x 2 | 4 | 0.19 | 1.211 | 0.95807 |
---|---|---|---|---|

4 x 4 | 16 | 0.22 | 1.251 | 0.98972 |

16 x 16 | 256 | 1.05 | 1.262 | 0.99842 |

32 x 32 | 1,024 | 2.94 | 1.265 | 1.00079 |

48 x 48 | 2,304 | 5.2 | 1.265 | 1.00079 |

64 x 64 | 4,096 | 7.95 | 1.265 | 1.00079 |

96 x 96 | 9,216 | 16.97 (133.63 Sec in 32 bit) |
1.265 | 1.00079 |

128 x 128 | 16,384 | 29.17 | 1.265 | 1.00079 |

196 x 196 | 38,416 | 74.11 | 1.265 | 1.00079 |

256 x 256 | 65,536 | 131.52 | 1.265 | 1.00079 |

Analytical solution: 1.264