Introduction

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 Pre&Postprocessor

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.

GMSH: Mesh Generations of X-SEA AutoCAD

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
OpenFAST Multiple calculation of wind turbine loads of OpenFAST with graphical input
X-SEA Coupled with OpenFAST Structural analysis and design of offshore structure coupled with OpenFAST wind turbine load
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

Introduction of X-SEA (Solver)

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

X-SEA uses 64 bit Intel Parallel Direct Sparse Solver (PARDISO).

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