X-SEA

Element library

X-SEA Element Library

X-SEA Linear & Nonlinear Element library X-SEA Nonlinear Material
Frame element XFRAME : 2-node frame element with warping
(7 dof, Shear deformation, tapered)
Elastoplastic : Von Mises, CONCRETE CREEP
Shell element XSHELL3-QSI : 3 node quasi-conforming
XSHELL4-ANS : 4 node Assume Natural Strain
Elastoplastic : Von Mises with strain hardeing, Ivanov-Yulishin, Concrete Elsto-plastic & Elasto-plastic Fracture, laminate composite, Concrete creep
Solid element XSOLID4T & XSOLID10T : 4 & 10 node, Tetrahedral XSOLID8-EAS: Enhanced Assumed Strain 8 node Elasto-plastic : Von-Mises, Mohr-Coulomb, Drucker-Prager, Tresca
Truss element

XCABLE–Parbolic
XCABLE–Catenary
XCABLE-Mooring

Elastoplastic : Von Mises
Cable element XTRUSS : 2-node three dimensional element 5-point nonlinear model
Spring element XSPRING : 3-D Spring
Link Element Gap, Hook, Gap-Hook
Interface element 1-D, 2-D,3-D (Bond-slip element)
Tendon element 3-D prestressing tendon

X-SEA Frame Element: 7 D.O.F

Structural Member’s offset

When two or more members are connected with the same joint, there is some overlap of the cross section.
To solve, “member offset” function was applied. Offset member will be divided into 2 parts. Flexible zone and offset rigid zone.
Offset rigid zone will be calculated as rigid and never affect axial and torsional deformation. The rest element is assumed to be frame element deformations.

Truss Element stiffness matrix is calculated in the local coordinate system and transformed into the global coordinate system automatically.

A truss element is structural member capable of transmitting stress only in the direction normal to the cross section.
The normal stress is assumed to be constant over the cross-section area.
The two-dimensionaland thress dimensional truss elements are shown in the X-SEA element library.
The linear and geometrically nonlinear element modules are available.

A three dimensional 2-node frame element can be used for the linear and nonlinear dynamic analysis of 3-D offshore framed structures

The XFRAME element has a spring and offset for easy and efficient modeling
Fiber cross section analysis using 8-node element
Geometrical and Material nonlinear frame element
Tapered frame element
Warping analysis of steel cross section of frame element.

Lare displacement elastic and elasto-plastic Analyses of Lee's frame to validate the nonlinear performance

X-SEA Shell Element: 6 D.O.F

The formulation of the shell elements use Mindlin-Reissner theory
Assumed Strain Method and Quasi-Conforming method to remove the shear locking
Co-rotational formulation in nonlinear analysis
The thin shell structures.
Rotation free X-Shell 3 node element is very efficient in memory and CPU time.

Verification of large displacement elstoplastic analysis of shell structures

Application of offshore wind turbine

  • Transition Pieces of Jacket structures is discretized with many shell elements

  • Connection Joint of Jacket structures is discretized with many shell elements

X-SEA Cable Element

X-Catenary Cable Element

The nonlinear cable element has 2 nodes and total 6 DOF. Its can resist only tensile load i.e. it has no strength and stiffness in the compressive direction.

The stiffness of the catenary cavle element is dependent on its weight, length and the tension force itself. The nonlinear force-displacement relationship was included to take into account the sag effect that is importance in the practical cable structures.

The multi-linear material behavior was also incuded into the element formulation, thus the element can be used in geometric and material nonlinear analysis of the cable structures such as suspension bridges.

T is the line tension, A is the cross-section area of the line, E represents the elasticity modulus, F and D correspond to the drag or mean hydrodynamic forces both normal and tangential direction, respectively,

The Xcable-Mooring is provided fot helping users to generate true profile of the mooring line whith seabed contract. This line will give begin and end position of seabed contract.

X-SEA 3D Solid Element: 3 D.O.F

Three types of solid dlements are available.
XSolid-4T - 4 node tetrahedron,
XSolid-10T - 10 node tetrahedron,
XSolid-8-EAS - 8 node hexahedron with enhanced assumed strains.
XSolid-shell-8- - 8 node assumed strain and enhanced assumed strains.

Advantages
The solid-shell element is analytically integrated through the thickness.
Computationally efficient element for large concrete structures (more than 50% CPU time saving)
Section force, moment & stress at node
The same DOF as shell element but easier and smoother than shell element model in the tapered beam structures
The calculation of the memberane force, moments and stresses at node by stress smoothing

X-SEA Interface Element: Bond-slip behavior

For the Bond-slip behavior of Grouted Connection, the Interface Element is used for the interface between transition piece and monopile Wind Turbine Offshore Structure.