تفاوت المان شِل، لاینر و بیم در فلک سه بعدی Shell Structural Elements… — پشتیبانی نرم افزارهای ژئوتکنیکی (وبسایت geosoft.ir) — TG.ME

‌ تفاوت المان شِل، لاینر و بیم در فلک سه بعدی Shell Structural Elements — Shell structural elements are three-noded, flat finite elements. Five finite-element types (2 membrane elements, 1 plate-bending element and 2 shell elements) are available. A physical shell (i.e., an arbitrarily curved, shell structure of either isotropic or orthotropic material) can be modeled as a faceted surface composed of a collection of shell elements. The structural response of the shell is controlled by the finite-element type (to resist membrane loading only, bending loading only, or both membrane and bending loading). Each shell element behaves as an isotropic or orthotropic, linearly elastic material with no failure limit; however, one can introduce a plastic-hinge line (across which a discontinuity in rotation may develop) along the edges between elements, using the same double-node procedure as is applied to beams. Shell elements may be rigidly connected to the grid such that stresses develop within the shell as the grid deforms, and they may be loaded by point loads or surface pressures. Shell elements are used to model the structural support provided by any thin-shell structure in which the displacements caused by transverse-shearing deformations can be neglected. Liner Structural Elements — Liner structural elements are three-noded, flat finite elements that can be assigned any of the five finite-element types available for shell elements. A physical liner can be modeled as a collection of liner elements that are attached to the surface of the FLAC3D grid. In addition to providing the structural behavior of a shell, a shear-directed (in the tangent plane to the liner surface) frictional interaction occurs between the liner and the FLAC3D grid. Also, in the normal direction, both compressive and tensile forces can be carried, and the liner may break free from (and subsequently come back into contact with) the grid. Liner elements are used to model thin liners for which both normal-directed compressive/tensile interaction and shear-directed frictional interaction with the host medium occurs, such as shotcrete-lined tunnels or retaining walls. Beam Structural Elements — Beam structural elements are two-noded, straight, finite elements with six degrees of freedom per node: three translational components, and three rotational components. A physical beam (i.e., an arbitrarily curved, beam structure of isotropic material and bisymmetrical cross-section) can be modeled as a collection of beam elements. Each element behaves as a linearly elastic material with no failure limit; however, it is possible to introduce a limiting plastic moment, or even a plastic hinge (across which discontinuity in rotation may develop), between elements. Beam elements may be rigidly connected to the grid such that forces and bending moments develop within the beam as the grid deforms, and they may be loaded by point or distributed loads. Beam elements are used to model structural-support members in which bending resistance and limited bending moments occur, including support struts in an open-cut excavation and general framed structures loaded by point or distributed loads. #فلک @flac_abaqus @flac2d www.geosoft.ir