CE595FiniteElementsinElasticity-PurdueUniversity.pptVIP

Plate Bending in ABAQUS “Thick” versus “thin” conventional shell elements ABAQUS includes general-purpose, conventional shell elements As well as conventional shell elements that are valid for thick and thin shell problems. The general-purpose, conventional shell elements provide robust solutions for most applications In certain cases, for specific applications, enhanced performance may be obtained with the thin or thick conventional shell elements. For example, if only small strains occur and five degrees of freedom per node are desired. Plate Bending in ABAQUS General-purpose conventional shell elements These elements allow transverse shear deformation. They use thick shell theory as the shell thickness increases and become discrete Kirchhoff thin shell elements as the thickness decreases The transverse shear deformation becomes very small as the shell thickness decreases. Element types S3/S3R, S3RS, S4, S4R, S4RS, S4RSW, SAX1, SAX2, SAX2T, SC6R, and SC8R are general-purpose shells. Plate Bending in ABAQUS Thick conventional shell elements Thick shells are needed where transverse shear flexibility is important and second-order interpolation is desired. This occurs when the thickness is more than about 1/15 of a characteristic length on the surface of the shell, such as the distance between supports for a static case ABAQUS/Standard provides element types S8R and S8RT for use only in thick shell problems. Plate Bending in ABAQUS Thin conventional shell elements Thin shells are needed in cases where transverse shear flexibility is negligible and the Kirchhoff constraint must be satisfied accurately (i.e., the shell normal remains orthogonal to the reference surface). For homogeneous shells this occurs when the thickness is less than about 1/15 of a characteristic length on the shell surface. ABAQUS has two types of thin shell elements: those that solve thin shell theory (the Kirchhoff constraint is satisfied analytically) and those that converge to thin shel