A section contains information about the properties of a part or a region of a part. The information required in the definition of a section depends on the type of region in question. For example, if the region is a deformable wire, shell, or two-dimensional solid, you must assign a section to that region that provides information about the region's cross-sectional geometry. Likewise, a rigid region requires a section that describes its mass properties. Most sections must refer to a material name. Beam sections must also refer to a profile name.
When you assign a section to a part, ABAQUS/CAE automatically assigns that section to each instance of the part. As a result, the elements that are created when you mesh those part instances will have the properties specified in that section.
Sections are named and created independently of any particular region, part, or assembly. You can assign a single section to as many different regions as necessary. You can use the Property module to create solid sections, shell sections, beam sections, and other sections.
Solid sections
Solid sections define the section properties of two-dimensional, three-dimensional, and axisymmetric solid regions.
Homogeneous solid sections. Homogeneous solid sections consist of a material name. In addition, if the section will be used with a two-dimensional region, you must also specify the section thickness. (You have the option of specifying a plane stress or plane strain thickness even if the section will be assigned to a three-dimensional region. ABAQUS/CAE ignores the thickness information if it is not needed for the region type.)
For more information, see “Creating homogeneous solid sections,” Section 12.11.1.
Generalized plane strain sections. Generalized plane strain sections consist of a material name, thickness, and wedge angles about the global 1- and 2-axes. You can assign generalized plane strain sections only to two-dimensional planar regions.
For more information, see “Creating generalized plane strain sections,” Section 12.11.2.
Shell sections
Shell sections define the section properties of shell regions. Shells model structures in which one dimension (the thickness) is significantly smaller than the other two dimensions and in which the stresses in the thickness direction are negligible. You can define one or more layers of reinforcement (rebar) in shell sections. For more information, see “Understanding rebar in shell sections,” Section 12.2.4.
Homogeneous shell sections. Homogeneous shell sections consist of a shell thickness, material name, section Poisson's ratio, and optional rebar layers. You can choose to provide the section property data before the analysis or to have ABAQUS calculate (integrate) the cross-sectional behavior from section integration points during the analysis. If the latter is chosen, options are provided to control the section integration and temperature variation through the thickness.
For more information, see “Creating homogeneous shell sections,” Section 12.11.3.
Composite shell sections. Composite shell sections consist of layers of materials, a section Poisson's ratio, and optional rebar layers. For each layer of material, you must specify a material name, thickness, and orientation. You can choose to provide the section property data before the analysis or to have ABAQUS calculate (integrate) the cross-sectional behavior from section integration points during the analysis. If the latter is chosen, options are provided to control the section integration and temperature variation through the thickness.
For more information, see “Creating composite shell sections,” Section 12.11.4.
Membrane sections. Membranes represent thin surfaces in space that offer strength in the plane of the surface but have no bending stiffness. Membrane sections consist of a material name, membrane thickness, section Poisson's ratio, and optional rebar layers.
For more information, see “Creating membrane sections,” Section 12.11.5.
Surface sections. Surface sections represent surfaces in space that have no inherent stiffness and behave like membrane elements with zero thickness. Surface sections consist of optional rebar layers.
For more information, see “Creating surface sections,” Section 12.11.6.
Beam sections
Beams are used in two and three dimensions to model slender, rod-like structures that provide axial strength and bending stiffness. Beams represent structures in which the cross-section is assumed to be small compared to the length. You can assign beam sections only to wire regions. In addition, you must assign a beam section orientation to all regions with beam sections.
Beam sections. Beam sections consist of a material name, a section Poisson's ratio, and a reference to a profile. Additional information is required depending on whether you choose to calculate (integrate) the section stiffness either before or during analysis.
For information on profiles, see “Defining profiles,” Section 12.2.2. For more information on beam sections, see “Creating beam sections,” Section 12.11.7.
Truss sections. Trusses, like beams, are used in two and three dimensions to model slender, rod-like structures that provide axial strength but no bending stiffness. Truss sections consist of a material name and cross-sectional area.
For more information, see “Creating truss sections,” Section 12.11.8.
Other sections
Other sections you can create include gasket sections, cohesive sections, acoustic infinite sections, and acoustic interface sections.
Gasket sections (ABAQUS/Standard analyses only). Gaskets model thin sealing components that are positioned between structural components. Gasket sections are used to provide pressure-closure behaviors for sealing components. Gasket sections consist of a material name, initial gasket thickness, initial gap, initial void, and cross-sectional area.
For more information, see “Creating gasket sections,” Section 12.11.9, and “Modeling gaskets,” Section 21.6.
Cohesive sections. Cohesive sections are used to model finite thickness adhesives, negligibly thin adhesive layers for debonding applications, as well as gaskets. No specialized gasket behavior (typically defined in terms of pressure versus closure) is available. Cohesive sections consist of a material name, response, initial thickness, and out-of-plane thickness.
For more information, see “Creating cohesive sections,” Section 12.11.10, and “Modeling adhesive joints and bonded interfaces,” Section 21.1.
Acoustic infinite sections. Acoustic infinite sections are used to model an acoustic medium undergoing small pressure changes involving exterior domains. Acoustic infinite sections consist of an acoustic medium material name. In addition, if the section will be used with a two-dimensional region, you must also specify the section thickness. (You have the option of specifying a plane stress or plane strain thickness even if the section will be assigned to a three-dimensional region. ABAQUS/CAE ignores the thickness information if it is not needed for the region type.)
For more information, see “Creating acoustic infinite sections,” Section 12.11.11.
Acoustic interface sections. Acoustic interface sections are used to couple an acoustic medium to a structural model. Acoustic interface sections consist of an acoustic medium material name. In addition, if the section will be used with a two-dimensional region, you must also specify the section thickness. (You have the option of specifying a plane stress or plane strain thickness even if the section will be assigned to a three-dimensional region. ABAQUS/CAE ignores the thickness information if it is not needed for the region type.)
For more information, see “Creating acoustic interface sections,” Section 12.11.12.
Warning: The type of section that you assign to a part must be consistent with the element type that you assign to instances of that part in the Mesh module. For example, if you assign a truss section to a wire part in the Property module, you should assign a truss element type (and not a beam element type) to any instances of that part in the Mesh module.