Specifying properties for beam sections integrated during analysis

Beam sections integrated during analysis allow the cross-sectional behavior to be calculated by numerical integration of the stress over the cross-section to define the beam's response as the analysis proceeds. The material behavior is evaluated independently at each point on the section. This type of beam section should be used when the section nonlinearity is caused only by nonlinear material response. For more information, see Using a Beam Section Integrated during the Analysis to Define the Section Behavior.

  1. From the main menu bar, select SectionCreate.

    A Create Section dialog box appears.

    Tip: You can also click Create in the Section Manager or select the create section tool in the Property module toolbox.

  2. Enter a section name. For more information on naming objects, see Using basic dialog box components.
  3. Select Beam as the section Category and Beam as the section Type, and click Continue.

    The beam section editor appears.

  4. Choose During analysis as the Section integration method.
  5. Select a profile for the beam section. If desired, click to create a profile; see Creating profiles, for more information.

    The Profile shape field is updated to reflect your choice.

  6. On the Basic tabbed page:
    1. Select a Material name to be used with this beam section definition. If desired, click to create a material; see Creating and editing materials, for more information.
    2. Enter a value for the Section Poisson's ratio to provide uniform strain in the section due to strain of the beam axis (so that the cross-sectional area changes when the beam is stretched). This value must be between −1.0 and 0.5. A value of 0.5 will enforce incompressible behavior.
    3. Select a method for defining the Temperature variation through the section:

      • Choose Linear by gradients to indicate that the temperature at the cross-section origin and the temperature gradient or gradients through the section are specified. You can use the Load module to specify these temperatures.

      • Choose Interpolated from temperature points to indicate that the shape of the beam section profile determines the number and location of the temperature points. (For more information on temperature points, see Beam Cross-Section Library.) You can use the Load module to specify the temperature at each of these points.

  7. On the Stiffness tabbed page, do the following:
    1. Select Use consistent mass matrix formulation to let Abaqus calculate the mass formulation for the beam section using the McCalley-Archer consistent mass matrix based on the cubic interpolation of deflections and quadratic interpolation of rotations. If you toggle off this option, Abaqus performs this calculation using a lumped mass formulation.
    2. Toggle on Specify transverse shear to include nondefault transverse shear stiffness effects in the section definition and specify the Slenderness compensation:

      • Select Use analysis product default to let Abaqus calculate the shear stiffness and the slenderness compensation factor from the elastic material definition for the beam section.

      • Select Value to specify the transverse shear stiffness effects directly.

        • Enter a slenderness compensation factor in the field provided.

        • Enter values for the K23 and K13 shear stiffnesses of the section in the fields provided.

  8. On the Fluid Inertia tabbed page, toggle on Specify fluid inertia effects to simulate the inertial effects of the beam being submerged in a fluid. For details, see Additional Inertia due to Immersion in Fluid.
    1. Specify whether the beam is Fully submerged or Half submerged in the fluid. If you select Half submerged, the added inertia per unit length is reduced by a factor of one-half.
    2. Specify the Fluid density.
    3. Enter the effective radius of the wetted cross-section in the Section radius field.
    4. Specify CA, the added mass coefficient for Lateral motions of the beam.
    5. Specify CA-E, the added mass coefficient for Motions along beam axis.
    6. If the beam cross-section origin is different than the centroid of the wetted cross-section, specify the centroid's X and Y coordinates relative to the cross-section origin.
  9. Click OK to save your changes and to close the beam section editor.