Element action effects

For the inelastic frame element type employed in the structural model, there can be three kinds of Element action effects results (subdivided into three categories), which are described in detail hereafter.

Frame Deformations
The deformations incurred by inelastic (infrmFB, infrmFBPH, infrmDBPH, infrmDB) frame elements, as computed in their local co-rotational system of reference, are provided. The values refer to the chord rotations at the end-nodes of each element (referred to as A and B, as indicated in here), the axial deformation and the torsional rotation. Finally, the maximum, minimum and absolute maximum values may be displayed on the selected graph.

Frame Forces
The internal forces developed by inelastic (infrmFB, infrmFBPH, infrmDBPH, infrmDB) frame elements, as computed in their local co-rotational system of reference, are provided. The values refer to the internal forces (axial and shear) and moments (flexure and torsion) developed at the end-nodes of each element, referred to as A and B (see in here). The possibility of obtaining the cumulative, rather than the distinct, results of each element can be very handy when a user is interested in adding the response of a number of elements (e.g. obtain the shear at a particular storey, given as the sum of the internal shear forces of the elements at that same level). Further, the maximum, minimum and absolute maximum values may be displayed on the selected graph.

Frame Hysteretic Curves
Hysteretic plots of deformation vs. internal forces developed by inelastic (infrmFB, infrmFBPH, infrmDBPH, infrmDB) frame elements, as computed in their local co-rotational system of reference, are provided. The maximum, minimum and absolute maximum values may be diplayed on the selected graph.

  1. Rotational degrees-of-freedom defined with regards to a particular axis, refer always to the rotation around, not along, that same axis. Hence, this is the convention that should be applied in the interpretation of all rotation/moment results obtained in this module.
  2. Element chord-rotations output in this module correspond to structural member chord-rotations, allowing the direct employment of element chord rotations in seismic code verifications (see e.g. Eurocode 8, Italian National Seismic Code NTC-18, Greek Seismic Interventions Code KANEPE, etc).
  3. Under large displacements, shear forces at base elements might well be different from the corresponding reaction forces at the supports to which such base elements are connected to, since the former are defined in the (heavily rotated) local axis system of the element whilst the latter are defined with respect to the fixed global reference system.
  4. SeismoBuild does not automatically output dissipated energy values. However, users should be able to readily obtain such quantities through the product/integral of the force-displacement response.