Structural Systems Overview

• Structural systems are categorized based on their geometric shape.

Structural System Classifications

• Linear: Straight like columns, beams, frames, or curved like arches.
• Surface planar: Flat like solid or hollow slabs, or curved in one or two directions.
• Spatial linear: Straight like space trusses, or curved in one or two directions.
• Spatial surface: Flat like folded slabs, or curved like intersecting vaults.

Spatial Structures

• Spatial structures are defined as a system of interconnected elements that do not lie in a single plane.

Main Stresses

• Axial forces (N) include tension and compression.
• Shear forces are denoted as Qx and Qy.
• Torsional moment is represented by T.
• Bending moments are denoted as Mx and My.

Linear System Structural Elements

• Common linear structural elements are tie rods, struts, and columns.

Structural Elements Subjected to Bending Moments

• Simple beams (horizontal), cantilevers, and continuous beams are structural elements subjected to bending moments in linear systems.

Structural Elements Subjected to Axial Forces and Bending Moments

• Column and beam assemblies, frames, and Vierendeel trusses are structural elements subjected to axial forces with bending moments in linear systems.

Stresses in Curved Linear

• Arches experience axial compressive forces.

Tie Rod

• A tie rod is a structural member subjected only to tension.
• Tie rods can be independent or part of a larger structure like a truss.
• Materials can be solid or flexible, such as metal cables.
• Materials can be single or double resistance like metal, wood, or reinforced concrete.
• Tie rods have small cross-sections relative to their length.

Strut

• A strut is a structural member that is subjected only to compression.
• Struts can be independent or part of a larger structure like a truss.
• Struts are always solid.
• Materials can be single or double resistance like metal, wood, or reinforced concrete.
• Struts have small cross-sections relative to their length.

Column

• A column is a structural member subjected to compressive forces only.
• Material can be single or double resistance (metal, wood, or reinforced concrete)
• Columns have small cross-sections compared to their length.
• They can be solid or hollow, with various shapes.

Cantilever

• A cantilever is a linear structural member that experiences bending moments at the support point.
• Cantilevers are supported on one end via a fixed connection.
• The maximum moment is at the fixed end, and the moment is zero at the free end.
• Materials can be single or double resistance like metal, wood, or reinforced concrete.
• A thickness-to-span ratio for reinforced is 1/5, and for steel 1/25.
• A cantilever with a 5 meter span would have a Im drop.
• The thickness of the cantilever can be reduced towards the free end as bending moment decreases.