Structural Engineering Concepts

• Amplification Factor

  • Multiplier of moment/deflection in unbraced axially loaded member.
  • Reflects secondary values from axial load eccentricity.

• Beam

  • Structural member that carries loads transverse to its longitudinal axis.

• Beam-Column

  • Structural member that carries loads both transverse and parallel to its longitudinal axis.

• Bent

  • Plane framework of beam/truss members supporting loads.
  • Includes the columns supporting these members.

• Biaxial Bending

  • Simultaneous bending about two perpendicular axes.

• Braced Frame

  • Frame where lateral load/instability resistance comes from diagonal/K-braces or bracing system.

• Brittle Fracture

  • Abrupt cleavage with little/no prior ductile deformation.

• Buckling Load

  • Load at which straight member under compression deflects.

• Built-up Member

  • Member of structural metal elements connected by welds, bolts, or rivets.

• Chevron Bracing

  • Bracing form with a pair of braces located above/below a beam terminating at a single point in clear beam span.

• Cladding

  • Exterior covering/structural components of a building.

• Cold-Formed Members

  • Structural members formed from steel without heat.

• Column

  • Structural member carrying loads parallel to its longitudinal axis.

• Column Curve

  • Curve showing relationship between axial column strength & slenderness ratio.

• Combined Mechanism

  • Mechanism from plastic analysis, combining beam, panel, & joint mechanisms.

• Compact Section

  • Sections developing fully plastic stress distribution.
  • Rotation capacity ~3 before local buckling.

• Composite Beam

  • Steel beam structurally connected to a concrete slab for unified load response.

• Composite Column

  • Steel column from rolled/built-up shapes encased in concrete or from steel pipe/tubing filled with structural concrete.

• Concrete-Encased Beam

  • Beam fully encased in concrete cast integrally with the slab.

• Connection

  • Combination of joints transmitting forces between members.
  • Classified by force transferred (moment, shear, end reaction).

• Critical Load

  • Load at which bifurcation occurs from theoretical stability analysis.

• Curvature

  • Rotation per unit length due to bending.

• Design Strength

  • Resistance (force, moment, stress) provided by element/connection.
  • Product of nominal strength and resistance factor.

• Diagonal Bracing

  • Inclined members carrying axial load enabling truss-like frame action for horizontal load resistance.
  • Diagonally connects joints at different levels.

• Diaphragm

  • Floor slab, metal wall, or roof panel with high in-plane shear stiffness/strength for horizontal force transmission.

• Diaphragm Action

  • In-plane action of a floor system maintaining relative position of columns above and below the floor

• Double Curvature

  • A bending condition causing a member to assume an S-shape.

• Drift

  • Lateral deflection of a building.

• Drift Index

  • Ratio of lateral deflection to building height.

• Ductility factor - The ratio of total deformation at maximum load to the elastic-limit deformation

• Eccentric Braced Frame (EBF)

  • Diagonal-braced frame with a bracing member connecting to a beam a short distance from a beam-to-column/beam-to-brace connection.

• Effective Length

  • Equivalent Length KL used in compression formulas. Determined via Bifurcation Analysis.

• Effective Length Factor K

  • Ratio between effective length and unbraced length of member between gravity centers of bracing members.

• Effective Moment of Inertia

  • Moment of inertia of cross-section that remains elastic during partial plasticization, usually under combined residual and applied stress.

• Effective Stiffness: Stiffness using the effective moment of inertia.

• Effective Width

  • Reduced width of plate/slab with uniform stress distribution producing same effect as actual plate width with non-uniform distribution.

• Elastic Analysis

  • Determination of load effects (force, moment, stress) on members/connections. Bases on the assumption that material deformation disappears on removal of the force that produced it.

• Elastic-Perfectly Plastic

  • Idealized stress-strain curve.
  • Varies linearly from zero strain/stress up to yield stress, then increases in strain at yield stress without further stress increase.

• Embedment

  • Steel component cast in concrete to transmit external loads into the concrete structure. Achieved via bearing, shear, bond, friction, or combination thereof.

• Encased Steel Structure

  • Steel framed structure with some frame members encased in concrete.

• Euler Formula

  • Mathematical relation for Euler load value. Relates modulus of elasticity, moment of inertia, and column length.

• Euler Load

  • Critical load of perfectly straight, centrally loaded, pin-ended column.

• Eyebar

  • Pin-connected tension member with uniform thickness. Forged/same cut head with greater width, proportioned for equal strength in head and body.

• Factored Load

  • Product of nominal load and load factor.

• Fastener

  • Generic for welds, bolts, rivets, or other connecting means.

• Fatigue

  • Fracture from fluctuating stress cycle.

• First-Order Analysis

  • Analysis based on first-order deformations. Equilibrium conditions are formulated on the undeformed structure.

• Flame-Cut Plate

  • Plate with longitudinal oxygen cut edges.

• Flat Width

  • For rectangular tube, nominal width minus twice outside corner radius.
  • Absence of corner radius knowledge: total section width minus three times thickness.

• Flexible Connection

  • Connection allowing partial simple beam rotation at member end.

• Floor System

  • Structural components separating building stories.

• Force

  • Resultant of stress distribution over area.
  • Reaction that occurs in a member as a result of applied load formerly called axial stress.

• Hybrid Beam

  • Fabricated steel beam. Flanges have a larger yield strength that the web.

• Inelastic action - Material deformation does not disappear on removal of the force that produced it.

• Instability - loading an element or structure in which continued deformation results in a decrease of load-resisting capacity.

• Joint - Area where ends, surfaces, or edges are attached and categorized by type of weld used and method of force transfer.

• K-Bracing - System of struts, resembling the letter K, used in a braced frame, which can be located on the X or Y plane

• Lateral bracing member - A member utilized individually or as a component of a lateral bracing system to prevent buckling of members elements and/or to resist lateral loads.

• Lateral (or lateral-torsional) buckling - Buckling of a member involving lateral deflection and twist

• Limit state - A condition in which a structure for its intended function

• Limits states - Limits of structural usefulness excessive deformation, durability, fatigue, instability.

• Link Beam - The part of a beam in an eccentrically braced frame which is designed to yield shear and/or bending so that buckling of the bracing members is prevented

• Load factor - A factor that accounts for unavoidable deviations of the actual load from the nominal value and for uncertainties in the analysis.

• Loads - Forces on structural systems indirect structural system changes.

• LRFD (Load and Resistance Factor Design) - proportioning structural components

• Local buckling - element which may precipitate the failure of the whole member.

• Nominal loads - The magnitudes of the loads specified by the applicable code.

• Panel zone - The zone in a beam-to-column connection that transmits moments by a shear panel and is constructed in a composite beam for which the shear strength of shear connectors governs the flexural strength.

• Partially shear connectors - developed to support shear and tension

• Plane frame - A structural system assumed for two dimensional

• Plate girder - A built-up structural beam.

• Post-buckling strength - load that can be carried by an element

• Redistribution of moment - a steel section in a circular shape

• Required strength - appropriate)

• Residual strength - after it has been formed.

• Resistance factor - unavoidable deviations

• Rigid frame - beam and column members

• Root of the Flange - flange or flange-to-web weld

• Second Order Analysis - deformations and forces of a new design project

• Service Load - often taken as the nominal load.

• Serviceability limit state - structure to preserve its appearance

• Shape Factor - modulus for a cross section.

• Shear-friction- in concrete that transmits shear loads.

• Shear lugs - Plates,

• Shear wall - A wall that

• Sidesway - external forces

• Sidesway Buckling - displacements of joints,

• Single curvature - a reversal.

• Slender Section - buckling in the elastic range.

• Slenderness ratio - with respect to bending.

• Slip critical joint - required.

• Space Frame -

• Splice-longer member.

• Stability limit load - are included.

• Stepped Column - length of the column

• Stiffner - or preventing buckling of the member to which it is attached

• Stiffness - corresponding displacement

• Story Drift - A story

• Strain Hardening - or well above yield point exhibits the capacity to resist substantially higher loading than that initial yielding

• Strain Hardening Point - hardening

Explore key concepts in structural engineering: beam-columns, braced frames, amplification factors, biaxial bending, compact sections, and composite beams. Understand resistance factors, chevron bracing, rigid frames, hot-rolled vs. cold-formed steel, and second-order analysis. Learn about serviceability limit states.