Structural Analysis and Design-I Flashcards

Vocabulary flashcards reviewing structural determinacy, stability, truss classifications, cables, arches, and influence lines based on lecture notes.

Determinate Structure

A structure in which all reaction and internal forces can be determined using equations of static equilibrium alone, requiring no additional compatibility equations.

Indeterminate Structure

A structure whose reactions and internal forces cannot be completely determined using equilibrium equations alone, requiring additional compatibility of deformation equations.

External Stability

The stability of an entire structure against external movement, depending mainly on the number and arrangement of supports to prevent overall rigid body movement.

Internal Stability

The stability of members and joints within a structure, depending on their geometrical arrangement and connectivity to prevent changes in internal shape.

Geometrically Stable Structure

A structure whose stability depends mainly on the geometrical arrangement of members and joints, ensuring it cannot change its shape under loading.

Statically Stable Structure

A structure whose stability depends mainly on the number and arrangement of support reactions to provide sufficient external restraints against rigid body motion.

Plane Truss

A truss in which all members and joints lie in a single plane, and external loads act within that same plane.

General Cable Theorem

A theorem stating that at any point on a cable acted upon by vertical load, the product of the horizontal component of cable thrust $H$ and the vertical distance $y$ equals the bending moment $M_x$ in a simple supported beam of identical span and loading.

Two-Hinged Arch

An arch structure statically indeterminate to the first degree with four unknown reaction components, having hinges at each support base, and sensitive to temperature changes and support settlement.

Three-Hinged Arch

A statically determinate arch structure with three hinges (one at each support and one at the crown), which is insensitive to temperature changes and unaffected by support settlement.

Influence Line

A graph showing the variation of a structural reaction, shear force, bending moment, or member force at a specific section as a unit load moves across the span of the structure.

Normal Thrust

The total axial compressive force acting perpendicular to the cross-section of an arch rib, expressed as $N = H \tan(\theta) + V \tan(\theta)$ or $N = H \tan(\theta) + V \tan(\theta)$.

Radial Shear

The shear force acting parallel to the cross-section of an arch rib, expressed as $V_r = V \tan(\theta) - H \tan(\theta)$.