Structural Flashcards
What is span in structural design?
Span is the distance a structural element covers between supports.
Why is ductility important in structural materials?
Ductile materials like steel bend before breaking, offering warning before failure.
What happens when a material is brittle?
It can fail suddenly without warning under stress.
What is deflection in a beam?
Deflection is the downward displacement of a beam under load.
Why is deflection a concern?
Excessive deflection can damage attached materials like glass or masonry.
What factors influence beam deflection?
Load, span length, material (E), and shape (I).
What is buckling in columns?
Buckling is the sudden lateral failure due to axial compression.
What factors affect buckling?
Load magnitude, column height, bracing, and slenderness (KL/r).
How does bracing affect buckling?
Bracing reduces the effective length, reducing buckling risk.
What is bridging in joists?
Bridging connects joists to prevent lateral buckling and spread loads.
What is the purpose of a shear wall?
Shear walls resist lateral loads and prevent the building from racking.
What is a pinned connection?
A connection that allows rotation but transfers vertical loads.
What is a moment connection?
A rigid connection that resists rotation and transfers moments.
Why use pinned instead of moment connections?
Pinned connections are cheaper and easier to construct.
What is a one-way structural system?
Loads are carried in one direction, e.g., joists spanning between two walls.
What is a two-way structural system?
Loads are carried in two directions, e.g., a concrete slab spanning both ways.
Why are continuous beams used?
They reduce deflection by creating upward moments over supports.
What are the two major factors in structural design?
Material (modulus of elasticity E) and shape (moment of inertia I).
How does shape affect structural strength?
Greater depth increases the moment of inertia and reduces deflection.
What is the role of E and I in beam deflection?
They appear in the denominator of the deflection formula, reducing deflection when increased.
What is tributary area?
The area of load that contributes to the force on a structural element.
Why is tributary area important?
It determines the total load a structural member must support.
What is the load transfer order in a structural frame?
Decking → Joists → Beams → Girders → Columns.
How do you decide girder vs beam direction?
Girders usually span the shorter distance and carry more load.
