Structural Engineering Flashcards

A simply supported beam of span 8 m carries a uniformly distributed load of 10 kN/m. What is the maximum bending moment?

Answer: 80 kN·m

Maximum bending moment for a simply supported beam with UDL = wL²/8 = 10×8²/8 = 80 kN·m.

Which of the following best describes the condition of a 'statically determinate' structure?

Answer: Reactions and internal forces can be found using equilibrium equations alone

A statically determinate structure has exactly as many unknowns as equilibrium equations, so all reactions and internal forces can be solved without material properties.

In reinforced concrete design, the term 'balanced section' refers to:

Answer: A section where concrete crushing and steel yielding occur simultaneously

A balanced section is one in which the extreme concrete fiber reaches its crushing strain (0.003) at the same time the tension steel reaches its yield strain.

What is the slenderness ratio of a column, and which value typically indicates a 'long' (slender) column?

Answer: KL/r; values greater than 120 are typically considered long columns

Slenderness ratio = KL/r, where K is the effective length factor, L is column length, and r is radius of gyration; values above about 120 generally classify a column as slender.

According to limit state design philosophy, the ultimate limit state (ULS) is primarily concerned with:

Answer: Structural collapse or failure of the structure

The ultimate limit state addresses structural safety against collapse, including yielding, buckling, fracture, and overturning.

A cantilever beam of length 4 m carries a point load of 20 kN at its free end. What is the maximum shear force?

Answer: 20 kN

For a cantilever beam with a point load P at the free end, the maximum shear force equals P = 20 kN, occurring throughout the entire length.

Which structural system transfers loads primarily through axial tension or compression with negligible bending?

Answer: Truss

Trusses are designed so that all members carry purely axial (tensile or compressive) forces, with loads applied only at joints to minimize bending.