Structural Engineering Flashcards
Explain the difference between determinate and indeterminate structures and how it influences structural analysis.
Determinate structures can be analyzed using equilibrium equations alone, as all unknown forces can be determined, while indeterminate structures require additional compatibility equations due to the presence of redundant members, increasing the complexity of structural analysis.
Discuss the fundamental principles of virtual work and its application in structural analysis.
The fundamental principles of virtual work involve the concept that the external work done on a structure is equal to the internal strain energy accumulated, providing a powerful method for solving indeterminate structural systems by considering virtual displacements and applying the principle of virtual work.
Define the load factor and resistance factor in structural design and explain their roles in ensuring safety.
The load factor represents the factor by which various loads are multiplied to account for uncertainties and variability, while the resistance factor is applied to structural capacities to provide a margin of safety, collectively ensuring safety in structural design by addressing uncertainties in loads and material strengths.
Discuss the concept of serviceability in structural design and its importance.
Serviceability in structural design refers to the acceptable performance of a structure under normal usage conditions, addressing aspects such as deflections, vibrations, and durability, and is crucial for ensuring user comfort, functionality, and long-term structural integrity.
Explain the purpose and behavior of shear walls in building structures.
Shear walls in building structures serve the purpose of resisting lateral loads, such as those from wind or seismic forces, by providing stiffness and strength, effectively distributing these loads and enhancing the building’s overall stability.
Explain the concept of flexural reinforcement and its role in enhancing the strength of reinforced concrete elements
Flexural reinforcement in reinforced concrete elements involves the addition of steel bars to withstand bending moments, enhancing the tensile strength of the structure and preventing brittle failure by allowing for ductile behavior and redistribution of loads.
Explain the concept of effective length in the design of steel columns
Effective length in the design of steel columns represents a measure of their stability, considering the end conditions and the potential for lateral-torsional buckling, influencing the determination of critical buckling loads and appropriate design provisions.
Define the terms “lateral-torsional buckling” and “slender column” and discuss their significance in structural stability.
Lateral-torsional buckling is the mode of instability involving both lateral bending and twisting experienced by slender columns, and their significance lies in the potential for this buckling mode to compromise the stability of structural members under axial loads, requiring careful consideration in design to prevent structural failure.
Discuss the factors influencing the choice between shallow and deep foundations in structural design.
The choice between shallow and deep foundations in structural design is influenced by factors such as the type and magnitude of loads, soil characteristics, site constraints, and economic considerations, determining the most suitable foundation system for supporting the structure.
Weight of unreinforced normal concrete
145 lb/ft^3
Weight of reinforced normal concrete
150 lb/ft^3
How to find factored load
Step 1: Find weight of beam with W=baseheightweight. If in kips divide by 1000. Add W to DL to get final DL. First do 1.2DL and then 1.4DL+1.2LL. Whichever is larger rules
How to find factored moment
Find uniform factored load. Then go to the table at the end of the M.O.M section and find which beam and load type you’re solving for and use Max moment eqn.
Determinate Structure
of Reactions = 3 * # of beams
