Important Notes on Structural Analysis (CEB 614)

Unit Information

  • Unit Code: CEB 614

  • Unit Title: Structural Analysis

  • Credit Points: 15

  • Instructor: Pawan Prasad (BE Civil, 1st Class Hons)

  • Lecture Hours: 4 hours/week

  • Tutorial Hours: 1 hour/week

  • Lab Hours: 2 hours/week

  • Self-directed Learning: 6-8 hours/week

  • Prerequisite: MEB 503 Engineering Mechanics

  • Contact: Email pawan.prasad@fnu.ac.fj

Types of Loads in Engineering Structures

  • Vertical Loads:

    • Dead Load: Permanent/static forces due to the structure's weight.

    • Live Load: Variable loads (e.g. occupancy).

    • Impact Load: Forces from dynamic actions (e.g. moving vehicles).

  • Horizontal Loads:

    • Caused by earthquakes and winds.

  • Longitudinal Loads:

    • Result from tractive or braking forces (e.g. gantry girders, bridge beams).

Structural Analysis

  • Determines effects of different loads on structural elements (e.g. beams, columns).

  • Structural Elements Include:

    • Foundations, beams, columns, walls, floors.

    • Not includes non-bearing elements (doors, windows).

Types of Loading on Beams

  1. Point Load: Applied at a single point on the beam.

  2. Uniformly Distributed Load (UDL):

    • Magnitude constant across the beam.

    • Convert to point load: W = wL acting at midpoint.

  3. Uniformly Varying Load (UVL):

    • Magnitude varies uniformly along the beam.

    • Convert to point load: W = \frac{1}{2} wL at center of gravity (1/3 from base).

  4. Couples: Two equal and opposite forces creating a bending moment M = F(d).

Types of Beams

  1. Simply Supported Beam:

    • Rest on supports at both ends, free to rotate.

  2. Cantilever Beam: Supported at one end.

  3. Fixed Beam: Both ends fixed, preventing rotations.

  4. Continuous Beam: Rest on more than two supports.

Free Body Diagram (FBD)

  • Visual representation of all forces acting on the structure.

  • Useful for calculating unknown variables (force direction, magnitude).

Equilibrium in Structures

  • Structures are in equilibrium when \sum Fx=0, \sum Fy=0, \sum M=0.

  • Each force must balance out for static condition.

Analysis of Stability

  • Truss Stability:

    • m + r < 2j o Unstable

    • m + r = 2j o Stable & Statically Determinate

    • m + r > 2j o Stable & Statically Indeterminate.

  • Frame Stability:

    • Compares members, joints, and reactions using similar rules.

Shear and Moment Diagrams

  • Relate to forces and moments acting on beams.

  • Key to identifying maximum moments and failure points in beams.

  • May use semi-graphical methods for plotting diagrams based on area calculations.