Fundamentals of Structural Engineering and Mechanics

Fundamentals of Structures

What is a structure?

A structure is a group of elements united to support a load.

What is a force?

A force is anything that can deform a body or modify its state of rest or movement.

What is a load?

Loads are the forces that a structure must bear.

Types of structural loads

Loads are categorized as either fixed or variable.

What is an effort?

An effort is the internal force experienced by the elements of a structure when subjected to external forces.

Types of structural efforts

The primary efforts are: Tension, Compression, Shear, Torsion, and Bending.

Conditions for a stable structure

A structure must possess three key conditions: rigidity, stability, and resistance.

• Rigidity: Achieved through triangulation.
• Stability: Achieved by widening the base or placing braces.
• Resistance: Achieved by building beams with structural profiles.

Types of structures

• Frame Structure: (e.g., Buildings) Easy to design and build, but less effective for very large loads.
• Shell Structure: (e.g., Natural: eggs; Artificial: cars) Maintains shape and supports loads; can be thin because forces are spread throughout the structure.
• Arch: (e.g., Roman Arch) Displaces forces to the sides; requires support for lateral thrust.
• Mass Structures: (e.g., Natural: mountains; Man-made: walls) Held in place by their own weight; heavy and space-consuming.
• Suspension Structure: (e.g., Suspension bridge) Excellent for covering large spans, but expensive to construct.

Structural elements in a house

Typical elements include: Columns, Primary beams, Secondary beams, and Foundations.

Unions between structural elements

Unions are classified as either permanent or non-permanent.

Strengthening elements

The effectiveness of strengthening depends on the types of forces applied, the points of application, the shape of the structure, and the materials used.