Structural Mechanics Lecture 2

A structure is a collection of interconnected elements designed to transfer loads between points.

Permanent loads are always present on a structure, like its own weight.

Live loads are temporary loads that are not always present, like people, vehicles, or wind.

Extreme loads are rare forces that cause significant stress on a structure, like earthquakes or tsunamis.

Static loads are constant forces that don't change over time, like the weight of a building.

Dynamic loads are forces that change over time, like wind gusts or earthquake shaking.

Structural engineers must design structures to perform their intended function while meeting safety requirements.

Structures should meet at least two performance objectives: functionality and safety. They must be effective and safe to use.

The ability of a structure to withstand extreme loads without collapsing, ensuring stability and sufficient strength.

The ability of a structure to function under normal use, minimizing excessive deflection and vibration.

A vector quantity representing both magnitude (size) and direction. It is measured in Newtons (N), where 1 N = 1 kg.m/s2.

The amount of matter in an object. It is measured in kilograms (kg).

The force of gravity acting on an object's mass. It is calculated by multiplying mass and acceleration due to gravity (g = 9.81 m/s2).

The study of objects at rest, not in motion. It involves understanding the forces acting on a stationary body.

A component of a structure, defined by its length, cross-section shape, and area. It can be of various shapes and sizes.

The area of a structural element's cross-section. It is important for determining the strength and load-carrying capacity of the element.

The tendency of a force to cause rotation around a point.

The state where the sum of all moments acting on an object equals zero.

Forces that act in the same plane.

Forces acting through the same point cannot cause rotation.

Forces that do not act through the same point can cause rotation.

Forces that act on the boundary of a structure, including applied forces and support reactions.

A force acting perpendicular to the cross-section of a structural element.

A force acting parallel to the surface of a structural element.

A body at rest where the sum of all forces acting on it equals zero. This means the body is not moving or accelerating.

A force that tends to cause rotation around a point.

A force that acts along the axis of a structural element, either pulling it apart or pushing it together.

The distance from the point of rotation to the point where the force is applied.

A structure where all internal forces can be determined using equations of equilibrium alone.

A force that acts on a structural element, causing it to bend or deform.

The force per unit area acting on a structural element, caused by internal forces.

The change in length or shape of a material due to applied stress.

The slope of the stress-strain curve in its linear elastic region, indicating the stiffness of the material.

The point on the stress-strain curve where the material begins to deform permanently.

The stress at which a material breaks or fails.

The ability of a material to deform plastically before fracturing.