ENGG1700 Statics & Materials - Statics Summary Revision Notes

Flashcards for reviewing key concepts from ENGG1700 Statics & Materials lecture notes.

Force

A vector quantity defined by magnitude, direction, and line of action/point of application.

Principal of Transmissibility

A force can be applied at any point along its line of action without changing its effect on the body as a whole.

Moment

Force x Perpendicular Lever Arm

Couple

A moment caused by equal & opposite parallel but non-collinear forces

Equilibrium

When a body is in EQUILIBRIUM, the sum of ALL the forces (applied loads and reactions) is zero; AND The sum of the moments is also zero.

Free Body Diagram (FBD)

Shows ALL the forces acting on the body in equilibrium. This means all APPLIED FORCES and REACTIONS

Equations of Condition

Additional equilibrium equation when the structure has some unique feature eg internal pin or hinge

Stability

Arrangement to ensure equilibrium for typical loading. Can a small force cause large displacements?

Determinancy

If Number of unknowns (reactions) = Number of INDEPENDENT equilibrium equations THEN the structure is DETERMINATE and we can solve for all the unknowns by hand.

Point Load

Concentrated force applied at a single point.

Uniformly Distributed Load (UDL)

Load that is evenly distributed across a length.

Triangular Load

Load distribution that varies linearly along a length.

Truss

A structure consisting of usually a triangulated arrangement of members.

Pin-jointed planar trusses

Members are connected by pins. Only internal forces that exist are AXIAL forces.

Sign convention

Axial force where tension is positive and compression s negative.

Internal Forces

Shear Force, Axial Force, Bending Moment

SFD, BMD, AFD

Diagrams showing Shear Force, Bending Moment, and Axial Force along a beam or frame.

First Moment of Area

Used to locate the centroid of a shape.

Second Moment of Area

Used to calculate resistance to bending and buckling.

Parallel Axis Theorem

Relates Second Moment of Area about centroidal axis to a parallel axis.

Hooke’s Law

States that stress is proportional to strain for an elastic material.

Neutral Axis

The stress at E’F’ is ZERO.