Unit 2 - Materials and Structures (2.1 - 2.3)

What is the centroid of a shape?

The centroid is the center of mass of a shape and is useful for finding moments of inertia.

What is the formula for the moment of inertia for a rectangular beam?

The formula is I = (b × h^3) / 12, where b is the base width and h is the height.

How do you calculate the maximum deflection of a simply supported beam?

The formula is δ = (F × L^3) / (48 × E × I), where F is the force, L is the length, E is the modulus of elasticity, and I is the moment of inertia.

What are free body diagrams (FBDs) used for?

FBDs are used to visualize the forces acting on a body.

How do you resolve a force into its components?

Use the formulas: F_x = F × cos(θ) and F_y = F × sin(θ).

What is the method of joints used for?

The method of joints is used for solving forces in truss members by applying equilibrium equations (ΣF_x = 0, ΣF_y = 0) and using FBDs.

What are materials?

Materials are substances from which all things are made, with over 120,000 unique types.

How are elements classified?

Elements are classified based on their properties, such as metals, non-metals, and metalloids.

What are the properties of metals?

Metals conduct heat and electricity, are hard, shiny, and reflective.

What characterizes non-metals?

Non-metals are dull, brittle, poor heat conductors, with tightly packed electrons.

What are metalloids?

Metalloids exhibit properties of both metals and non-metals.

What is a compound?

A compound is a substance formed when elements chemically combine.

What is a mixture?

A mixture is a non-chemical combination of substances.

What are the classifications of metallic materials?

Metallic materials conduct thermal and electrical energy, are malleable and ductile.

What is vulcanization?

Vulcanization is a process that forms strong bonds between polymers, enhancing strength and elasticity.

How are materials recycled?

Materials are recycled through methods specific to organics, metals, polymers, ceramics, and composites.

What do material disposal codes provide?

Material disposal codes provide a systematized body of laws to guide the proper disposal of materials.

How is stress calculated?

Stress (σ) is calculated as Force / Area and is measured in Pascals (Pa).

What units are used for strain?

Strain is measured in in/in or mm/mm.

What is the modulus of elasticity?

The modulus of elasticity (E) is the ratio of stress to strain.

What does a stress-strain diagram illustrate?

It illustrates the relationship between stress and strain, highlighting the elastic region, yield point, plastic region, ultimate tensile strength, and fracture point.