Thirteen sections, nearly twenty concept pairs — stress vs. pressure, yield vs. ultimate strength, fatigue vs. creep, torque vs. horsepower, resonance vs. natural frequency, and more — each worked with a concrete example and the exact confusion it resolves in the field.
Module 2 covered what engineering materials are. This module covers why parts made from them behave the way they do — the conceptual distinctions that separate someone who can read a material spec sheet from someone who can predict how a shaft, bracket, or pressure vessel will actually respond under a static load, a million load cycles, or a temperature swing. Every one of these pairs gets confused constantly on real design reviews and shop floors, and every one of them has a concrete, practical consequence when it's gotten wrong.
This is the hallmark module of the entire program. Everything from Module 4's mechanics through Module 16's troubleshooting scenarios and all five real-project case studies leans on the distinctions built here — fatigue and factor of safety surface again in the Module 13 reliability content, torque vs. horsepower returns at full scale in the Module 6 power-transmission deep-dive, and resonance comes back concretely in the project-05 HVAC mechanical room case study.