structures and why things don t fall down

Critical Griffith crack length is the point when a crack goes from being safe and stable to being self-propagating and very dangerous. ductile materials are those that, when pulled in tension, have stress-strain curves that depart from Hooke's law, after which the material deforms plastically (think chewing gum resiliance is the ability to store train energy and deflect elastically under a load without breaking/causing permanent damage a biscuit is stiff but weak, steel is stiff ad strong, nylon is flexible (not stiff / low E) and strong, raspbery jelly is flexible (not stiff / low E) and weak Strength is not the same thing as stiffness (e.g.

Hooke's law says that all solids change their shape - by stretching or contracting - when a mechanical force is applied to it, and it is this change of shape that allows an object to push back Young's modulous of elasticity ('E') = stress/strain Strength is the stress needed to break a material Strain is how far atams are being pushed or pulled Strain = e = increase of length / original length Stress measures how hard atoms in a material are being pulled apart or pushed together Streess = s= load / area = MegaNewtons / meter^2 These notes constitute about the first 175 pages, I should get around to documenting what I learned in the back half at some point. Much of what I write below is copied verbatim from the text, but am too lazy to identify what with appropriate quotes. The author is also hilariously British and doesn't waste an opportunity to rag on the French. What an incredible book! The best layman's introduction to a scientific topic that I've read since Feynman's QED.

Structures and why things don t fall down