The New Science of Strong Materials – or why you don’t fall through the floor (book review)

Title :-The New Science of Strong Materials – or why you don’t fall through the floor.
By :- J.E. Gordon
Published :- Penguin books (1968-91) Paperback (280 pages)
Outline;- Material science looked at from under the microscope and from atomic structure explains why materials have various physical properties, and how that translates into design of structures. Reviews in easy to read aspects of metals, and non metals such as glass and wood.
Some interesting extracts;
• “The weakening effect of a scratch has very little to do with the material removed, a shallow scratch will do very nearly as a deep one, it is the sharpness of the re-entrant that increases the stress.”
• “It is well known that when a liquid freezes by crystallizing the crystals tend to expel impurities. For example ice that is formed on salt water is substantially fresh…This effect causes impurities in solids to accumulate at the grain boundaries (and also vacancies) and this may cause the grain boundaries to become a line of weakness. This is one of the reasons why the addition of quite small amounts of the wrong impurity can ruin an alloy.”
• “When the crack is very shallow it is consuming more energy than it is releasing as relaxed strain energy and therefore the conditions are energetically unfavorable for it to propagate. As the crack gets longer however these conditions reverse and beyond the critical “critical Griffith length” the crack is producing more energy than it is consuming, so it may start to run away in an explosive manner.”
• “A bond which is strained elastically is more susceptible to being dissolved chemically and physically. For this reason points of high stress are especially liable to attack by solvents or to corrosion by chemicals”.
• A foot note “ During the nineteenth century Edward G. Wakefield (1796- 1862) pointed out that an important obstacle to the colonization of Australia and New Zealand was the very low price of land. This, he showed, led to so wasteful a use of land that no colony could flourish. When, at his instigation, the price of unoccupied land was controlled and raised, colonization was successful.”