Understanding How Components Fail by Donald J. Wulpi is one of those rare texts that takes a complex subject and makes it understandable to the layman while preserving that complexity. The book is, as the title suggests, an examination of the types of failures that mechanical components undergo and how to examine those failures. The book covers distortion failures, fractures of so many types, stresses, wear, corrosion, and high-temperature failures.
The many pictures allow you to look at your own failed component and see what type of failure occurred. If you find yourself constantly wondering why you have broken parts, this might be a helpful book — likewise if you seek to avoid having broken parts! There is no math but each chapter ends with a long bibliography for further research.
The book has a “limited” preview on Google Books should you wish to see what’s inside. The book is fairly expensive but you can find cheap copies from time to time. It’s certainly a candidate for inter-library loan.