Manual on Experimental Methods of Mechanical Testing of Composites
by C.H. Jenkins (ed.)

Publisher:  Society for Experimental Mechanics
ISBN:  0881732842

The Manual on Experimental Methods of Mechanical Testing of Composites fills a gap in composite testing literature. Rather than covering the mechanics of ASTM and other standard tests, it instead focuses on general techniques such as the measurement of strain and the detection of damage in composites.

The chapters on traditional strain gages have the greatest detail and are the closest to a true manual. Guidelines are given for the selection of gage types, S-T-C numbers (as close to 0 as possible) and gage configurations. The effects of gage-fiber misalignment, material anisotropy, material nonuniformity (local flaws, textile weaves, braids) and low thermal conductivity are all explained.

Noticeably absent are instructions for actually bonding the gages to laminates. A single paragraph covers this subject in a later chapter on creep testing, but it really belongs in the gage chapters.

Coverage of other strain measurement methods -- liquid-metal gages, embedded fiber optics, moireacute, interferometry, shearography and thermography -- is rather mixed. Some of the chapters read almost like manuals, with specific instructions for applying the method. Others focus on the theory behind the method, saving the instructions for the recommended reading list. (Some of those references are entire books in themselves.)

The Manual on Experimental Methods of Mechanical Testing of Composites ends with four chapters on damage evaluation, both nondestructive (NDE) and destructive. Some of the strain field techniques, such as shearography and thermography, can also be used for NDE. In fact, these latter methods have the potential to differentiate between cosmetic and critical damage, something that can be done with ultrasonics or radiography only after extensive calibration testing.

Like many books written by a collection of authors, the writing is somewhat inconsistent from chapter to chapter and poor copy editing detracts from what is an otherwise excellent reference. Hardly a page goes by without a typographical error, grammatical error, mislabeled figure or even missing text.

By far the worst chapters are those on basic lamination theory. Hardly an equation goes by without an error and many are difficult to spot. I have to recommend ignoring those chapters altogether and referring to one of the many standard references on laminate analysis.

The frequency of errors diminishes as the book progresses (or maybe I just got tired of counting them). The Manual on Experimental Methods of Mechanical Testing of Composites has a lot of good information not covered in other testing books. As long as you are willing to read carefully and check equations, you will find this to be a useful reference.

Barry Berenberg, your Guide for Composite Materials