Fracture Mechanics Applied to Brittle Materials

Abstract

This state-of-the-science publication on fracture test techniques for glass, ceramics, rocks, and cementitious composites is a compilation of 14 papers which were presented at the Eleventh National Symposium on Fracture Mechanics, which was held June 12-14,1978, at Virginia Polytechnic Institute and State University, Blacksburg, Va.These papers can be grouped into three categories: papers which relate to the theoretical and experimental details of test techniques; papers which describe the applications of these test techniques; and a paper which explains the use of fracture data in life time prediction of structural components.Although Griffith fracture theory was motivated by fracture of glass, its modern application to brittle materials is complicated by the unforgiving nature of such materials.Additional complication is introduced in the high temperature test environment of some structural ceramics.These unique test requirements promote the use of double torsion, notch bend, and short bar specimens which are discussed in detail by Fuller, Pletka, et al., Bansal, et al., and Barker.A unique ceramic fracture specimen which uses an indentation generated surface flaw in a bend specimen is discussed by Petrovic, et al., Marian and Evans.As for material characterization, dynamic fracture response of a birefringent polymer is discussed by Fourney, et al., and Mecholsky, et al., reported on ceramic fracture toughness obtained through fractographic analysis.Fracture toughness of alumina and Westerly granite are reported by Buresch and Schmidt, et al.The complex fracture behavior of cementitious composites is discussed by Naaman, et al.The last paper by Wiederhorn, et al, presents a fracture mechanics approach for improving the reliability of structural ceramics.As is the recent ASTM practice, this STP contains a thorough summary by the editor, S. W.