DOUBLE TORSION METHOD AND ITS USE FOR MECHANICAL PROPERTIES EVALUATION OF BRITTLE MATERIALS
双扭法及其在脆性材料力学性能评定中的应用

The double torsion method(DT)for mechanical properties eva-luation of brittle materials has been presented.It is shown that DT method hassuch advantages as wide material adaptability and extensive study contents sinceits stress intensity factor(K_1)at crack tip has nothing to do with crack length(a).In this paper some use for DT method in electrical porcelains Si_3N_4,PMMA.and GCr15 steel have been made and discussed.A new formula for DT specimenstress intensty factor has been suggested and some advise for suitabie region ofcrack length has been proposed on using DT method.