The paper deals with the energy release rate G of nonlinear double cantilever beam (DCB) specimens. Often the equivalence of the basic definition G = - (1/ B)¿H /¿l (B: width of the specimen, H: Helmholtz energy, I: crack length) and the expression G* = (l/B)¿W /¿l (W: elastic energy) is assumed. The validity of this assumption is investigated. It is concluded that for the nonlinear DCB specimen the two expressions are not equivalent so that the basic definition for G should be used. The paper further comments upon an article  in which nonetheless G* is used for the nonlinear DCB specimen and, contrary to expectation, good agreement with experimental data is obtained. The reason for this agreement is indicated.
|Number of pages||5|
|Journal||Zeitschrift fuer Metallkunde|
|Publication status||Published - 1997|