13th International Conference on Fracture June 16–21, 2013, Beijing, China -2- suggesting a modal decomposition, but limiting his work to the mode 0 N = . It is suggested here to extend the modal analysis to higher vibration modes to investigate the dynamic crack growth and arrest in a DCB specimen. 2. The Bernoulli beam model applied to a duplex DCB. An elastic Double Cantilever Beam specimen is illustrated in the figure 1. The specimen arms are slowly prescribed to a monotonic opening displacement 0( ) W t which gives rise to a quasi-static mode I crack growth (denoted by the current value 0 c ≤ < l l l ) in a first part of the beam, made up of a 0 2Γ surface energy material. A second material with a lower toughness, denoted the test section, is welded to the first one (the corresponding surface energy is 1 0 2 2 Γ < Γ ). When the crack tip reaches the critical point corresponding to the sections interface ( c x =l ) where the toughness jump occurs, its rapidly runs throughout the test section, while the loading is frozen. The crack velocity l& (and the arrest length A l ) in this test section, is governed by the surface energy ratio of the two sections ( 0 1 / , 1 R R =Γ Γ > ). We investigate here the crack kinematics during this stage, including the crack arrest c A x ≤ ≤ l l , with the assumption of a straight crack path, without any branching or kinking. Figure 1 Crack growth and arrest in a bimaterial DCB specimen. Only half of the specimen, and then half of the surface energy ( 0 1 , Γ Γ ) are considered here. A Bernoulli-Euler model is assumed to model the beam (the ratio / c h l is considered small enough 0 A 0( ) W t y x Crack arrest point Material interface sharing the starting and the test section ( , ) w x t 2h Critical crack length c beginning the dynamic process 0 2Γ 1 0 2 2 / R Γ = Γ Crack path in the test section
RkJQdWJsaXNoZXIy MjM0NDE=