Crack closure integral

As there were some doubts about the validity of the crack closure integral in the dynamic case, a J-integral expression from Equation (4) was implemented in the FV program. Because it was found that the J-integral is mesh sensitive and requires a very fine mesh, a test case of a center... 

Fracture of polymers, viscoelasticity, crack growth initiation, finite element simulation, crack closure integral, thermomechanical reliability, rate dependence... 

To evaluate erack load in finite element simulations, a virtual crack extension was used Dubois et al. [9]. Xiong et al. [8] applied a modified crack closure integral to analyse viscoelastic effects on interfacid delamination. Both approaches lead to the same equations, whieh ean be generalised for the 3D case ... 

To evaluate G in finite element analyses it is well established to modify the crack closure integral (3) in a way introduced by Rybicki and Kanninen [13]. For 8-noded 2nd order elements a formulation is taken from [14] and extended to the 3D case [19]. 

The Figs.11-13 contain for the corresponding interface cracks at two neighbouring fibers the total strain energy release rate G =. T G. as well as the single parts G. (j = l,ll) where the latter were determined by the aid of Irwin s modified crack closure integral [15]. 

Energy release rate, impact test, Charpy, crack closure, finite volume, J integral. 

Zang W, 1990. Crack Kinks and Crack Closure Modelled by Integral Equation Methods. Doctoral thesis Royal Institute of Technology. Stockholm, Sweden. 

The simultaneous equations (17),(19) and (23) can be integrated step-by-step to give the variation of fi with a and hence, by equation (20), the variation of contact size with load. During loading (crack closure) = Pel given by equation (19) during... 

The elastic J-integral range AJei is estimated using a crack closure factor qw ... 

Dynamic J integral and crack tip closure for coarse mesh... 

Dynamic J integral versus crack tip closure for fine mesh... 

Vials are a little less prone to pinhole cracks than ampoules. They are usually more robust and are not deliberately weakened in particular areas to allow opening. The main concern with vials is the integrity of the seal between the vial itself and its elastomeric closure. 

Although the singularity in the above equation is integrable, Freund and Barnett (1976) developed a slip distribution associated with the smooth closure condition crack model (Bilby and Eshelby 1969) that has been used for... 

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