initial cracks occur in high strength concrete sleepers for various reasons, such as shrinkage and wrong curing and long lifetime of over 50 years of sleepers. these cracks may lead to complete failure of the structure. in order to more accurately design the sleepers, fracture mechanics (not strength of materials) should be incorporated. in order to achieve this purpose, it is important to fore...

An analytical method is being developed to determine the signature of an acoustic emission waveform from a growing crack and the results of this analysis are compared to experimentally obtained values. Within the assumptions of linear elastic fracture mechanics, a two dimensional model is developed to examine a semi-infinite crack that, after propagating with a constant velocity, suddenly stops...

The stress field at the tip of a crack of a thin plate of elastic material that is broken due to a mode III shear tearing has a universal form with a nonuniversal amplitude, known as the stress intensity factor, which depends on the crack length and the boundary conditions. We present in this paper exact analytic results for this stress intensity factor, thus enriching the small number of exact...

We investigate the validity of the linear elastic fracture mechanics approach to dynamic fracture. We first test the predictions in a lattice simulation, using a formula of Eshelby for the time-dependent stress intensity factor. Excellent agreement with the theory is found. We then use the same method to analyze the experiment of Sharon and Fineberg. The data here are not consistent with the th...

In this paper, we introduce an implementation of the extended finite element method for fracture problems within the finite element software ABAQUSTM. User subroutine (UEL) in Abaqus is used to enable the incorporation of extended finite element capabilities. We provide details on the data input format together with the proposed user element subroutine, which constitutes the core of the finite ...

Recently the authors have derived various new types of path independent integrals in which the theoretical limitations of the so-called J integral are overcome. First, for elastodynamic crack problems, a path independent integral J' which has the physical meaning of energy release rate was derived. Later, more general forms of path independent integrals T* and T were derived, which are valid fo...

In order to characterize the fatigue behaviour and determine the fracture energy of polysilicon used in micro-systems, an on-chip testing device has been designed and fabricated. The experimental set-up is able to continuously measure the elastic stiffness decrease and therefore to evidence fatigue of polysilicon 15-μm thick films and to allow for the introduction of a sharp crack at the notch ...

Additive manufacturing is unquestionably gaining importance in industry. Due to the layer by deposit process, it usually leads an anisotropic material. A question of whether Linear Elastic Fracture Mechanics can be used assess their resistance fracture. In this paper, we investigate point on polycarbonate printed Fused Deposition Modelling focusing a criss-crossed pattern. Thanks tensile and fr...

A probabilistic methodology has been developed for fracture-mechanics analysis of nonlinear cracked structures. The methodology involves nonlinear ®nite element analysis using well-known commercial codes; statistical models for uncertainty in material constitutive law, fracture toughness, and loads; and standard reliability methods for evaluating probabilistic characteristics of elastic±plastic...