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...

Concrete is a so called quasibrittle material which, despite predominantly elastic material response, exhibits in tension loading a stable non-linear fracture response, when tested under displacement control. The reason for the non-linearity is the development of a fracture process zone, in front of the crack, due to micro-cracking and crack bridging. The effect of the fracture process zone is ...

This work investigates fracture characteristics of a marble semi-circular bend (SCB) specimen with pre-defined crack under compressive loading condition. It aims at evaluating how the toughness can be affected by and span length variation. Numerically, model is solved using meshless methods, extended to linear elastic mechanics (LEFM), resorting radial point interpolation method (RPIM) its natu...

Temperature dependent fracture properties of NiTi-based Shape Memory Alloys (SMAs), within the pseudoelastic regime, were analyzed. In particular, the effective Stress Intensity Factor (SIF) was estimated, at different values of the testing temperature, by a fitting of the William's expansion series, based on Digital Image Correlation (DIC) measurements. It was found that temperature plays an i...

Small-scale cohesive-zone models based on potential functions are expected to be consistent with the important features of linear-elastic fracture mechanics (LEFM). These include an inverse-square-root K-field ahead a crack, normal and shear stresses being proportional mode-I mode-II stress-intensity factors, KI KII, work done against crack-tip tractions equal KI2+KII2?E?, where E? is appropria...

In the framework of Cost Action CERTBOND (Reliable roadmap for certification bonded primary structures), a wide group researchers from 27 European Countries have had opportunity to work on topic joints structural applications different engineering sectors such as aerospace, automotive, civil engineering, wind energy and marine sectors. Since virtual testing optimization are basic tools in proce...

This work demonstrates numerically how microplasticity, i.e. the yielding behavior below conventional 0.2% plastic strain threshold, can lead to initiation of cracks at subsurface defects, in rolling contact applications operating under realistic loads. A 3D elasto-plastic finite element model is employed perform shakedown analysis bearing steel around a small spherical void with two different ...

This paper considers the explicit solutions of free-edge stresses near circumferential cracks in surface coatings of circular torsion bars and their application in determining the progressive cracking density in the coating layers. The problem was formulated within the framework of linear elastic fracture mechanics (LEFM). The free-edge stresses near crack tip and the shear stresses in the cros...

modelling of crack propagation by finite element method under mixed mode conditions is of prime importance in fracture mechanics. this paper describes an application of finite element method to the analysis of mixed mode crack growth in linear elastic fracture mechanics. crack growth process is simulated by an incremental crack-extension analysis based on the maximum principal stress criterion,...

Many engineering materials of importance can be mechanically characterized as brittle or quasi-brittle solids. Examples include many hard polymers, ceramic composites, and low ductility metals. Fracture toughness is the measure crack extension a function applied load resistance deforming material to advance cracking. In this investigation we use digital image correlation (DIC) for observing stu...