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The purpose of this paper is to describe the development of an embedded crack finite element (FE) model for reinforced concrete (RC) structures, including a bond‐slip methodology to take into consideration the steel contribution in the rupture process, capable of capturing the global behavior of the structure as well as details of cracking phenomenon.

The reinforcement contribution is added in the equilibrium at element level in an embedded crack FE model, based on displacement localization lines inside the elements.

The model is able to determine the steel stress in the crack besides the volumetric average steel stress. It is shown that the steel stress in the crack can be considerable greater than the average value. Other important aspect detected is the contribution of the concrete softening in the steel stress in the crack and in the overall behavior. The number, the distribution and the opening of cracks can be estimated too.

The yield of the steel in the cracking process can be detected more precisely by this methodology, allowing a better design and understanding of RC structures. In addition, the knowledge of crack openings is an important information to predict corrosion and other degradation phenomena of the reinforcement bars.

The bond‐slip procedure is linked with the embedded crack model in an original way: sliding gives the crack width. Moreover, the inclusion of steel forces in the crack equilibrium balance was not a usual procedure and permits an understanding of reinforcement effect in both levels (macro and micro) studied in this work.

Gas permeability through damage networks in composite laminates is the key issue for the applicability of high‐performance composites to the cryogenic propellant tanks of space launch vehicles. A simple model for the gas permeability induced by multilayer matrix cracks in composite laminates is proposed based on the leak conductance at crack intersections, which is an extension of the model by Kumazawa et al (AIAA J. 41, 2037‐ ‐2044, 2003). Experimental evidence on the gas permeability mechanisms is summarized and reflected in the present model. In order to include the effects of applied loadings and damage sizes on the gas permeability, the leak conductance is assumed to be a function of the average crack opening displacements of the matrix cracks and the crack intersection angles. The leak conductance factor was empirically obtained as a function of the crack intersection angle, and the comparison of the gas permeability between the predictions based on the developed model and the experimental results is presented for the validity of this model.

The purpose of this paper is to investigate damaging processes in TaN thin film absorbers under action of high-voltage electrical pulse of nanosecond duration. Despite having mechanical origin of crack opening, estimation based on the readings from oscillograms shows uncharacteristically high velocities of the crack propagation.

Microscopic images of damaged absorbers showing the final result of the damaging process provided initial information about its geometrical peculiarities. Then, to clarify the dynamics of the process, the authors create the model of the crack, having elements of self-similarities and multiple stage opening. The influence of heating induced by current concentration at crack tip and of magnetic stress of this concentrated current are both included in the model.

Using physical parameters of TaN layers with flowing current and performing calculations the authors define the conditions required to initiate the damaging process and to sustain it. Danger of such damage is relevant for high-T_c superconducting thin films after their switching to normal state which is induced by the high-voltage pulse.

There were made recommendations to manufactures aiming to improve electrical durability of the absorbers in an effort to prevent the damaging influence of power nanosecond electrical pulses.

Three stage opening model implies the appearance of zone of high-energy dissipation that can lead to detonation-like destruction of the film and, therefore, explain the high velocities of crack propagation.

The purpose of this paper is to introduce the double-periodic lattice, composed of bending-resistant fibers. The essence of the model is that the filaments are of infinite length and withstand tension and bending. The constitutive equations of the lattice in discrete and differential formulations are derived. Two complementary systems of loads, which cause different deformation two orthogonal families of fibers, occur in the lattice. The fracture behavior of the material containing a semi-infinite crack is investigated. The crack problem reduces to the exactly solvable Riemann-Hilbert problem. The solution demonstrates that the behavior of material cardinally depends upon the tension in the orthogonal family of fibers. If tension in fibers exists, opening of the crack under action of loads in two-dimensional lattice is similar to those in elastic solid. In the absence of tension, contrarily, there is a finite angle between edges at the crack tip.

The description of stress state in the crack vicinity is reduced to the solution of mixed boundary value problem for simultaneous difference equations. In terms of Fourier images for unknown functions the problem is equivalent to a certain Riemann-Hilbert problem.

The analytical solution of the problem shows that fracture behavior of the material depends upon the presence of stabilizing tension in fibers, parallel to crack direction. In the presence of tension in parallel fibers fracture character of two-dimensional lattice is similar to behavior of elastic solid. In this case the condition of crack grows can be formulated in terms of critical stress intensity factor. Otherwise, in the absence of stabilizing tension, the crack surfaces form a finite angle at the tip.

Linear behavior of fibers until rupture. Small deflections. Perfect two-dimensional lattice.

The model provides exact analytical estimation of stresses on the crack tip as the function of fibers’ stiffness.

The model is the extension of known lattice models, taking into account the semi-infinite crack in the lattice. This is the first known closed form solution for an infinite lattice model with the crack.

From the practical point of view, most relevant damage to high density polyethylene (HDPE) structures is caused by slow crack growth. Therefore, detailed information about this type of damage is necessary. Experimental results transfer from specimens to real structure can be influenced by structure geometry (constraint). Therefore, the purpose of this paper is to investigate and discuss the effect of the constraint and relation between crack mouth opening displacement (CMOD) and crack length.

The constraint effect is mainly effect of the structure geometry and can be quantified by T‐stress. Two different test specimens with different constraint level (T‐stress) were prepared: single edge notched specimen and modified single edge notch (SEN) specimen. The crack mouth opening displacement, crack tip opening displacement and crack length was measured.

The main conclusions of this work can be summarized as: the slow crack growth rate in HDPE materials corresponds to velocity of CMOD; the influence of the presented specimen geometry on slow crack growth rate can be considered as negligible; and for transfer of the experimental results from specimens to real structure the influence of the structure geometry (constraint) is not critical.

Experimental results obtained from different specimens with different constraint level are rare and can lead to better data transfer from experimental specimens to the real structures.

The purpose of this paper is to investigate the fracture properties of hybrid woven bamboo (WB)/woven e-glass (EG) fiber composites with various layer arrangements. This paper utilized a specific type of bamboo species named Gigantochloa Scortechinii (Buluh Semantan).

In these experiments, unsaturated polyester, woven EG and WB fibers were prepared through the hand lay-up technique. The composite bamboo strips were prepared in 1.5 mm thickness. The strips are woven to make a single layer. The layer was then laminated into several thicknesses. The specimens were then characterized using compact tension fracture tests.

The fracture toughness of 12–14 MPa was obtained. These findings suggest that this hybrid bamboo composite provides superior fracture strength that is equivalent with steel alloy and is extremely a good alternative for reinforcing fibers to combat fracture failures of materials and structures.

In this paper, experimental determination of newly developed composite made of WB and woven EG is presented.

The purpose of this paper is to present a new bond slip model for reinforced concrete structures. It consists in an interface element (3D) which represents the interface between concrete (modeled in 3D) and steel, modeled using 1D truss elements.

The formulation of the interface element is presented and verified through a comparison with an analytical solution on an academic case. Finally, the model is compared with experimental results on a reinforced concrete tie.

Contrary to the classical perfect or “no-slip” relation which supposes the same displacement between steel and concrete, the proposed model is able to reproduce both global (force-displacement curve) and local (crack openings) results.

The proposed approach, applicable to large-scale computations, represents a valuable alternative to the no-slip relation hypothesis to correctly capture the crack properties of reinforced concrete structures.

The purpose of this paper is to evaluate some numerical integration strategies used in generalized (G)/extended finite element method (XFEM) to solve linear elastic fracture mechanics problems. A range of parameters are here analyzed, evidencing how the numerical integration error and the computational efficiency are improved when particularities from these examples are properly considered.

Numerical integration strategies were implemented in an existing computational environment that provides a finite element method and G/XFEM tools. The main parameters of the analysis are considered and the performance using such strategies is compared with standard integration results.

Known numerical integration strategies suitable for fracture mechanics analysis are studied and implemented. Results from different crack configurations are presented and discussed, highlighting the necessity of alternative integration techniques for problems with singularities and/or discontinuities.

This study presents a variety of fracture mechanics examples solved by G/XFEM in which the use of standard numerical integration with Gauss quadratures results in loss of precision. It is discussed the behaviour of subdivision of elements and mapping of integration points strategies for a range of meshes and cracks geometries, also featuring distorted elements and how they affect strain energy and stress intensity factors evaluation for both strategies.

To provide a reinforced concrete model including bonding coupled to a classical continuum damage model of concrete, capable of predicting numerically the crack pattern distribution in a RC structure, subjected to traction forces.

A new coupling between bonding model and an alternative model for concrete cracking is proposed and analyzed. For concrete, proposes a damage‐like material model capable of combining two types of dissipative mechanisms: diffuse volume dissipation and localized surface dissipation.

One of the most important contributions is the capacity of predicting maximal and minimal spacing of macro‐cracks, even if the exact location of cracks remains undetermined. Another contribution is to reiterate on the insufficiency of the local damage model of concrete to handle this class of problems; much in the same manner as for localization problem which accompany strain‐softening behavior.

Bonding becomes very important to evaluate both the integrity and durability of a RC structure, or in particular to a reliable prediction of crack spacing and opening, and it should be integrated in future analysis of RC.

Shows that introduction of the influence of concrete heterogeneities in numerical analysis can directly affect the configuration of the crack pattern distribution. Use of a strong discontinuity approach provides additional cracking information like opening of macro‐cracks.

Failure of the materials occurs once the stress intensity factor (SIF) overtakes the material fracture toughness. At this level, the crack will grow rapidly resulting in unstable crack growth until a complete fracture happens. The SIF calculation of the materials can be conducted by experimental, theoretical and numerical techniques. Prediction of SIF is crucial to ensure safety life from the material failure. The aim of the simulation study is to evaluate the accuracy of SIF prediction using finite element analysis.

The bootstrap resampling method is employed in S-version finite element model (S-FEM) to generate the random variables in this simulation analysis. The SIF analysis studies are promoted by bootstrap S-version Finite Element Model (BootstrapS-FEM). Virtual crack closure-integral method (VCCM) is an important concept to compute the energy release rate and SIF. The semielliptical crack shape is applied with different crack shape aspect ratio in this simulation analysis. The BootstrapS-FEM produces the prediction of SIFs for tension model.

The mean of BootstrapS-FEM is calculated from 100 samples by the resampling method. The bounds are computed based on the lower and upper bounds of the hundred samples of BootstrapS-FEM. The prediction of SIFs is validated with Newman–Raju solution and deterministic S-FEM within 95 percent confidence bounds. All possible values of SIF estimation by BootstrapS-FEM are plotted in a graph. The mean of the BootstrapS-FEM is referred to as point estimation. The Newman–Raju solution and deterministic S-FEM values are within the 95 percent confidence bounds. Thus, the BootstrapS-FEM is considered valid for the prediction with less than 6 percent of percentage error.

The bootstrap resampling method is employed in S-FEM to generate the random variables in this simulation analysis.