Showing papers in "Theoretical and Applied Fracture Mechanics in 2018"

TL;DR: In this paper, a phase field model (PFM) is presented for simulating complex crack patterns including crack propagation, branching and coalescence in rock, based on the strain decomposition for the elastic energy, which drives the evolution of the phase field.

TL;DR: In this paper, the authors analyzed the relationship between the monotonic and cyclic behavior of cylindrical AlSi10Mg (CL31 AL) samples fabricated by Selective Laser Melting (SLM) to the build direction, the presence of manufacturing defects (pores, voids, oxides, etc.) and the beneficial effect of post-processing (T6 and hot isostatic pressing (HIP) treatments).

TL;DR: In this paper, the dynamic tensile strength and dynamic elastic modulus of UHPC material were determined using a high-speed photograph system and a subsequent fractographic analysis was performed using the extended finite element method.

TL;DR: In this paper, an epoxy matrix incorporated with hybrid multi-walled carbon nanotube (MWCNT) and nanosilica was used to fabricate woven carbon fabric epoxy composites using vacuum-assisted resin infusion molding.

TL;DR: In this paper, a new approach for determination of tensile strength ft and fracture toughness KIC of concrete using wedge-splitting (WS) specimens is presented, which considers the influence of coarse aggregate structures on concrete fracture by linking the fictitious crack growth Δafic at peak load Pmax to the maximum aggregate size dmax.

TL;DR: In this paper, a review of brittle and ductile crack growth under both monotonic and cyclic loadings using the XFEM was given from both macro-scale and micro-scale after a systematic literature survey.

TL;DR: In this paper, the effect of CNTs agglomeration on the fracture toughness of polyurethane nanocomposites has been investigated, and a theoretical model was developed to predict the fracture-toughness of nanocom composites reinforced with well-dispersed carbon nanotubes (CNTs).

TL;DR: In this paper, the authors investigated the effect of shape and type of cohesive law, crack path location, length of damage process zone, variations of adhesive and FRP properties, and different failure modes including cohesive, interfacial debonding and fiber-reinforced polymer failure on the strength of joints.

TL;DR: In this article, an experimentally verified analytical approach for determining the entropy generation is presented that illustrates how the concept of fracture fatigue entropy can be applied to analyze both low and high-cycle fatigue.

TL;DR: In this paper, the authors investigated the relationship between the frequency of the released stress wave and the effective elastic modulus of the medium in the crack-tip region and the size of the crack source.

TL;DR: In this paper, a contour method and neutron diffraction measurements were also conducted on a compact tension sample extracted from the large structural welded mock-up, typical of the weldment used in offshore wind monopiles.

TL;DR: In this paper, the authors used Styrene Acrylonitrile (SAN) nanofibers, produced by the electrospinning method, to improve the out-of-plane and impact properties of a conventional carbon fiber/epoxy composite.

TL;DR: In this paper, a mixed mode I/II micromechanical bridging model was proposed based on the calculation of the delamination crack bridging zone energy absorption. And the results show that the proposed model is able to predict the mixed mode II/III delamination behavior of laminated composites considering fiber bridging effects.

TL;DR: In this article, a fracture criterion for ductile metals is developed, which is composed of two competing and correlated sub-criterions corresponding to the stress states where the shear fracture and tensile fracture modes can be captured.

TL;DR: In this paper, the authors evaluated the fracture properties and fracture parameters of EPS concrete with different volume percentages (0, 10, 20, 30, and 40%) and two water-to-cement ratios (0.4 and 0.5) and showed that the apparent density, tensile strength, compressive strength, elasticity modulus and ultrasonic waves velocity of EPScrete decrease when the volume fraction of EPS increases.

TL;DR: In this paper, the multiaxial fatigue behavior of circumferentially notched specimens made of titanium grade 5 alloy, Ti-6Al-4V, has been analyzed.

TL;DR: The scaled boundary finite element formulation enables accurate computation of the stress intensity factors directly from the stress solutions without any special post-processing techniques or local mesh refinement in the vicinity of the crack tip.

TL;DR: Zhang et al. as discussed by the authors presented a simple fracture model linking average grain size of granite to tensile strength ft and fracture toughness KIC, which only requires the peak load Pmax measurements of small notched samples to determine both ft and KIC.

TL;DR: In this article, mixed-mode dynamic stress intensity factors (DSIFs) for two-dimensional (2D) elastic cracked solids are evaluated employing ordinary state-based peridynamics (OSPD) theory.

TL;DR: In this article, a novel method of the time-dependent reliability, which combines the perturbation series expansions with the interval mathematics, is presented for life prediction of fatigue crack growth problems.

TL;DR: In this article, a simple damage healing law is proposed based on a time-dependent healing variable which represents the opposite of the damage variable, and applied on an isotropic concrete material at the macro-scale under tensile load.

TL;DR: In this paper, rheological, mechanical and thermal properties of the silica aerogel-epoxy nanocomposites were investigated, and the results of dynamic mechanical along with the thermal analysis showed that the addition of 6 wt% of silica Aerogel causes the storage modulus and glass transition point (Tg) to be increased by 11% and 5 °C, respectively.

TL;DR: In this paper, the influence of the bedding plane orientation on rock breakages in biaxial states was investigated, and it was shown that the increase in bedding planes restrained the propagation of both internal and surface cracks, leading to the shrinkage of grooves.

TL;DR: In this article, an extended maximum tangential strain criterion considering effect of first nonsingular strain term, as well as the singular strain terms, was employed to predict the fracture test data.

TL;DR: In this article, a new model based on thermodynamic entropy approach is proposed to predict the fatigue life of cross-ply laminates, which can discriminate between different stacking sequences in fatigue loading and also is sensitive to the frequency of loading and different ambient temperature.

TL;DR: In this paper, the fracture behavior of nanocomposite adhesives produced by adding nanostructure in to the adhesive was investigated using Double Cantilever Beam (DCB) test under ambient temperature and thermal cycle conditions, and it was observed that there is a significant difference between the displacements obtained directly from the test machines stroke and measured via video extensometer giving the crack opening between the top and bottom adherends during the DCB test.

TL;DR: In this paper, the effect of elevated temperature on the crack initiation life of Al7075-T6 under cyclic normal contact loading was investigated by experiment using a new testing apparatus.

TL;DR: In this paper, two numerical approaches are used to reproduce the experimental observations: a cohesive zone model (CZM) and the interfacial thick level set (ITLS) model.

TL;DR: In this article, the tensile behavior of a dual-phase Ti-6Al-4V alloy was investigated and the influences of stress triaxiality, strain rate and temperature were characterized.

TL;DR: In this article, the mixed-mode fracture behavior of C 50/60 concrete was studied both experimentally and theoretically using two different test configurations (three-point bending and Brazilian disc tests with various crack lengths).