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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 40 for “"crack path"”.
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Crack Path Selection in Adhesively Bonded Joints
… is to obtain an overall understanding of the crack path selection in adhesively bonded joints. Using Dow Chemical epoxy resin DER 331® with various levels of rubber concentration as an adhesive, and aluminum 6061-T6 alloy with different surface pretreatments as the adherends, both symmetric …
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Crack path selection in microstructurally tailored inhomogeneous polymers
… that can help us experimentally study crack path selection problems. The model material which we are using is a polyethylene co-polymer, ECO, whose photosensitive behavior allows alterations in its mechanical properties when subjected to ultraviolet (UV) irradiation. It is seen that ECO …
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Crack Path Predictions Under Mixed Mode Loading In Aero-Structures: Measurements and Analysis
… conditions, the flaw is likely to undergo stable crack growth (SCG) in ductile materials. Understanding such fracture events in ductile materials is an important component of structural integrity analysis for ductile structures, especially since there are no general fracture criterion available to …
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Crack Path Bifurcation at a Tear Strap in a Pressurized Stiffened Cylindrical Shell
… The shell contained an initial, axial through-crack centered between the straps. The crack propagated slowly in the axial direction as the pressure increased above a certain value until a maximum pressure was attained, and then the crack propagated dynamically. The tear straps sufficiently …
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Crack path selection and shear toughening effects due to mixed mode loading and varied surface properties in beam-like adhesively bonded joints
… environmental challenges. In these situations, cracks can start within the adhesive layer or debonds can initiate near an interface. The paths taken by propagating cracks can affect the resistance to failure and the subsequent service lives of the bonded structures. The behavior of propagating …
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Laboratory evaluation of cracking in asphalt concrete
Cracking is one of the major distresses in asphalt concrete leading to high maintenance and rehabilitation costs throughout the nations pavement infrastructure. Asphalt concrete is a three phase, heterogeneous composite consisting of aggregate, mastic, and air voids. Crack initiation, crack path …
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Numerical study of solder joint failure under fast loading conditions
… evolution leading to eventual failure through crack formation. Attention is devoted to deformation under relative high strain rates (1-100 s-1), mimicking those frequently encountered in drop and impact loading of the solder points. The effects of applied strain rate and loading mode on the …
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Fatigue crack propagation in functionally graded materials
Propagation of cracks in functionally graded materials (FGMs) under cyclic loading was investigated via experiments and finite element (FE) analysis. Alumina-epoxy composites with an interpenetrating-network structure and tailored spatial variation in composition were produced via a multi-step …
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Effect of temperature on the fracture behavior of lead-free solder joints
… The load-displacement behavior corresponding to crack initiation and the subsequent toughening before ultimate failure and the displacements near crack tip are recorded and used to calculate the fracture energy release rates. The fracture surfaces and the crack path analyses are conducted with a …
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A Mesh Objective Algorithm for Modeling Mode-I Cracks Using a Standard Finite Element Formulation
… mesh objective algorithm for modeling mode-I cracks is developed and implemented within a standard finite element formulation. The algorithm applies the crack opening displacements across the standard nodal degrees of freedom that is consistent with formalism of the conventional smeared crack …
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Fracture Behavior of Masonry Bond
… process and the fracture process zone at the crack tip was small relative to plain concrete and mortar. This was due to the highly brittle fracture nature associated with pre-determined weak crack path and relatively smooth crack surfaces. Using the relationship between degree of bond and bond …
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Crack propagation in isotropic materials
This thesis presents a numerical study of crack propagation in brittle materials. The finite element method using constant strain triangular elements was used. The experimental investigation is based on Gurney and Hunt's quasi-static method of fracture testing.<br/><br/>The applicability of the …
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Mixed-Mode Crack Propagation in Functionally Graded Materials
The fracture parameters describing the crack tip fields in functionally graded materials (FGMs) include stress intensity factors (SIFs) and T-stress (non-singular stress). These two fracture parameters are important for determining the behavior of a crack under mixed-mode loading conditions in …
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Brittle Fracture in Oceanic Basalts
… wet at 20°c, and 300°c. Modal integration of the crack path length and general modal analyses indicate that regardless of texture or test parameter: (1) the fracture path seeks out voids, glass, and grain boundaries to the exclusion of mineral grain cleavage, (2) a propagating fracture is offset …
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Fatigue crack growth in polycrystalline alumina at high temperatures
High temperature crack growth behavior in a commercial and a hot-pressed polycrystalline Al$\sb2$O$\sb3$ was examined under monotonic tensile loading (static fatigue) and under Mode-I tension-tension cyclic loading (cyclic fatigue). The investigation of fatigue crack growth in polycrystalline …
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Potential-Based Fracture Mechanics Using Cohesive Zone and Virtual Internal Bond Modeling
… are used to reduce mesh bias and to improve crack path geometry represented by a finite element mesh. Adaptive mesh refinement and coarsening schemes are systematically developed in conjunction with edge-split and vertex-removal operators to reduce computational cost. Computational results …
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A continuum theory with long-range forces for solids
… is applicable off and on defects and interfaces: cracks and phase boundaries are a natural part of the body, and do not require special treatment. Furthermore, as the model loses "local stiffness", the resistance to the formation of discontinuities is reduced. The theory can be viewed in two ways: …
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Mathematical modeling of adhesive layer cracks utilizing integral equations
Within recent years, Crack analysis in adhesive layers has become a topic of interest for many researchers. A common model which is used incorporates a 3-region elasticity problem consisting of only 2 materials, the adhesive layer bounded by 2 layers of a stiffer elastic substrate. Cracks have been …
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Effect of oxygen potential on high temperature crack growth in alloy 617
The effect of oxygen partial pressure on crack growth rates in Alloy 617 has been studied using both static and fatigue loading at 650°C. Tests were conducted at a constant stress intensity factor, K, for static loading conditions or constant AK for fatigue loading using a direct current potential …
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Mechanism of Fatigue Crack Growth at Polymer/metal Interface
Fatigue crack growth along an Al/epoxy interface was examined under mixed-mode conditions. To provide different combinations of Mode-I and Mode-II conditions, a flexural peel (FP) technique was developed, which proved to be particularly useful for subcritical crack growth studies. Using this …
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