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Showing 1 to 20 of 33 for “"Damage modes"”.
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Healing of complex damage modes in model composites
… for composites poses a challenge as many damage modes occur during composite failure including matrix cracking and fiber-matrix debonding. In this thesis, a tow-level model composite test is developed with a view towards simplifying characterization and improving understanding of …
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Limits of Permissible Damage in Strong-Post W-Beam Guardrail
… of new guardrail. The risk posed by minor damage modes, e.g. small deflections and missing posts, has never been evaluated. Using finite element models validated by real world crash tests, this study assessed the safety risk of crashes into guardrail with minor damage. The minor damage …
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Lengthscale effects in the damage and failure of composites
… and identify lengthscale effects associated with damage in composite materials and their structures, and to determine how these lengthscales vary across levels of composites and can be used in assessing the overall response of composite structures. This is an advancement in a much larger pursuit …
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Damage states in laminated composite three-point bend specimens - an experimental/analytical correlation study
Damage states in laminated composites were studied by considering the model problem of a laminated beam subjected to three-point bending. A combination of experimental and theoretical research techniques was used to correlate the experimental results with the analytical stress distributions. The …
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Compression of thick laminated composite beams with initial impact-like damage
… for many years. the complexity of the damage initiated by low velocity impact has not lent itself to simple predictive models for compression strength. The damage modes due to non-penetrating. low velocity impact by large diameter objects can be simulated using quasistatic three-point …
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Damage analysis and mechanical response of as-received and heat-treated Nicalon/CAS-II glass-ceramic matrix composites
Experimental results of damage development in and mechanical response of heat-treated NicaloniCAS-II laminates subjected to monotonic flexure and axial loading and to cyclic tensile loading are reported. The specimens were subjected to post-processing heat treatments at 900°, 1000°, and l100°C in …
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Probabilistic aspects of progressive damage in composite structures
… probabilistic aspects of the progression of damage in the analysis of composite structures are assessed. Two specific cases of graphite/epoxy with centrally-located holes are considered: a [0/90/±45], laminate subjected to equal biaxial tension, and a [±15/0],, laminate subjected to uniaxial …
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Characterization of damage mechanisms and behavior in two-dimensionally braided composites subjected to static and fatigue loading
… and fatigue loading conditions to determine damage mechanism types and progressions. The braided architectures consisted of straight axial fiber bundles, which were surrounded by braider fiber bundles oriented at ±a 0 with respect to the axial fiber bundles. Static tension and compression …
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Damage accumulation of bovine bone under chaotic and variable amplitude loading.
… type. PSW has shown it is able to identify damage modes of fatigue. Therefore, further investigation into the prediction capabilities of PSW should be pursued.
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Damage accumulation of bovine bone under chaotic loading.
… was able to successfully identify the various damage modes and may be a viable tool for predicting the fatigue life of bone. As such, PSW is worth further research. Many more tests need to be completed to obtain statistical significance.
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Impact Simulation and Analysis of Sandwich Structures
<p>Impact damage on aircraft and spacecraft can be a severe problem that may cause catastrophic results. Several aerospace structures have been used to resist or absorb energy in the occasion of impact. Among these, a sandwich structure has advantages with high stiffness, strength to weight ratio, …
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Self-healing of impact damage in vascular fiber-reinforced composites
… self-healing technologies. To date, the critical damage modes which occur during out-of-plane impact that most significantly contribute to reductions in post-impact performance have not been identified and methods for delivering healing agents to those critical regions using internal vascular …
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Damage Development in Static and Dynamic Deformations of Fiber-Reinforced Composite Plates
… delamination between adjoining layers, and damage due to fiber breakage, fiber/matrix debonding, and matrix cracking. The three damage modes are modeled using the theory of internal variables and the delamination by postulating a failure envelope in terms of the transverse stresses; the …
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The effects of properties, microstructure and phase transformation on the erosion of hard materials
… physical and mechanical properties. The damage modes are described for the two types of erosion and the results are critically discussed. It has been shown that different properties and microstructural features control the respective types of erosion. Hardness is the critical property …
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Stiffness reduction resulting from transverse cracking in fiber- reinforced composite laminates
Several damage modes, including fiber breakage, delamination, and transverse cracking, have been observed to contribute to the mechanical degradation of fiber-reinforced composite laminates. In this investigation, the effect of transverse cracking on laminate stiffness was studied. Four. …
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Analytical model for force prediction when machining metal matrix composites
… reinforcement particles are the considerable damage modes that directly influence the tool performance. It is very important to find highly effective way to machine MMCs. So, it is important to predict forces when machining Metal Matrix Composites because this will help to choose perfect tools …
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Adaptive learning for event modeling and pattern classification
… to make the fuzzy classification of blade engine damage modes among a group of engines containing historical flight data after Principal Component Analysis (PCA) is applied to reduce the excessive dimensionality. This approach can be effectively used to deal with classification of patterns with …
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An anisotropic damage model for rock
An anisotropic damage model is proposed for the constitutive description of microcracking processes in brittle rock under a general loading path. Experimental data and micromechanical models are reviewed to quantify the effect of microcracking on the material stiffness and the mechanisms of …
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Monitoring Progressive Damage Development in Laminated Fiber Reinforced Composite Materials
… of growing importance in engineering practice. Damage development in composite materials is more complex than for metallic materials, because in composite materials (a) multiple damage modes are simultaneously in play, and (b) individual 'damage events' that occur throughout a component's …
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Behavior of Reinforced Concrete Panels Subject to Impact by Non-deformable Projectiles
… resistance and itseffect on the nature of local damage caused by impact of non-deformable projectiles are investigated. The investigation included a combination of 53 experiments and series of finite-element based numerical simulations. Three levels of local damage modes were investegated based …
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