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Showing 1 to 20 of 24 for “"damage progression"”.
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Damage Progression in Open-Hole Tension Composite Laminates by the Element-Failure Method
Damage Propagation in composite laminates is traditionally modeled by the material property degradation method (MPDM), which assumes that a damaged material can be replaced by an equivalent material with degraded properties. In this thesis, a new damage-modeling technique known as the …
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Probabilistic aspects of progressive damage in composite structures
… of incorporating 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 …
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Development of Comprehensive Dynamic Damage Assessment Methodology for High-Bypass Air Breathing Propulsion Subject to Foreign Object Ingestion
… bird. Among the potential ingestion scenarios, damage caused by smaller objects may be considered to be negligible. Alternatively, larger objects can initiate progressive damage, potentially leading to catastrophic failure, compromising the integrity of the structure, and endangering the safety …
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The performance assessment of patch repaired and CFRP strengthened RC T-beams under transverse impact loading
… on many highways in South Africa. Structural damage due to such loading conditions requires repair and strengthening procedures that can return the structure to its original load bearing capacity. The use of patch repair mortar is common practice for the repair of impact damaged bridge beams …
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Investigation of Microcracking and Damage Propagation in Cross-Ply Composite Laminates
The present study investigates microcracking and damage progression in IM7/977-2, IM7/5555, and IM7/5276-1 [0/90/90/0] laminates. For each material system, seven to eight small coupons were axially loaded in a tensile substage. At increments of around 50 MPa the surfaces of the specimens were …
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Cavitation erosion of engineering materials
… have been evaluated. Detailed observation of damage progression in the above three classes of materials have been made. A comprehensive cavitation erosion test data base has been obtained. An appraisal on a comparative basis of the different erosion rates of the various material tested is …
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Performance of RC Bridge Columns under Cyclic Combined Loading including Torsion
… respect to strength, stiffness, deformation and progression of damage, and cause complex failure modes and in turn influence the overall behavior of the bridge system. This study performed experimental and analytical studies in order to investigate the performance of RC bridge columns under …
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Progressive damage and failure of unidirectional fiber reinforced laminates under impact loading with composite properties derived from a micro-mechanics approach
… and linear elastically. We have analyzed damage initiation, damage progression, and failure of 16-ply unidirectional fiber reinforced laminates impacted at normal incidence by a rigid sphere. The damage is assumed to initiate when at least one of Hashin's failure criteria is satisfied with …
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Development and applications of new peridynamic models
… equations, however, become troublesome when damage takes place. Instead of differential equations, this study presents a theory, so-called peridynamics, based on integral equations. Similar to molecular dynamics, peridynamics assumes that the domain of interest is organized by points. Each …
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A Comparison of Methods for Measuring Damage in Sucrose-Treated Medial Collateral Ligaments
… activities. When this loading is excessive, damage to the knee occurs leading to a decreased quality of life.The medial collateral ligament (MCL) is one of the 4 major ligaments known to be commonly injured in the knee. The risk of injury to the knee joint increases with the elderly and …
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Using the Finite Discrete Element Method (FDEM) to Correlate Simulated Microfractures to Acoustic Emissions in Brittle Anisotropic Rock
… both laboratory and numerical methods to track damage progression in brittle anisotropic rock at the laboratory specimen scale. For laboratory tests, AE are recorded during Unconfined Compressive Strength (UCS) tests on foliated metasedimentary rock from the Bathurst Mining Camp, New Brunswick, …
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Fretting fatigue Behaviour of Inconel 718 at room and high Temperature
… characterise the material's response to fretting damage. To this end, a cylindrical contact configuration was used, consisting of a rectangular cross-section "dog-bone" specimen pressed against a cylindrical pad. The setup was assembled using a device commonly referred to as a “fretting bridge.” …
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Three-dimensional boundary element and experimental analysis of lubricant ceramic surface ring cracks in rolling contact.
… various contact pressures. Detailed analysis of damage progression was carried out to study the mechanisms of fatigue failure. A boundary element analysis was used to determine the stress intensity factors around the crack front and stress distributions on the surface in the presence of the …
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Experimental Nanoengineering of Multifunctionality into an Advanced Composite Laminate
… notched tensile strength with equivalent damage progression as revealed through in situ testing using synchrotron radiation computed tomography (SRCT). The IMCs demonstrated here, with electrically and thermally conductive interlaminar regions and surfaces, support future demonstrations of …
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Damage characterization and modeling of notched graphite/epoxy sandwich panels in compression
Damage tolerant design, which focuses on a structure's ability to perform in a damaged state, is widely used in the aerospace industry today. Although extensive research has been carried out in this area for notched composite laminates, a relatively small fraction has dealt with compressive loading …
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Significance of nanosilica incorporation in type G oil well cement pastes
… penetration test (RCPT), and axial degradation/damage progression analysis and quantification after carbonic acid exposure testing. Degradation testing was performed by simulating conditions of geosequestration in a sandstone formation at a depth of roughly 1 km. These conditions were created by …
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Nonlinear System Identification of Physical Parameters for Damage Prognosis and Localization in Structures
… thus, is to develop quantitative assessment of damage accumulation from the earliest stages of the fatigue process and to provide a structure's signature that is dependent of the damage stage. One such signature is the structure's response to forced excitation. The realization of such a goal …
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Scale-model investigation of brittle tunnel failure using a true-triaxial device
… However, the factors contributing to the progression and extent of brittle failure damage remain not fully understood, limiting the predictive and preventive capabilities. This dissertation aims to improve the understanding of tunnel brittle instabilities through laboratory experiments. …
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Impact of cross section, web reinforcement and load history on the seismic performance of slender concrete walls
… load history the C-shaped walls have a similar damage progression leading to a buckling-rupture failure and a nearly identical strong-axis load-deformation response up to the peak flexural strength. However, bi-directionally loaded walls exhibit earlier onset of critical damage limit states and …
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Predicted Redidual Strength of Damaged IsoTruss® Structures
… a linear analytical approach to explore the damage tolerance or residual strength as a function of increasing damage in traditional single and hybrid-grid IsoTruss® structures. Residual strength was studied for structures subjected to axial compression, torsion and flexural bending, …
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