Global ETD Search
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 62 for “"Critical Load"”.
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Dynamics of power systems at critical load levels
… from a dynamic viewpoint in the context of critical modes of the linearized system matrix. The eigenvalue algorithms have been used to establish a correspondence between the critical modes and certain system states. Two case studies have been performed to analyze the dynamic nature of the …
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Static and dynamic stability analysis of a truss model
… truss model· is subjected, separately, to static loads, dynamic step loads, and dynamic impulse loads. For each loading, the results are presented in the form of stability boundaries and displacement criteria. For the static loading, the stable equilibrium displacement fields are determined by …
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Stability analysis of the Church of the Nazarene Varax dome
… Church of the Nazarene Varax dome under various load distributions. A model of the dome constructed using I-DEAS is presented and results of linear and nonlinear analyses are discussed. A comparison between the critical load obtained using nonlinear analysis and combined linear and nonlinear …
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Combined linear/nonlinear stability analysis of plane and space frames
… effectiveness of the combined analysis for the critical load predictions. Several test problems and a glulam dome cap are analyzed, and the critical load prediction curves and the nonlinear equilibrium paths are presented. It is verified that the B33 finite element in ABAQUS is capable of …
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A critical assessment of crack growth criteria in unidirectional composites
… subjected to uniform in-plane remote loading. The purpose of this study is to gain a better understanding of several theoretical models for predicting the direction of crack propagation and the level of load causing crack extension, and to present a new model for predicting the …
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New Truck Loading Model For Rural Bridges In Saskatchewan
… lack of existing information on estimating the critical load effects occurring on short span bridges, on low traffic roadways, and over specific reference periods makes it difficult to perform the bridge evaluations with an adequate degree of confidence. This study focuses on aspects of the …
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Experimental Strength Characterization of Epoxy Double Lap Joint for Carbon-Fiber Reinforced Polymer Tube
… joints. This report focuses on predicting the critical load of an epoxy adhesive double lap joint through experimentation. Test samples were designed and fabricated from off-the-shelf spindle-wound tubes and machined forged carbon fiber. An assembly of aluminum parts was designed and fabricated …
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Nanoindentation Techniques for the Evaluation of Silicon Nitride Thin Films
… of the properties of these films under diverse loading and failure conditions is a necessary prerequisite to their use in biomedical devices. Three wafers of silicon nitride-coated silicon were obtained from Lawrence Livermore National Laboratory and used to create 96 samples. Samples were …
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Nonlinear Stability Analysis of Frame-Type Structures with Random Geometric Imperfections Using a Total-Lagrangian Finite Element Formulation
… imperfections will become unstable at a load less than a specified fraction of the perfect critical load. The overall objective of this dissertation is to present such a method for frame-type structures that become unstable at limit points. The overall objective may be broken into three …
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Cyber-physical systems of microgrids and control strategies for enhancing electrical grid resilience
… group of distribution, generation, storage, and loads. The concept has emerged to utilize renewable energy and increase resiliency of power systems. Modern microgrids rely on sophisticated communication and controls, which require them to interact with cyber-physical systems. In addition, this …
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Análise dinâmica de placas sandwich comprimidas simplesmente apoiadas
… rectangular plates under a compressive uniform load acting in the middle plane. The dynamical instability was also analyzed. The equations of motion were obtained through a variational approach. The changes in the natural frequencies and stability loads were analyzed according to the variations …
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Vibrações de placas sandwich enrijecidas por barras conectoras
… in the core, under compressive uniforme load acting in the midplane, as well as the determination of the critical loads by a dynamical process. The equations of vibration were obtained through the substitution of the constitutive equations into the equations of motion. Some results, as …
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Finite-element modeling of a composite bridge deck
… resin. The bridge deck is subjected to a patch load at the center and the finite-element results obtained in the form of deflections, strains, and equivalent flexural rigidity are compared with experimental results. A good correlation is found to exist between the finite-element results and the …
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Simulation of microgrid system and low-cost wireless communication network
… a converter-fed battery storage system and a critical load which must be fed power under all circumstances. The microgrid is capable of functioning in either grid-connected or isolated modes of operation. A passive islanding detection method is utilized to switch over from P-Q to V/F control …
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An incremental, non-linear displacement method for the elastic analysis of space trusses and plane frames
… analysis of space trusses. In the incremental loading procedure the elastic critical load of a structure is determined by establishing the load at which the determinant of the stiffness matrix passes through zero. Chord shortening due to bowing of truss compression members which have an initial …
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Optimization Methods for Distribution Systems: Market Design and Resiliency Enhancement
… and to increase participation of responsive loads (RL) and non-conventional generation resources. On the resiliency side, plug-in hybrid electric vehicles (PHEV), energy storage systems (ESS), microgrids (MG), and distributed energy resources (DER), can be leveraged to restore critical load …
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Characterization of mirco/nano mechanical and tribological properties of polymeric coatings deposited on steel
… test results showed that the highest average critical load, at which the adhesion to the substrate steel failed, was 100.03 mN for the 2K coating, thus indicating that the 2K coating had the greater adhesion strength.</p>
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Estabilidade local de painéis cilíndricos enrijecidos
Results from primary and secondary bifurcation loads and also results from a non-linear analysis of elastic local stability of stringer stiffened cylindrical shells under axial compression are presented. The effects due to stiffeners spacing and slenderness as well as modal interaction and inicial …
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High Fidelity and Efficient Computations of Dynamic Loads for Multidisciplinary Design Optimization of Flexible Transport Aircraft
… of airframes is tightly wounded to its loads analyses as the process is usually conducted employing a deterministic set of critical load cases. The sheer number of scenarios required to estimate the critical loading conditions prevent these two processes from integrating. In this thesis, …
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Online Voltage Stability Monitoring and Control Using Limited Synchrophasor Measurements
… environment. This research addresses the critical issues by proposing three different methods. Voltage Stability Assessment Index (VSAI) is a Thévenin Equivalent (TE) based method considering voltage dynamic mechanisms. To extend the model from one load bus to a critical load center, …
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