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Full-Text Articles in Mechanical Engineering
Ascent And Decompression Of Viscous Vesicular Magma In A Volcanic Conduit, Helene Massol, Claude Jaupart, Darrell Pepper
Ascent And Decompression Of Viscous Vesicular Magma In A Volcanic Conduit, Helene Massol, Claude Jaupart, Darrell Pepper
Mechanical Engineering Faculty Research
During eruption, lava domes and flows may become unstable and generate dangerous explosions. Fossil lava-filled eruption conduits and ancient lava flows are often characterized by complex internal variations of gas content. These observations indicate a need for accurate predictions of the distribution of gas content and bubble pressure in an eruption conduit. Bubbly magma behaves as a compressible viscous liquid involving three different pressures: those of the gas and magma phases, and that of the exterior. To solve for these three different pressures, one must account for expansion in all directions and hence for both horizontal and vertical velocity components. …
Reliability Indices For Bolted And Nailed Connections In Wood Structures, David Pollock, Donald A. Bender
Reliability Indices For Bolted And Nailed Connections In Wood Structures, David Pollock, Donald A. Bender
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
Recently published test data for bolted and nailed connections was evaluated to assess the structural reliability inherent in current allowable stress design procedures for connections in wood structures. Reliability indices were determined for timber connections using standard firstorder, second moment (FOSM) procedures. For the connections considered in this study, reliability indices range from 2.6 to5.1, generally providing higher levels of safety than the structural members in timber structures.
Application Of Dynamic System Identification To Timber Beams - Part Ii, S T. Peterson, D I. Mclean, M D. Symans, David Pollock, W F. Cofer, R N. Emerson, Kenneth J. Fridley
Application Of Dynamic System Identification To Timber Beams - Part Ii, S T. Peterson, D I. Mclean, M D. Symans, David Pollock, W F. Cofer, R N. Emerson, Kenneth J. Fridley
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
In a companion paper, a method of global nondestructive evaluation (NDE) for identifying local damage and decay in timber beams was developed and verified analytically using a finite-element model of a timber beam. The previously presented method of damage localization employs experimental modal analysis and an algorithm that monitors changes in modal strain energy between the mode shapes of a damaged beam with respect to the undamaged state of the beam. In this second part of a two-part paper, experimental laboratory tests on simply supported timber beams are presented to verify the capabilities and determine the limitations of the proposed …
Application Of Dynamic System Identification To Timber Beams - Part I, S T. Peterson, D I. Mclean, M D. Symans, David Pollock, W F. Cofer, R N. Emerson, Kenneth J. Fridley
Application Of Dynamic System Identification To Timber Beams - Part I, S T. Peterson, D I. Mclean, M D. Symans, David Pollock, W F. Cofer, R N. Emerson, Kenneth J. Fridley
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
In this first part of a two-part paper, development of a method of dynamic system identification for timber beams is presented with an analytical verification of the method using a finite-element model. A method of global nondestructive evaluation for identifying local damage and decay in timber beams is investigated in this paper. Experimental modal analysis is used in conjunction with a previously developed damage localization algorithm. The damage localization algorithm utilizes changes in modal strain energy between the mode shapes of a calibrated model, representing the undamaged state of the beam of interest, and the experimentally obtained mode shapes for …
Fatigue Assessment Of Traffic Signal Mast Arms Based On Field Test Data Under Natural Wind Gusts, Genda Chen, Jingning Wu, Jiaqing Yu, Lokeswarappa R. Dharani, Michael G. Barker
Fatigue Assessment Of Traffic Signal Mast Arms Based On Field Test Data Under Natural Wind Gusts, Genda Chen, Jingning Wu, Jiaqing Yu, Lokeswarappa R. Dharani, Michael G. Barker
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
In recent years, several states including Missouri, Wyoming, California, and Texas experienced fracture failures of traffic signal mast arms. Almost all the failures are associated with the propagation of defects or cracks. It is therefore imperative to evaluate existing mast arms using a simple yet accurate procedure. A statistical methodology is proposed to predict the fatigue life of signal mast arm structures on the basis of field-measured strain data. The annual occurrence of various stress levels is determined using the historical wind speed data in the vicinity of a mast arm structure and the strain readings of the structure under …