Download or read book Nonlinear Finite Element Modeling and Characterization of Guyed Towers Under Severe Loading written by Haijian Shi and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Guyed towers have been widely employed in the telecommunication industry. This study thus intends to improve the understanding and analysis of guyed towers that undergoes not only large deformation, but also large strain. Impulsive loads are potential threat to the safety of guyed towers besides wind load, earthquake, and ice storm. This research explores the area using an already developed P-I diagram method and nonlinear finite element modeling to provide an efficient and effective way for structural integrity evaluation for guyed towers. The mechanical characteristics of basic components of guyed towers are investigated first. Because guyed towers with large defection also have large strain in some parts, material nonlinearity is introduced by improving the existing FEM codes for trusses and cables. It is found that the improved methodology can well predict the performance of structures and tremendous difference exists between elastic analysis and inelastic analysis. Under seismic loading condition, inelasticity in material can help dissipate the inputted seismic energy and reduce the intensity of structural response. To evaluate the guyed tower's safety under impulsive loads, relative P-I formulas have been derived based on existing transverse velocity profiles of rigid plastic beams under impulsive loads. The impact of boundary condition and load types on the response is investigated. It is found under certain conditions only one failure mode is possible. But shear failure and bending failure can coexist under very severe impulsive loads. Most guyed towers are expected to survive light or medium impulsive loads due to their high redundancy and small loading area.
Download or read book Development of Meteorological Towers Using Advanced Composite Materials written by Sami Alshurafa and published by . This book was released on 2012 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research program involved both numerical and experimental work. The numerical analysis was conducted to simulate the static and dynamic behaviour of the 81 m meteorological FRP guyed tower under wind and ice loading. The FRP tower consisted of 16 segments each made of 3 cells connected together to form an equilateral triangle having equal sides of 450 mm. The segments were interconnected using internal sleeves. Various non-linear finite element models were developed to study a number of design parameters for the 81 m FRP tower such as, different laminates containing a variety of stacking sequences of laminate orientations with various thicknesses, different cable diameters, and appropriate guy cable spacing levels. The effect of pre-stressing the guy cables up to 10% of their breaking strength was investigated. The effect of fibre volume fraction on the design of the FRP tower was also examined. Furthermore, an 8.6 m FRP tower segment was designed using the finite element analysis and subject to the same loading conditions experienced by the bottom section of the 81 m FRP tower. A modal analysis was carried out for both the 8.6 m FRP tower segment with and without a mass on the top as well as for the 81 m FRP guyed tower to evaluate the vibration performance of these towers. The experimental work involved extensive material testing to define the material properties for use in the analysis of the 81 m FRP tower. It also involved the design and fabrication of a special collapsible mandrel for fabricating the FRP cells for the 8.6 m tower segment. The 8.6 m tower was tested horizontally under static lateral loading to 80% of its estimated failure load using a "whiffle tree" arrangement, in order to simulate a uniformly distributed wind loading. Later, the same FRP tower was erected in a vertical position and was tested with and without a mass on top under dynamic loading to obtain the natural frequencies. Lastly, a comparative study was conducted between two 81 m FRP towers having different fibre volume fractions and a steel tower having a circular cross section.
Download or read book Dynamic Response of Lattice Towers and Guyed Masts written by Murty K.S. Madugula and published by ASCE Publications. This book was released on 2001-01-01 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prepared by the Task Committee on the Dynamic Response of Lattice Towers of the Technical Committee on Special Structures and the Technical Administrative Committee on Metals of the Structural Engineering Institute of ASCE. This report is a compilation and clarification of current methodologies for the dynamic response of communication towers in a single source. The information regarding the dynamic response of lattice towers is currently scattered throughout the literature, making it difficult for the practicing engineer to obtain the information necessary for design purposes. Both self-supporting lattice towers and guyed lattice masts (guyed lattice towers) are included. Topics include: Ødynamics of cables and towers, Ødynamic analysis, Øwind loads and response, Øseismic input and response, and Øvibration control.
Download or read book Finite Element Analysis of Wood Shoring Towers Used in Urban Search and Rescue written by Robert Stevenson Blair and published by . This book was released on 2012 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the finite element modeling and analysis of wood shoring towers used by Urban Search and Rescue (US & R) teams during emergency response situations. These shores are constructed on site to provide temporary stabilization to a damaged structure. A high demand exists for experimental testing of the performance of these shores under non-ideal loading conditions, and for possible design modifications that could improve their overall behavior. To respond to this need, a total of thirteen vertical shores of the type laced post (LP) and plywood laced post (PLP) were constructed and tested at the Ferguson Structural Engineering Laboratory (FSEL) in Austin, Texas. The tests conducted on these shores aimed to investigate their performance under purely vertical load as well as various combinations of vertical and lateral loads. Finite element models for eight of the shores tested at FSEL were built and analyzed in Abaqus to compare the computed results with the actual linear elastic response of the shores. Material properties for the posts in each shore were obtained through further material testing at the conclusion of each shore test. Shore members were assumed to be isotropic. Solid elements were used to model each member, and Cartesian connector elements with a predefined nonlinear stiffness were used to model each nail. In general, the vertical load-displacement response computed from Abaqus exhibited good agreement with the laboratory results for the linear elastic range. The same general modeling scheme was then used to make design changes to the original shores based on observations gained during testing as well as modeling. Each design change was modeled, analyzed, and then compared with the computed results from the original shore design as well as the other design changes. The basis for evaluating the effectiveness of a given shore design involved comparing the bending moment diagrams for each post and the maximum first story nail slips (connector displacements). Recommendations were made for improved shore designs to be verified by experimental testing.
Download or read book Static and Dynamic Analysis of Guyed Towers written by Nabil Ben Kahla and published by . This book was released on 1993 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Tall Guyed Towers written by Michael Louis Chiesa and published by . This book was released on 1977 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Civil Engineering written by and published by . This book was released on 2006 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Special Topics in Structural Dynamics Volume 6 written by Randall Allemang and published by Springer. This book was released on 2015-04-20 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: Special Topics in Structural Dynamics, Volume 6: Proceedings of the 33rd IMAC, A Conference and Exposition on Structural Dynamics, 2015, the sixth volume of ten from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Structural Dynamics, including papers on: Aircraft/Aerospace Active Control Analytical Methods System Identification Sensors and Instrumentation
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1982 with total page 1282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalog of National Bureau of Standards Publications 1966 1976 written by United States. National Bureau of Standards. Technical Information and Publications Division and published by . This book was released on 1978 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Discrete Field Analysis of Trussed Guyed Towers written by Raja Raymond Amine Issa and published by . This book was released on 1981 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three dimensional Non linear Analysis of Guyed Towers microform written by Mohan Selvappalam and published by National Library of Canada. This book was released on 1987 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalog of National Bureau of Standards Publications 1966 1976 written by United States. National Bureau of Standards and published by . This book was released on 1978 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Finite Element Analysis of Reinforced Concrete Structures Subjected to Blast Loading written by Fouad Bakheet Aboud Beshara and published by . This book was released on 1991 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the International Offshore Mechanics and Arctic Engineering Symposium written by and published by . This book was released on 1986 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Shock and Vibration Digest written by and published by . This book was released on 1989 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
