Analysis and design of a telecommunication steel tower strengthened with FRP plates

VLACHAKIS, KONSTANTINOS

dc.contributor.author	VLACHAKIS, KONSTANTINOS	en
dc.date.accessioned	2019-03-27T10:43:04Z
dc.date.available	2019-03-27T10:43:04Z
dc.date.issued	2019-03-27
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/48516
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.9337
dc.rights	Default License
dc.subject	Ινοπλισμένα Πολυμερή	el
dc.subject	Ιστός τηλεπικοινωνιών	el
dc.subject	Ενίσχυση	el
dc.subject	Πειραματικές δοκιμές	el
dc.subject	Εναλλακτική μέθοδος	el
dc.subject	Carbon Fiber Reinforced Polymer	en
dc.subject	telecommunication tower	el
dc.subject	Alternative method	el
dc.subject	Experimental testing	el
dc.subject	Stregthening	el
dc.title	Analysis and design of a telecommunication steel tower strengthened with FRP plates	en
dc.contributor.department	ΔΠΜΣ Δομοστατικός Σχεδιασμός και Ανάλυση Κατασκευών	el
heal.type	masterThesis
heal.classification	CIVIL ENGINEERING	en
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2018-10-25
heal.abstract	Telecommunication lattice towers are probable the most common type of tower used for telecommunication purposes. They have many advantages like the easy on-site transport and erection due to the use of angle sections. However, over the last years several towers’ failures have occurred due to severe weather conditions. Also, telecommunication market needs have a tremendous increase, more and larger antennas need to be placed on existing towers. Based on the above it seems that in many cases strengthening of existing towers is unavoidable. In the current practice, replacing the leg member with a larger angle is not feasible, so a second angle is usually inserted and connected with the existing section to form a built-up member in a star-battened configuration. This common strengthening method has some significant disadvantages, with most important the increasement of the structural weight and the area swept by the wind, and therefore the wind forces. An alternative strengthening method is introduced in this thesis, by which the legs or braces are strengthened using Carbon Fiber Polymer plates (CFRP). Because both literature and experimental tests on steel sections strengthened with CFRP plates are limited, it is needed to be executed several experimental tests on steel sections strengthened with CFRP plates. For this purpose, three tests are executed on such specimens, one tensile test and two four-point bending tests, in order to estimate the response and the strength of strengthened steel members. Besides the tests, analytical calculations based on two different methods and numerical analyses using Finite elements software are made. As it is concluded, CFRP strengthening increased tensile and bending capacity of the steel plate almost 5 times, independently if the CFRP was in the tension or in compression side. That means that CFRP plates have also a large strength on compression stresses. Using the results of the experimental tests, the design of a telecommunication tower strengthened with CFRP plates follows. At first, an evaluation of a typical existing tower is made. As it is proved the existing tower cannot bear some typical loads in order to fulfil codes’ requirements and future telecommunication needs. Both towers’ legs and braces are overloaded almost all over the height of the tower. In the alternative strengthening method CFRP plates are bonded only to members that fail. This application doesn’t increase the wind loads since the reference wind area is the same and also there is no increase in dead loads. Nonlinear analysis and then structural design is executed. As it is concluded, finally, the strengthening of an existing telecommunication tower using CFRP plates is a possible solution, that may be very effective and has certain advantages comparing with the conventional strengthening method. It is obvious, that more research need to be done so that this alternative method can be feasible. (en)	el
heal.advisorName	Vayas, Ioannis	en
heal.committeeMemberName	Vamvatsikos, Dimitrios	en
heal.committeeMemberName	Thanopoulos, Pavlos	el
heal.academicPublisher	Σχολή Πολιτικών Μηχανικών	el
heal.academicPublisherID	ntua
heal.numberOfPages	69
heal.fullTextAvailability	true