Eksperimentalno određivanje nosivosti veza ostvarenih metalnim konekterima ŽIKICA M. TEKIĆ, Univerzitet u Beogradu, Originalni naučni rad Arhitektonski fakultet, Beograd UDC: 624.014.2.072.9 SAŠA M. ĐORĐEVIĆ, Univerzitet u Beogradu, Arhitektonski fakultet, Beograd U radu je prikazano eksperimentalno određivanje nosivosti veza ostvarenih metalnim konekterima tipa WOLF i LKVC. S obzirom na kompleksnost veza ostvarenih ovim savremenim mehaničkim spojnim sredstvima, predmet rada obuhvata samo nosivost bočne veze (naprezanje u spoju metal-drvo). Cilj sprovedenih eksperimentalnih ispitivanja je bio da se utvrdi nosivost bočne veze ostvarene metalnim konekterima, u skladu sa odredbama Evrokoda 5 i da se paralelno sa tim analizira odnos nosivosti ova dva tipa konektera, sa aspekta njihove geometrije. Eksperimentalno ispitivanje je sprovedeno na više uzoraka, opterećivanjem uzoraka do dostizanja granične nosivosti bočne veze. Diskusija rezultata ispitivanja je obuhvatila analizu pomerljivosti veza za različite nivoe opterećenja, kao i način dostizanja granične nosivosti bočne veze. U zaključku je dat komentar o utvrđenim graničnim nosivostima bočne veze, za određena pomeranja veze, i zauzet je stav po pitanju dobijenih rezultata.

The aim of this paper is to present numerical investigations of dynamic characteristics and bending stiffness for cross laminated timber floor panels with and without service openings. Five-layer panels with the outer layers oriented in the longitudinal direction of the panel have been analyzed. In order to explore the full potential of this floor system using a limited number of measurements and structural tests, models based on the finite element method have been proposed, validated against experimental results and then used to investigate the effect of opening position in the floor on main structural performance parameters. The results showed that, when the need for additional service opening appears, a slight decrease of the main structural characteristics of the cross laminated timber floor panels is achievable with an adequate geometrical position of the opening in the floor.

Original scientific paper This paper demonstrates the results of experimental determination of load-bearing capacity of structural timber member connections realized by nail metal connector plates which represent a new type of mechanical fasteners in load-bearing timber structures. The application of this type of metal connector should eliminate weakness of the standard metal connector plates produced by sheet perforating and pulling the teeth perpendicular to a sheet plane. The aim of the conducted experimental study was to determine the load-bearing capacity of connections realized by nail metal connector plates, in accordance with the provisions of Eurocode 5. Experimental testing was conducted by loading of multiple samples up to the limit bearing capacity of connection realized by nail metal connector plate. Discussion of the test results included the analysis of the limit bearing capacity of connection for different values of connection displacements, comparison of the obtained results with characteristic load-bearing capacity of standard type of metal connectors and with loadbearing capacity of nails calculated in accordance with limit state theory. Review of the determined limit bearing capacities of realized connections was given in the conclusion, together with the comment on test results, for the purpose of improving the application of metal connectors in modern systems of timber structures. Keywords: displacement; joint; limit bearing capacity; metal connector plate; nail Čavlasta metalna spojnica -eksperimentalno određivanje nosivosti nastavka drvenog štapaIzvorni znanstveni članak U radu je prikazano eksperimentalno određivanje nosivosti spojeva ostvarenih čavlastim metalnim spojnicama, koji predstavljaju novo mehaničko spojno sredstvo u drvenim konstrukcijama, čija bi primjena trebala eliminirati nedostatke koje imaju standardni tipovi metalnih spojnica, koje se proizvode perforacijom lima i izvlačenjem zubi izvan ravnine lima. Cilj provedenih eksperimentalnih ispitivanja je bio da se utvrdi nosivost spojeva ostvarenih čavlastim metalnim spojnicama, u skladu s odredbama Eurokoda 5. Eksperimentalno ispitivanje je provedeno na više uzoraka, opterećivanjem uzoraka do dostizanja granične nosivosti spoja izvedenog čavlastim metalnim spojnicama. Diskusija rezultata ispitivanja je obuhvatila analizu granične nosivosti spoja za različite vrijednosti pomicanja spoja, usporedbu dobivenih rezultata s karakterističnom nosivošću standardnih tipova metalnih spojnica i računskom nosivošću čavla po teoriji granične nosivosti. U zaključku je dan komentar o utvrđenim graničnim nosivostima ostvarenih spojeva i zauzet je stav po pitanju dobivenih rezultata, u svrhu unaprijeđenja primjene metalnih spojnica u suvremenim sustavima drvenih konstrukcija.

The paper presents wooden trusses with parallel chords designed in the System of lightweight roof girders-LKV system, and their application in the construction of buildings. The basic static systems of these girders, their characteristics, as well as numerous examples of constructed wooden structures are presented. In the structure of the wooden constructions, these girders can play the role of bearing elements for receiving gravity loading, as well as the role of lateral bracing frame.

The paper presents timber frame truss constructions in the LKV system and their application in the one hipped end gable roofs. Special attention is paid to the design of the side sector of the roof, as a function of the static height of the girder and the size of the associated load. The basic principles of functional organization of characteristic roof sectors are given, which is important for defining the geometry of all girders that form a timber structure. Unification of prefabricated elements is important for the production and economy of the timber structure. As part of the timber structure, the position and geometry of the bracings are also given, as constituent elements of the roof structure.