Innovative connection in wooden trusses Matteo Barbari a , Alberto Cavalli a , Lorenzo Fiorineschi b , Massimo Monti a , Marco Togni a,⇑ a GESAAF Department of Agricultural, Food and Forestry Systems, University of Florence, Via San Bonaventura 13, I-50145 Firenze, Italy b DIEF, Department of Industrial Engineering, University of Florence, Via Santa Marta 3, I-50139 Firenze, Italy highlights  A new connection system for traditional timber truss is proposed.  The new truss is theoretically analysed (FEA), built and tested on a test bench.  The original connection system is running as expected.  The new joint withstands forces 4 time higher than design value, without fail.  It can easily protect a large surface of the sides of the building from precipitation. article info Article history: Received 4 March 2014 Received in revised form 3 June 2014 Accepted 16 June 2014 Keywords: Timber truss Steel connection Overhanging eave Mechanical performance Finite Elements Analysis Load-carrying tests abstract An innovation of the traditional timber truss is proposed, designed, built and tested. It is an original join- ing system to connect the top-chord and the tie–beam. The joint studied enables prolonging the rafter over the linkage with the tie, so as to form overhanging eaves. The behaviour of the connection under loads was analysed either by considerations relating to the possible limit states and by means of Finite Elements Analysis (FEA). In accordance with the design which was theoretically analysed, a prototype was made and it was subjected to loading tests that gave positive results. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction The traditional wooden truss is an old structure that has been used for centuries. The oldest known example of a classical woo- den truss is in the Church of Saint Catherine’s Monastery on Mount Sinai, dating from the 6th century A.D. [1,2]; in these trusses the king-post is detached from the tie and suspended. The critical node of this system has the task of transmitting the thrust acting in upper-chord to the tie–beam by means of a heel connection. By its nature this traditional system has the following limits: the rafter cannot continue beyond the point of insertion in the tie–beam, which generally rests inside the bearing wall; further- more, the length d (Fig. 1) is often limited by the thickness of the supporting structure. Overhanging eaves are normally obtained by putting in place cantilevered bricks or stones and are therefore limited in size; in some situations, to obtain large eaves, more or less complicated additional superstructures are used. In many cases, for example in the field of agricultural service structures, the designer requires buildings with large eaves. Some of the most significant advantages are: – achieving efficient protection of buildings from rain; this is very important especially for structures that are delicate in some ways, and that by their nature have a high degree of sustainabil- ity, and are therefore suitable for implementation in areas of particular environmental sensitivity: first wooden structures, but also raw earth, straw and similar; – it contributes to building passive cooling, especially in temper- ate and tropical zones, causing appreciable energy savings; – it creates an outdoor space that is not entirely exposed to climatic elements, and therefore is very often useful in buildings that house production processes; http://dx.doi.org/10.1016/j.conbuildmat.2014.06.022 0950-0618/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +39 055 3288608; fax: +39 055 310224. E-mail addresses: matteo.barbari@unifi.it (M. Barbari), alberto.cavalli@unifi.it (A. Cavalli), lorenzo.fiorineschi@unifi.it (L. Fiorineschi), massimo.monti@unifi.it (M. Monti), marco.togni@unifi.it (M. Togni). Construction and Building Materials 66 (2014) 654–663 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat