Description of the TRJ node
The TRJ - Top Roof Joint - is made up of four articulated elements, two connections to the beams / struts A; two square section profiles B; two plates that make the node C integral and the element D that connects the node to the ridge beam. This element allows the concatenation of the ridge beams of a three-pitch roof.
TeRJ is made in the workshop in compliance with the UNI standards relating to the chemical composition of steels and welding processes (UNI EN ISO 4016: 2002, UNI 5592: 1968, UNI EN ISO 898-1: 2001, UNI EN 20898-2: 1994). The screws and bolts are made of high-strength steel class 8.8 and the rest of the elements are made of S355 steel. To guarantee greater durability, all the elements are subjected to a hot-dip galvanizing process.
Joint stressed with constrained compression in correspondence with the holes connecting the roof ridge beam (profile TRN 170/3). The hypothesized constraint allows the rotations of the ground beams. The calculation stress is applied to the whole section of the two bolts and generates a compression stress in the joint.
The results were obtained with a non-linear analysis of the stress / strain state and of the displacement / deformation behavior performed with a finite element calculation program for incremental load values. The characteristics of the materials are as follows: S355 steel plates; high strength screws and bolts 8.8. The results of the tests carried out refer to the action of two forces (F1 / F2) for four distinct inclinations, arbitrarily chosen; the angle of rotation of the joint is α = 15 °, 30 °, 45 ° and 60 °. Compression forces (F1 / F2) reach the following stress values:
Where: Se = Max stress at the elastic limit.
Ss = Max stress at the complete plasticization of the resistant section.
Results of the force F expressed in Newton (N) equal to 10 N = 1 Kg.
This type of knot is applied by Futhura in the construction of earthquake-proof houses.
Questo tipo di nodo viene applicato da Futhura nella costruzione di case antisismiche.