Description of the TRJ node The TRJ - Top Roof Joint - is made up of four...
Description of the TeRJ node
The TeRJ - Tensile Roof Joint - is made up of two articulated elements - a rigid arm A and a tilting element B - screwed to the ground beams and connected by a bolt C. This element limits the movement of the knot in the YZ plane. a horizontal pushed connection eliminated.
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.
Tensioned joint with constrained traction in correspondence with the holes for connection to the roof truss beams (profile TRN 170/3). The hypothesized constraint allows the rotations in the XZ plane and does not allow displacements in the X direction (horizontal push eliminated) and Z. The calculation stress is applied on the whole section of the bolt / tie rod and generates a tractive effort.
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 a force (F) for four distinct inclinations, arbitrarily chosen; the angle of rotation of the joint is α = 15 °, 30 ° 45 ° and 60 °. The tractive force (F) assumes the following 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.