long term test; loss of preload; Friction connection
Abstract :
[en] In the framework of a RFCS project entitled “FREEDAM -Free From Damage Connections”,
innovative friction connections activated as dissipative zones in case of seismic actions are studied,
with the objective to avoid any damage in the structures not only for frequent and occasional
seismic events, but also for destructive earthquakes. These friction connections are made of
stainless steel plates with specific coatings fastened with preloaded bolts placed in long slotted
holes allowing significant displacement of the plates when the friction resistance is reached and so
allowing significant dissipation of energy.
As a partner of this project, The University of Liege is in charge of proposing analytical design
procedures for these innovative joints and in particular of investigating the evolution of the
prestressing in the bolts according to time, a key parameter when it is intended to dissipate energy
through the activation of friction.
This paper presents first preliminary results obtained through long term tests (5 months) performed
on steel plates with particular coatings fastened with M20 Bolts. The main parameters registered
during these tests were the relative displacements between the connected plates and the evolution of
the prestressing in the bolts. The tests were performed according to EN 1090-2, in order to assess
the loss of preloading over time and the creep of the plate. The final objective of the conducted
studies is to propose a methodology to predict the prestressing loss in order to ensure that a
minimum level of prestressing is kept over the full life of the structures, i.e. at least 50 years.
Disciplines :
Civil engineering
Author, co-author :
D'Antimo, Marina ; Université de Liège - ULiège > Département ArGEnCo > HECE (Hydraulics in Environnemental and Civil Engineering)
