Experimental analysis on friction materials for supplemental damping devices

Abstract

In this paper, the friction coefficient and the cyclic response of different interfaces for friction devices are investigated by means of experimental tests under displacement control. In particular, six interfaces have been tested: steel–steel, brass–steel, sprayed aluminum–steel and three different rubber based friction materials adopted, respectively, in automotive applications, electrical machines and applications requiring low wearing.\ud Static and kinetic friction coefficients have been evaluated and the influence of the interface pressure has been analyzed. The variation of the sliding force during the cyclic loading history has been investigated by comparing also the response coming from the use of different washers: circular flat washers and cone shaped annular disc springs.\ud The work is aimed at the investigation of friction materials to be applied within the connecting elements of beam-to-column joints according to the double split tee configuration with friction pads

Finite Element Analyses on Free From Damage Seismic Resisting Beam-to-Column Joints

“…This project aims at developing and seismically prequalifies novel types of steel joints that dissipate the seismic energy by means of friction at the level of surfaces in contact clamped by preloaded bolts and specifically designed to undergo relative sliding at a given force level. The cyclic behaviour of these joints is stable with low degradation, even though it depends on the friction material used at the sliding interface [36][37][38][39][40]. Figure 1 depicts the two main typologies of the joints tested within [41].…”

Experimental Analysis on the Cyclic Response of Beam to Column Joints: State-of-the-Art at Salerno University

“…k wc , can be assumed equal to 1, provided that normal stress at the column root radius does not exceed 70% of steel ultimate stress,. Thus the column web panel in transverse compression resistance is: (20) Therefore, the over-strength level of the panel web in transverse compression is given by the ratio: (21) which is consider sufficient in order to prevent brittle failure modes.…”

“…To this scope, aiming to perform a further step towards the codification of design rules for dissipative joints, in last five years a significant experimental and analytical activity has been devoted to this topic by the research group of the University of Salerno [16][17][18][19][20][21]. In particular, to date, the experimental activity performed has regarded classical and innovative joint solutions which, according to the basic principle proposed by the research group of dissipating the seis-mic energy always in a specific joint component (i.e.…”

Eccentrically Braced Frames Designed for the Energy Dissipation Optimization

“…In addition, external plates have slotted holes also in vertical direction to allow vertical displacement due to vertical loads (Figure 4). Adopted bolts are high resistance class 8.8 while the friction material adopted (FREEDAM project) is sprayed aluminum that is able to exhibit a friction coefficient of about 0.5 [38]- [39]. …”