This article proposes a numerical investigation of the frictional heating developed in sliding bearings under high velocities and influence relevant temperature rise on mechanical characteristics device. A three-dimensional finite element model bearing is created heat generation modelled through thermal source inserted at surface bearing, with intensity dependent coefficient friction, contact pressure velocity. The friction value adjusted step-by-step velocity used to update flux resisting...

The paper illustrates an investigation on the effectiveness of dissipative bracing (DB) systems for seismic retrofit buildings with sensitive non-structural components (NSCs) and technological content (TC), such as medical centres. "Giovanni Paolo II" hospital, located in a high prone area Southern Italy , is chosen case-study. intervention hysteretic braces designed according to Italian Building Code. response hospital building investigated by means nonlinear history analyses carried out...

Fluid viscous dampers (FVDs) have shown their efficiency as energy-dissipating systems, reducing the effects induced on structures by dynamic loading conditions like earthquakes and winds. In this paper, evolution of technology is reviewed, with a focus current trends in development from passive to semi-active adaptive systems an emphasis advances adaptability control efficacy. The paper examines implementation FVDs such electrorheological, magnetorheological, variable stiffness, damping...

Crosslinked vitamin-E-stabilized polyethylene acetabular cups were compared with both commercially available conventional and custom-crosslinked in terms of wear behavior, a hip joint simulator for five millions cycles, using bovine calf serum as lubricant. We correlated the experiments results chemical characterization investigated materials: Fourier transformed infrared (FTIR) spectroscopic analyses, differential scanning calorimetry, crosslink density measurements used to assess...

This study introduces a new energy dissipation device with high damping capacity for the seismic protection of buildings. The exploits friction losses between movable shaft and lead core to dissipate takes advantage prestressing material control force. Numerical analyses are introduced evaluate influence on axial force device. Cyclic tests performed prototype demonstrate capability, an equivalent ratio ξeff approximately 55%, robust stable response over repeated cycles low sensitivity...

The paper presents the experimental characterization, formulation of a numerical model, and evaluation, by means non-linear analyses, new friction damper conceived for seismic upgrade existing building frames. dissipates energy through force triggered between steel shaft lead core prestressed within rigid chamber. is adjusted controlling prestress core, allowing achievement high forces with small dimensions, reducing architectural invasiveness device. has no mechanical parts subjected to...

The re-centring capability is recognized as a fundamental function of the isolation system, because it intended to prevent substantial permanent deformation at end earthquake that may affect serviceability structure and eventually limit isolators withstand aftershocks future earthquakes. In this study, behaviour systems composed sliding bearings with curved surfaces investigated in shake-table tests carried out on one-storey steel frame rectangular plan, scaled one third-length scale...

Supplementary energy dissipation has proved to be an effective way of protecting structures from the disastrous effects earthquakes and been used in last decades both new existing constructions. In this regard, various procedures for design damping system seismic retrofit buildings have formulated over years, mainly focused on reinforced concrete (RC) constructions, which represent largest part stock many seismic-prone countries. The study deals with assessment a displacement-based procedure...

In common practice a perfect fit of the prosthetic framework with implant abutments is almost impossible to achieve. The mismatch, which principally induced by technological process adopted manufacture fixed prostheses, strains thus generating constraint reactions. These are static forces that load components and bone at implant-bone interface may cause remodelling. Depending on magnitude such forces, i.e. depending remodelling lead loosening screws hence failure. present study shows an in...

There is no consensus about the anatomical structure of human dura mater.In particular, orientation collagen fibers, which are responsible for biomechanical behavior, still controversial. The aim this work was to evaluate mechanical properties and microstructure lumbar mater. We performed experimental characterization in longitudinal circumferential directions a scanning electron microscopy observation tissue. Specimens mater were removed from dorsal-lumbar region (T12-L4/L5) six subjects at...

Friction plots of polymers sliding on smooth metal surfaces are generally characterized by two regions distinct dependency the normal load, with low sensitivity at stress levels followed a sharp change in rate decrease friction increasing pressure above plastic flow limit polymer. A simplified model is proposed to describe this behavior which accounts for effect load growth real contact area and shear interface between polymer mating surface. The has wide generality when expressed terms...

The identification of nonlinear structural dynamic systems is a common task in civil engineering, where it applied for damage detection and health monitoring. In this paper, procedure based on the extended Kalman filtering (EKF) proposed online estimation coefficient friction friction-based isolators, such as Friction Pendulum Systems or Curved Slider Surface Sliders, starting from measured accelerations isolated superstructure. suitability EKF estimator application demonstrated two case...

Abstract A huge amount of rubber waste coming from tire industry or other sources (eg, weather strips producers) has attracted interest researchers to investigate the possibility recycling used for various products, particularly in construction sector. This article presents a series experimental and numerical investigations evaluate feasibility regenerated synthetic ethylene propylene diene monomer (EPDM) production building seismic isolation system. Four blends using two different EPDM are...