Search results for "REINFORCED"

Influence of column shear failure on pushover based assessment of masonry infilled reinforced concrete framed structures: A case study

2017

Structural frames, constructed either of steel or reinforced concrete (RC), are often infilled with masonry panels. However, during the analysis of the structural frames, it has become common practice to disregard the existence of infills because of the complexity in modeling. This omission should not be allowed because the two contributions (of infills and of frames) complement each other in providing a so different structural system. The use of different modeling assumptions significantly affects the capacity as well as the inelastic demand and safety assessment. In specific, the adoption of equivalent diagonal pin-jointed struts leaves open the problem of the evaluation of the additional…

Analysis of a Collapsed Long-Span Reinforced Concrete Roof in South Italy: Design Mistakes and Material Degradation

2020

In 2004, during ordinary maintenance work, consisting of waterproofing a building located in the south of Italy, the long-span (14.5 m) in situ RC roof partially collapsed. The building, constructed in 1950, was in service as a cinema until 1967 and then utilized as a school until 1985. Lastly, it was a hotel until 2000. In 2004, when the building was not in service and was undergoing maintenance work, it partially collapsed under dead load. After the collapse, which involved a large portion of the roof, several beams, and two columns, the Italian court nominated an official technical consultant to investigate the direct and related causes of the failure. After the main causes were identifi…

Prediction Equations for Out-of-Plane Capacity of Unreinforced Masonry Infill Walls Based on a Macroelement Model Parametric Analysis

2021

In the seismic performance assessment of reinforced concrete (RC) frames, a reliable estimation of the capacity of unreinforced masonry (URM) infill walls is of utmost importance to ensure structural safety conditions. With particular attention to the out- of-plane (OoP) capacity of URM infill walls after in-plane (IP) damage, the issue of defining reliable analytical prediction models for the assessment of the capacity is an ongoing study. In this paper, empirical equations are proposed for the evaluation of the infilled frame’s OoP capacity, with or without IP damage, based on an extensive numerical parametric analysis, focusing on the influence of the key parameters that govern the mecha…

Comparative evaluation between glass and polyethylene fiber reinforced composites: A review of the current literature

2017

Background Fiber reinforced composite (FRC) is a promising class of material that gives clinicians alternative treatment options. There are many FRC products available in the market based on either glass or polyethylene fiber type. The aim of this study was to present a comparison between glass and polyethylene fiber reinforced composites based on available literature review. Material and methods A thorough literature search, with no limitation, was done up to June 2017. The range of relevant publications was surveyed using PubMed and Google Scholar. From the search results, articles related to our search terms were only considered. An assessment of these articles was done by two individual…

A semi-empirical stress-strain model for equivalent strut fiber-section modeling of infilled frames

2017

Infill-frame interaction is commonly modeled by means of equivalent strut macro-models. The main difficulty in using this phenomenological approach is to properly calibrate a force-displacement curve for the struts, as this depends not only on the geometrical and mechanical properties, but more specifically on the different potential damage mechanisms which may occur for the infill-frame system subject to lateral forces. If fiber-section elements are used as diagonal struts, the force-displacement curve is substituted by a stress-strain law. In both cases, the attribution of the inelastic law of the struts, based on a mechanical approaches, is not valid in general, as mechanical approaches …

EVALUATION OF FRAGILITY OF INFILLED FRAME STRUCTURES SUBJECT AFTERSHOCKS BY MEANS OF DOUBLE INCREMENTAL DYNAMIC ANALYSIS APPROACH

2018

The paper investigates the role of masonry infill walls on the seismic fragility of reinforced concrete structures subject to mainshock/aftershock sequences. An assessment framework aimed at determining aftershock fragility curves of bare frames and infilled frames is presented. The framework is based on a Double Incremental Dynamic Analysis (D-IDA) approach, which provides the adoption of ground motions defined by combining a fixed intensity mainshock with a set of variable intensity aftershocks. Mainshock (MS) intensity is scaled several times and combined with the same set of aftershocks (AS). Chord-rotation and shear limit states are specifically defined to consider the influence of mas…

Il recupero parziale di opere in muratura di interesse storico in zona sismica

2011

Design av en offshore gangbru i fiberarmert polymer

2018

Masteroppgave bygg BYG508 - Universitetet i Agder 2018 Innovation and development are essential for a market in demand of faster, lighter and stronger solutions. As a material with high strength to weight ratio, and good possibilities of being premade, fiber reinforced polymers can meet those requirements. However, it has yet to challenge concrete, steel and aluminum as a structural material. This is the underlying challenge for the problem statement of this assignment, to construct an offshore gangway using fiber reinforced polymers. The design concept is based on existing steel and aluminum constructions within the size range of 25- 30m fully extended. To solve the problem and answer the …

Infrared Thermography assisted evaluation of static and fatigue Mode II fracture toughness in FRP composites

2019

Abstract The work proposes the combined use of a Modified Transverse Crack Tension (MTCT) test coupon and Infrared Thermography, to evaluate the static and fatigue behaviour of Fibre Reinforced Polymer composites under Mode II delamination. Artificial delaminations starters are added to the TCT coupon, whose effects on the Strain Energy Release Rate are discussed. Infrared Thermography and Thermoelastic Stress Analysis are implemented to investigate stresses and delaminations growths on two FRP materials: a pre-preg IM7/8552 carbon fibre-epoxy and a glass-fibre reinforced epoxy laminates. The thermographic, thermoelastic and second harmonic signals have been obtained and used to monitor the…

Thermoelastic Stress Analysis of modified Transverse Cut Tensile composite specimens under pure Mode II fatigue delamination

2018

The present work investigates the behaviour of a Transvers Crack Tensile (TCT) specimen undergoing fatigue loading, by means of a Thermoelastic Stress Analysis (TSA) experimental setup. The TCT is a tensile composite specimen where a number of internal layers are cut through the beam width. The presence of such transverse notch favours the formation of interlaminar Mode II delaminations, starting from the notch tips and propagating between the cut and continuous plies. In this work, a modification is adopted to the classic TCT specimen, where insert films, mimicking artificial delaminations, are laid across the notch tips. This is done with the purpose to favour a pure Mode II and a symmetr…