Comportamento experimental de diferentes tipos de conectores metálicos

A realização de estruturas mistas de aço e betão requer o funcionamento conjunto destes dois materiais. A ligação entre eles é conseguida com a utilização de conectores metálicos. Neste âmbito, tem sido realizada uma considerável quantidade de estudos que abordam o comportamento de diversos tipos de conectores metálicos. O desejo de obter um comportamento óptimo com custos mínimos motivou o desenvolvimento de várias soluções. Neste artigo, procura-se descrever o comportamento de diferentes tipos de conectores observado em ensaios experimentais realizados na Universidade do Minho (UM) ou em estreita colaboração da UM com outras entidades. Apresentam-se as vantagens e as desvantagens associadas a cada tipologia de conexão analisada. Para além dos usuais conectores tipo perno, discutem-se os resultados obtidos com conectores do tipo T, tipo Perfobond, tipo Crestbond e ligação por aderência

Fábrica do Paleão: structural assessment of iron in Portugal’s industrial heritage

Fábrica do Paleão was erected as a flagship textile factory in Portugal between 1888 and 1891. The factory was constructed with a saw-tooth roof supported by iron trusses allowing light open spaces to accommodate heavy machinery and promote industrial activity. With an aim of preserving this exemplary representative of industrial heritage in Portugal, the work seeks to establish the buildings’ historical significance and assess their structural adequacy for present and future use. After performing a global historical survey and visual inspection, the study focused on the main industrial spaces. An in depth visual inspection provided key geometric and material parameters as well as a damage assessment. Damage mapping revealed the effects of moisture throughout the structure which is caused by the lack of maintenance in recent years. To assess the impact of the damages and obtain key parameters for a further structural and safety analysis, in situ tests were performed on the cast iron columns. Columns were tested for hardness and comparison to known values indicate that they align with ordinary to high strength cast iron. A representative single frame was modelled for each of the two main rooms and a safety analysis was performed to assess the structure´s safety.info:eu-repo/semantics/publishedVersio

Análise experimental e numérica da conexão aço-betão leve realizada com pernos de cabeça

O presente trabalho procura abordar a modelação numérica da conexão entre o perfil metálico e a laje de betão, quando se utilizam conectores do tipo perno e betão leve. Utilizam se elementos finitos de volume para definir todos os elementos presentes na ligação, recorrendo ao software ATENA 3D. A partir dos modelos desenvolvidos procura-se avaliar quais os parâmetros relevantes para o comportamento da conexão aço betão leve. Recorre-se a resultados de ensaios de tipo push out anteriormente realizados na Universidade do Minho para validar os modelos numéricos desenvolvidos

Development of innovative hybrid sandwich panel slabs: Advanced numerical simulations and parametric studies

The authors honestly appreciate the collaboration of the following institutions: Civitest for developing DHCC materials and PIEP for conducting VARTM process.An innovative hybrid sandwich slab for the rehabilitation of floors in old masonry buildings was conceived, designed, and tested. This structural system is a lightweight composite floor consisting of bottom skin and shear ribs in Glass Fiber Reinforced Polymer (GFRP), a top layer of Deflection Hardening Cement Composites (DHCC), and Polyurethane foam core. In the first part of this study, the material/structural performance of the panel’s concept was assessed by experimental tests. The second part is now dedicated to the execution of advanced numerical simulations, including parametric studies, for assisting on the optimization of this composite slab system and investigating the influence of the relevant characteristics of GFRP and DHCC components. The influence of considering isotropic or orthotropic behavior for the GFRP components and linear or nonlinear behavior for the DHCC are also investigated numerically in terms of accomplishing serviceability and ultimate limit state requisites for this structural system. The parametric studies show that the thickness of GFRP rib is the most important parameter to increase the load carrying capacity of this type of slabs. Based on the results of these parametric studies, two slabs are built and tested experimentally, and the obtained results are not only used to demonstrate the effectiveness of the developed structural system, but also to appraise the predictive performance of the constitutive models adopted in the FEM-based simulations.The study presented in this paper is a part of the research project “RehabGFRP - Rehabilitation of Building Floors with Lightweight High Performance GFRP Sandwich Panels”, with reference number of PTDC/ECM/113041/2009. Furthermore, the authors honestly appreciate the collaboration of the following institutions: Civitest for developing DHCC materials and PIEP for conducting VARTM process

Estudo experimental e numérico sobre o comportamento de vigas mistas com conector Crestbond

Nesta comunicação apresenta-se um estudo sobre vigas mistas em aço e betão onde se utilizam conectores do tipo Crestbond contínuos para estabelecer a ligação entre a viga metálica e a laje de betão e garantir o funcionamento misto entre estes dois elementos. Apresentam-se os resultados de ensaios numéricos e experimentais obtidos em vigas mistas de aço e betão realizadas com conectores Crestbond, na Universidade do Minho. Os provetes consistem numa viga metálica IPE200 com um conector CR40 R10 contínuo, posicionado sobre o banzo superior da viga e soldado em todo o seu desenvolvimento, e uma laje betão armado com secção transversal de 0.40×0.10 m2. Os provetes apresentam um vão de 3.0 m e um comprimento total de 3.2 m. O modelo numérico foi desenvolvido no software Atena 3D.Gostaria de, se possível, agendar um encontro -informal- para conversamos sobre vossa experiência no processo de implantação do RI e mobilização da comunidade acadêmica. Estou à disposição para adequar-me aos seus horários entre os dia 30/11 a 04/12

Desenvolvimento de ferramenta vocacionada para o dimensionamento de estruturas metálicas de acordo com a NP EN 1993-1-1

Trabalho desenvolvido em parceria com a empresa Casais.A presente comunicação descreve o desenvolvimento de uma ferramenta informática vocacionada para o dimensionamento de estruturas metálicas de acordo com a NP EN 1993 1 1 [1]. A ferramenta AciariUM é direcionada para a verificação e dimensionamento (ELU) de vigas-coluna em aço sujeitas a flexão composta desviada. Foi desenvolvida como meio de análise de elementos em aço e de verificação expedita dos resultados recolhidos a partir de programas comerciais de análise estrutural. Permite ao utilizador um controlo total sobre os resultados, na medida em que todo o algoritmo e procedimento de cálculo relativo a cada parâmetro está disponível para consulta e edição.É dirigido um especial agradecimento: à CASAIS – Engenharia e Construção, S.A. e à Universidade do Minho por acolherem este projeto; aos suportes dos programas CYPE 3D e Robot Structural Analysis pela disponibilidade com que interagiram com os autores deste projeto sempre que a sua intervenção foi solicitada

Avaliação do comportamento de vigas mistas com conector Crestbond

Neste trabalho, realiza-se um estudo sobre vigas mistas em aço e betão onde se utilizam conectores do tipo Crestbond contínuos. O conector Crestbond consiste numa chapa plana lisa cortada em forma de crista com saliências e reentrâncias trapezoidais, pertencendo, por isso, à família dos conectores de chapa contínua. Anteriormente, já foi experimentalmente comprovado que o conector Crestbond apresenta elevada capacidade resistente, comportamento dúctil e capacidade para garantir o funcionamento misto pretendido [1]. No presente trabalho apresentam-se resultados de ensaios numéricos e experimentais em vigas mistas de aço e betão, realizados na Universidade do Minho, onde são utilizados conectores Crestbond

Flexural behaviour of an innovative connection for structural sandwich panels

This paper presents the results experimental work conducted with composite beam specimens that are part of a series of studies to determine the feasibility of using a new type of shear connector, called PERFOFRP, in Steel Fibre Reinforced Self-Compacting Concrete (SFRSCC) structural sandwich wall panels. The connector is consisted of a flat Glass Fiber Reinforced Polymer (GFRP) plate with aligned holes evenly distributed along its length. The perforated part of connector is embedded in the concrete layers and the connection is materialized by the combined effects of friction/adhesion and of the mechanical interlock between the perforated laminate and the concrete dowels formed by the concrete that pass through the holes. Previously, the authors of the present paper investigated the mechanical behaviour of connections made with PERFOFRP connectors under transversal loads. Nonetheless, up to now, no investigation was published on the flexural behaviour of sandwich panels produced with the PERFOFRP connectors. In the present paper, the overall mechanical behaviour of the connection under flexure was investigated, being reported: failure modes, stiffness and ultimate flexural capacities of composite beams. The impact of using connectors made with two different types of GFRP laminates were investigated on the mechanical behaviour of composite beams was investigated.BASF(undefined

Dynamic identification of paradela historic railway bridge

Paradela Bridge is a metallic bridge located along the bank of the Tua River in northern Portugal. While the bridge is not currently in service, its structure is representative of many metallic truss structures built across the country between the 19th and the 20th century. The construction of the Paradela Bridge was completed in 1886 and served for about 120 years connecting northern Portugal. Tua Line belongs to the Douro area that UNESCO recently declared as world heritage. This work acquires its importance since it might serve as an insight for the study of many other similar structures all over the country. This paper comprises a historic investigation of archived documents, an on-site survey to evaluate its present conditions, a dynamic testing and the construction and calibration of numerical models in finite element analysis software for structural assessment and capacity rating estimation(undefined

Evaluation of the inertia force in compressive impact loading on steel fiber-reinforced concrete

First Online: 05 September 2021Steel-fibre-reinforced concrete (SFRC) is a strain rate sensitive material and, therefore, its dynamic and static compressive behaviour can be significantly different. In the present study, the effect of loading rate on the compressive behaviour of SFRC with 1% hooked end steel fibres is experimentally investigated. During impact loading, an inertia force is created due to acceleration along the specimen, whose effect in the range of impact is studied for a comprehensive assessment of the dynamic analysis of SFRC structures. For the evaluation of the inertia force, an instrumented drop-weight test setup is used, which includes two fast response loadcells with capacities of 1000 and 2000 kN on top (impact force) and bottom (reaction force) of specimen. The drop-weight impact tests were performed with three different drop heights, corresponding to maximum strain rates that ranged from 1 to 50 s−1. Two high-capacity accelerometers (5000 g) were mounted in the middle of the cylindrical specimens to obtain the cylinder acceleration response. The results show that, by increasing the strain rates, compressive strength, maximum acceleration at the middle of cylinder, and inertia force are increased. The results in terms of the ratio between inertia and impact load of specimens are presented and discussed.The study reported in this paper is part of the project “PufProtec - Prefabricated Urban Furniture Made by Advanced Materials for Protecting Public Built” with the reference of (POCI-01-0145-FEDER-028256) supported by FEDER and FCT funds. The first author gratefully acknowledges the financial support of FCT-Fundação para a Ciência e Tecnologia for the Ph.D. Grant SFRH/BD/149246/2019