1,721,010 research outputs found
DESIGN OF FIBRE-POLYMER COMPOSITE STRUCTURES (CEN/TS 19101): ULS ANALYSIS OF A SPATIAL RETICULAR STRUCTURE
Full text linkPresented in this paper is a worked example to demonstrate the practical application of the CEN European Technical Specification CEN/TS 19101:2022 when designing a spatial reticular structure that has been constructed inside the Santa Maria Paganica church, Italy, following severe damaged by the 2009 L’Aquila earthquake. The example showcases the use of fibre-polymer composites to create a lightweight, resilient shelter that ensures the structural integrity and seismic safety over the time interval necessary for restoration of the damaged church. This worked example summarizes the structural analysis and ULS verification checks carried out to meet the requirements of CEN/TS 19101, thereby emphasizing its effectiveness in facilitating the design process to safeguard historic sites during restoration projects.Paper 159: Special Session on Design of all FRP Structures Using CEN/TS 1910
Does performance based design with fibre reinforced polymer components and structures provide any new benefits and challenges?
No full textReviewing the current status towards the exploitation of fibre reinforced polymers (FRPs) in structural engineering the author considers the benefits and challenges for using performance based design with this newer construction material. This paper reports historical case studies in the context of explaining how processing technologies and design know-how have slowly been developing, and perhaps even leading to a level of maturity. By way of the review of FRP components and structures it is found that we do not yet possess the prescriptive rules that dominate the current execution of civil engineering works. One outcome from the review is to identify that such rules will be necessary to allow routine design of frame structures of universal (standard) FRP shapes. The author introduces the benefits and challenges towards the adoption of Performance Based Design (PBD) and finds that targeted research and development has/is using the PBD philosophy to produce bespoke FRP components and systems towards a growing number of applications in structural engineering
Design guidance for bolted connections in structures of pultruded shapes: gaps in knowledge
No full textThe purpose of this paper is to introduce a brand new standard for the design of frame structures of pultruded Fibre-Reinforced Polymer (FRP) shapes, with an emphasis on the gaps in knowledge towards the mandatory design information for bolted connections. Structural engineering designers facing fee competition and unrealistic deadlines seek design methods that are simple to use and on the ‘safe’ side. They often have little knowledge of exactly ‘how safe’ their designs are, and with too little time to
find out they will confidently follow a code of practice when working with a traditional structural material. Structural shapes of FRP have been available since the 1970s and, for this non-traditional material, designers have had to rely on information from the pultruders, since there is no code of practice to follow. Because this is an obstacle to market growth a project commenced in 2007 to write an American Society of Civil Engineers standard. As part of a team of ‘code writers’ the author works on the design guidance for a chapter on bolted connections. By way of a critical evaluation of what we know, and don’t know, the team has gained insight into where new academic research is required to cope with deficiencies in our knowledge and understanding. This paper lists twenty questions that require our attention and it provides advice on how they should be tackled to ensure that the research is not useless; ‘useless’ in the sense that results cannot be used for the basis of preparing design guidance
Rationale for simplifying the strength formulae for the design of multi-row bolted connections failing in net tension
Full text linkHart-Smith [1] developed a set of closed form strength formulae for a semi-empirical approach to determine the net tension strength of multi-row bolted connections with composite materials. Mottram [2] showed that, for a pultruded fibre reinforced polymer material, the approach to be reliable (and conservative) for the configuration comprising two rows with a single bolt per row. This led to the formulae being developed into clauses in an American pre-standard for Load and Resistance Factor Design (LRFD) of Pultruded Fiber-Reinforced Polymer (FRP) Structures [3]. Because the expressions in the Hart-Smith formulae are not simple, the message coming from the practitioners, on the ASCE/SEI Fiber Composites And Polymers Standards committee (FCAPS) tasked with developing the pre-standard [3] into a standard, is that they would not use them when designing bolted connections. Taking stock of the specified geometries, bolt details and design parameters permitted by the pre-standard [3] the author conducted an analytical
parametric study using the Hart-Smith formulae with the aim of establishing simplified forms that could be routinely used in the design office. Presented in this paper is the provenance to this code-specific work when the connection has more than a single row of bolts. A presentation is given to what has been lost, in terms of calculated net tension strength, by providing the
simplified strength formula in the mandatory part to the standard. To enable the designer to be able to take full advantage of the Hart-Smith design approach [1, 2], the ‘complicated’ formulae and their accompanying mandatory-style text are to be found in an appendix with the standard’s commentary [3]
Fire testing of insulated RC beams strengthened with NSM reinforcement
No full textThe weak performance of fibre reinforced polymer (FRP) strengthened members in fire is a primary factor hindering the widespread implementation of FRP strengthening technology in the construction industry. FRP strengthening is critically dependent upon the bonding adhesive. The polymer resins (ambient cured epoxies) currently used as primers, adhesive and matrixes for FRP soften at temperatures in the range of their glass transition temperature and consequently their integrity can be lost during fire. To evaluate the feasibility of achieving a fire-rated FRP system an investigation was undertaken to examine and document the performance of near-surface mounted (NSM) FRP strengthened concrete beams under fire conditions. The experimental program consisted of fire tests on full-scale reinforced concrete beams that were strengthened in flexure with NSM FRP bars and insulated with different insulation systems. The specimens were subsequently exposed to a standard fire while submitted to their service load. Member deflections and temperatures throughout the section were measured during the fire testing. Tests results on fire indicated that insulated NSM FRP strengthened beams can achieve a satisfactory fire endurance of at least two hours, through the contribution of the FPR is generally lost early. Depending on the fire insulation system efficiency, the FRP strengthening may be kept intact during fire, for this test prograum up to 60 minutes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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