Pull-out behaviour of glass-fibre reinforced polymer perforated plate connectors embedded in concrete. Part II: Prediction of load carrying capacity

The authors have recently proposed an innovative connector system that consists on a Glass Fibre Reinforced Polymer (GFRP) perforated plate that is embedded into Steel Fibre Reinforced Self Compacting Concrete (SFRSCC) layers. The connection is strongly based in the mechanical interlock assured by the dowels originated from the SFRSCC passing through the holes opened on the GFRP plates. In this study, an analytical framework to evaluate the load capacity of the connections when loaded transversally was developed based on experimental pull-out tests presented in the companion paper (Part I). For a better understanding of the mechanical behaviour of the connections and to allow to make estimations of the load capacity of connection when it is conditioned by the rupture of the connector itself, pull-out pin-bearing tests with single-hole plates were executed to assess the effect of the type of GFRP on the strain distribution in the vicinity of the holes until the failure, as well as the estimated failure modes and load capacities of the connections.- This work is part of the research project QREN number 5387, LEGOUSE, involving the companies Mota-Engil, CiviTest, the ISISE/University of Minho and PIEP. The first author would like to thank the financial support provided by PAIP/UNILA. The second author wish to acknowledge the grant SFRH/BSAB/114302/2016 provided by FCT.info:eu-repo/semantics/publishedVersio

Diagnostic accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis: An international case-cohort study

We conducted an international study of idiopathic pulmonary fibrosis (IPF) diagnosis among a large group of physicians and compared their diagnostic performance to a panel of IPF experts. A total of 1141 respiratory physicians and 34 IPF experts participated. Participants evaluated 60 cases of interstitial lung disease (ILD) without interdisciplinary consultation. Diagnostic agreement was measured using the weighted kappa coefficient (\u3baw). Prognostic discrimination between IPF and other ILDs was used to validate diagnostic accuracy for first-choice diagnoses of IPF and were compared using the Cindex. A total of 404 physicians completed the study. Agreement for IPF diagnosis was higher among expert physicians (\u3baw=0.65, IQR 0.53-0.72, p20 years of experience (C-index=0.72, IQR 0.0-0.73, p=0.229) and non-university hospital physicians with more than 20 years of experience, attending weekly MDT meetings (C-index=0.72, IQR 0.70-0.72, p=0.052), did not differ significantly (p=0.229 and p=0.052 respectively) from the expert panel (C-index=0.74 IQR 0.72-0.75). Experienced respiratory physicians at university-based institutions diagnose IPF with similar prognostic accuracy to IPF experts. Regular MDT meeting attendance improves the prognostic accuracy of experienced non-university practitioners to levels achieved by IPF experts

The effects of geometric parameters on the failure strength for pin-loaded multi-directional fiber-glass reinforced epoxy laminate

A numerical and experimental study was carried out to determine the failure of mechanically fastened fiber-reinforced laminated composite joints. E/glass-epoxy composites were manufactured to fabricate the specimens. Mechanical properties and strengths of the composite were obtained experimentally. Tests have been carried out on single pinned joints in [0/90/0](s) and [90/0/90](s) laminated composites. A parametric study considering geometries was performed to identify the failure characteristics of the pin-loaded laminated composite. Data obtained from pin-loaded laminate tests were compared with the ones calculated from a finite element model (PDNLPIN computer code). Damage accumulations in the laminates were evaluated by using Hashin's failure criteria combined with the proposed property degradation model. Based on the results, ply orientation and geometries of composites could be crucial for pinned laminated composite joints. (C) 2002 Published by Elsevier Science Ltd

The failure strength for pin-loaded multi-directional fiber-glass reinforced epoxy laminate

In this study, failure characteristics of laminated composites loaded by means of a single fastener were investigated. The development and evaluation of joint capability for both failure mode and ultimate load are the major aims. Tests have been carried out on single pinned joints in multi-directional glass-fiber reinforced epoxy for a range of laminate configurations and specimen geometry. For [90/0](2s), and [+/-45](2s) laminates with single-hole joints the strengths have been measured; the effects of variables such as ply orientation, laminate edge and side distances were discussed in the light of the results. In addition, by using finite element code PDNLPIN, a static progressive failure analysis was performed. Comparisons were made between the test data and the results of the model. The effect of material nonlinearity on the prediction of the failure loads was studied. Good agreement was found between numerical predictions and the experimental data

The strength of pinned joints in laminated composites

An investigation was performed to study the response of pin-loaded laminated composites. Tensile tests were performed on E/ glass-epoxy composites for two different ply orientations such as [0/+/-45](s) and [90/+/-45](s). For each ply orientation, 20 different geometries were chosen. The major focus of the study was to characterize the failure mechanisms and to evaluate the effect of geometric dimensions on the bearing, shear-out and net-tension strengths of pinned joints. For this purpose, the specimens were tested to find first failure and final failure load. In addition, by using finite element code PDNLPIN, a static progressive failure analysis was performed. The effect of the material non-linearity was taken into account on the mathematical forms. Comparisons were made between the test data and the results of the model and these showed good agreements. (C) 2003 Elsevier Science Ltd. All rights reserved

The effect of ply number, orientation angle and bonding type on residual stresses of woven steel fiber reinforced thermoplastic laminated composite plates subjected to transverse uniform load

This paper is concerned with the numerical results of the elasto-plastic stress analysis and residual stresses in woven steel fiber reinforced thermoplastic laminated composite plates for transverse uniform loads. The effects of ply number, orientation angle and bonding type on the residual stresses of laminated composite plates are investigated. Elasto-plastic stress analysis is carried out in the laminated plate by using the finite element technique. The finite element code ANSYS is used to perform the numerical analyses using an eight-node layered shell element. Yielding loads and residual stresses are obtained for symmetric and anti-symmetric laminated plates with simply supported boundary conditions. Different stacking sequences of laminated composites are used in analysis and the results are compared with each other. Three load steps are carried out for each analysis consecutively. In the first load step, the yielding transverse load is applied. Secondly, a series of load increments is added until the load reaches "Yielding Load+ 0.005 NIPa". In the last step the external load is released to obtain the residual stress components. (C) 2003 Elsevier Ltd. All rights reserved

A study of the effects of various geometric parameters on the failure strength of pin-loaded woven-glass-fiber reinforced epoxy laminate

The aim of this study is to examine the effects of woven fiber, specimen width-to-hole diameter ratio (W/D), and the ratio of edge distance to hole diameter (E/D) on the bearing strength of woven laminated composites. Glass/epoxy composites were manufactured under pressure by moulds at 120 degreesC. The mechanical properties and strengths of the composites were obtained experimentally. The glass/epoxy woven composites were loaded through pins. Single-hole pin-loaded specimens were tested for their tensile response and W/D and E/D ratios evaluated. Failure propagation and failure type were observed on the specimens. The influence of the joint geometry on the strength of the pin-loaded composites was assessed. The experimental results show that the ultimate load capacity of woven-glass-fiber. reinforced epoxy laminates with pin connections was increased by increasing W and E. However increasing the E/D ratio beyond 2 and increasing the W/D ratio beyond 3 have an insignificant effect on the ultimate load capability of the connection. (C) 2001 Published by Elsevier Science Ltd. All rights reserved

Analytical study of clamped steel fiber reinforced aluminum metal matrix composite including elasto-plastic behavior

The elasto-plastic behaviour of steel fiber reinforced aluminum metal matrix composite with five different orientations has been investigated, including the effect of single force. A composite beam with a rectangular cross section is fixed at one end and is bent by a transverse force P applied to the free end. To determine analytically, residual stresses and the expansion of plastic zone for different orientation angles a software program is developed and this program makes it possible to establish elastic region, plastic region, the distributions of the residual stress component, the distance between the free end and yield points for 0degrees, 30degrees, 45degrees, 60degrees and 90degrees orientation angles. To verify the analytical solutions, the sophisticated finite element code such as ANSYS 5.6 was used to perform numerical analyses