Yazar "Ersoy, Nuri" seçeneğine göre listele
Listeleniyor 1 - 6 / 6
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe 3D finite element model for predicting manufacturing distortions of composite parts(Sage Publications Ltd, 2016) Çınar, Kenan; Ersoy, NuriA 3D finite element model has been developed for predicting manufacturing distortions of fibre-reinforced thermosetting composite parts. The total curing process is divided into three steps that correspond to the states that resin passes through during curing: viscous, rubbery, and glassy. Tool-part interaction properties were calibrated by modelling the distortion of a single ply part. For comparison, composite parts of various geometries (L-section and U-section), stacking sequences, thicknesses, and bagging conditions were manufactured. The full field thickness profile and full field distortion pattern were obtained using a 3D laser scanner, which reveals higher and lower resin bleeding and corner thickening locations. The effect of stacking sequence is also examined with the full field distortion pattern. It was found that the parts manufactured under the bleeding condition give higher spring-in and warpage values. The spring-in predictions were well matched to measurements of the manufactured parts.Öğe A composite sandwich plate with a novel core design(Elsevier Sci Ltd, 2018) Uzal, Anıl; Sönmez, Fazıl O.; Öz, Fatih E.; Çınar, Kenan; Ersoy, NuriIn this study, a new core design is introduced for sandwich composite structures. Its strength and failure behavior are investigated via three-point bending tests. E-glass-fiber-reinforced epoxy resin is selected as the material for both the core and the face sheets. The core has an egg-crate shape. Acoustic emission (AE) method is used to detect the progression of damage. Signals due to elastic waves caused by activated damage mechanisms are investigated in order to identify the corresponding failure modes. A finite element model of the sandwich structure is developed to predict the failure behavior of the specimens under the loading conditions in the tests. A promising agreement between the results of the finite element model and the experiments is observed. The force-deflection-relation, the failure load as well as the region where damage initiates are accurately predicted.Öğe A Review on the Mechanical Modeling of Composite Manufacturing Processes(Springer, 2017) Baran, İsmet; Çınar, Kenan; Ersoy, Nuri; Akkerman, Remko; Hattel, Jesper H.The increased usage of fiber reinforced polymer composites in load bearing applications requires a detailed understanding of the process induced residual stresses and their effect on the shape distortions. This is utmost necessary in order to have more reliable composite manufacturing since the residual stresses alter the internal stress level of the composite part during the service life and the residual shape distortions may lead to not meeting the desired geometrical tolerances. The occurrence of residual stresses during the manufacturing process inherently contains diverse interactions between the involved physical phenomena mainly related to material flow, heat transfer and polymerization or crystallization. Development of numerical process models is required for virtual design and optimization of the composite manufacturing process which avoids the expensive trial-and-error based approaches. The process models as well as applications focusing on the prediction of residual stresses and shape distortions taking place in composite manufacturing are discussed in this study. The applications on both thermoset and thermoplastic based composites are reviewed in detail.Öğe Effect of residual stress on the bending response of L-shaped composite laminates(Elsevier Sci Ltd, 2020) Çınar, Kenan; Güven, İbrahim; Ersoy, Nuri[No Abstract Available]Öğe Experimental and numerical study of the tool-part interaction in flat and double curvature parts(European Conference on Composite Materials, ECCM, 2016) Yüksel, Onur; Çınar, Kenan; Ersoy, NuriA numerical model is developed to predict the process induced deformations of continuous fibre reinforced plastic plates which is made of AS4/8552 (Carbon fibre/epoxy) prepregs. In this way, Manufacturing costs can be reduced with elimination of trial and error approach. Sources of the process induced residual stress are clarified with the help of literature and implemented in 3D numerical model. In addition to the literature review to examine separate sources for residual stresses, an experimental measurement is conducted to observe tool part interaction which is quantified with strain gage which is embedded in prepreg. Numerical model is modified and verified with respect to overall deformation field of manufactured parts. Individual contribution of different mechanisms on overall deformation is discussed with the help of the numerical model. Moreover anisotropic friction between tool and the part is proposed to enhance the predictions of 3-D numerical model. © 2016, European Conference on Composite Materials, ECCM. All rights reserved.Öğe Failure Behavior of Corrugated Core Panel Under Out-Of-Plane Loading(Aalborg Univ Press, 2015) Çınar, Kenan; Öz, Fatih E.; Ersoy, NuriThe aim of this study is to investigate the failure behaviour of a panel with a novel corrugated core design under out-of-plane loading conditions. AS4/8552 prepreg system was used for both facesheet and core material and two different core designs are compared. Three-point bending tests were performed and acoustic emission monitoring technique was used to investigate the failure modes. It was observed that first matrix failure occurred at the corner sections of the panels and delamination initiated at these regions, followed by fibre failure at the ribs and facesheet. Acoustic emission signal clustering around certain frequencies was matched to various failure modes in order to provide an insight for further research on structural health monitoring by acoustic emission.
