The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Dong-yol Yang - One of the best experts on this subject based on the ideXlab platform.
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Investigation for the bending modes of a semi-circular pyramidal kagome sandwich structure and the bending load calculation
Composite Structures, 2015Co-Authors: June-sun Hwang, Tae-gyun Choi, Min-young Lyu, Dong-yol YangAbstract:Abstract Lattice-based sandwich structures are being widely investigated to meet increasing demands for lightweight components. In the recent research works, lattice-based open cell structures have exhibited higher specific strength compared to closed cell structures, such as a honeycomb structure. Generally, a kagome structure is more effective than other lattice structures for compression and bending. In this work, cross-sections of the strut of pyramidal kagome (PK) structure are developed to strengthen the sandwich structure. A PK structure based on a semi-circular cross-section (SCC) was applied to the bending load calculation. The bending deformation modes of the SCC-based PK sandwich structure were investigated. The bending load was calculated when the PK sandwich structure was bent as stable shear mode and the equation could express the non-linear elastic characteristics during the bending process by applying the effective shear modulus of inner PK cores. The calculated bending load–Deflection Curve was compared with the bending load–Deflection Curve obtained by FEM. The tendency of the calculated bending load–Deflection Curve was similar to the FEM result.
Zemei Wu - One of the best experts on this subject based on the ideXlab platform.
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effects of steel fiber content and shape on mechanical properties of ultra high performance concrete
Construction and Building Materials, 2016Co-Authors: Zemei Wu, Wen He, Linmei WuAbstract:Abstract This study investigated the effects of three shaped steel fibers (straight, corrugated, and hooked-end) with different fiber contents by volume (Vf = 0, 1%, 2%, and 3%) on mechanical properties of ultra high performance concrete (UHPC). The involved properties included flowability, compressive strength, and flexural behavior. According to the characteristics of the obtained three-point flexural load–Deflection Curve and the existing constitutive model of uniaxial compression, a new model for flexural load–Deflection based on least square fitting was proposed. The results indicated that increased fiber content and use of deformed fibers could gradually decrease the flowability of UHPC. They also had significant effects on compressive and flexural behavior of UHPC. With incorporation of 3% straight steel fibers, its compressive and flexural strengths reached over 150 and 35 MPa at 28 d. For the concrete with 3% hooked-end and corrugated fibers, the compressive strengths at 28 d increased by 48% and 59% compared to those with the same amount of straight fiber. Steel fiber content had limited effect on the first crack strength and first crack Deflection of flexural load–Deflection Curve of UHPC, but showed considerable effects on the peak load. The proposed model fitted well with the experimental results with correlation coefficient over 0.9.
Gokhan Tansel Tayyar - One of the best experts on this subject based on the ideXlab platform.
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Geometric Solution in Progressive Collapse Analysis of Hull Girder
Journal of Marine Science and Technology, 2014Co-Authors: Ertekin Bayraktarkatal, Gokhan Tansel TayyarAbstract:This paper presents a calculation model for stiffened plates to determine the ultimate strength of ship hull girders from their curvatures using a geometrical approach. The present study employed Smith's method, in which the cross-section is divided into smaller elements consisting of a stiffener(s) and attached plating. The strength of beam-columns and stiffened plates was obtained using an iterative numerical approach. The Deflection Curve was evaluated using the curvature values directly instead of by solving differential equations. The Deflection Curve was taken as an assembly of chains of circular arcs. The ultimate strength of the hull girder of a 1/3 scaled frigate model was analyzed using the proposed method through an iterative approach. The present method produced reasonably accurate solutions with low modeling and computational times.
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new analytical method with curvature based kinematic Deflection Curve theory
International Journal of Ocean System Engineering, 2012Co-Authors: Gokhan Tansel TayyarAbstract:This paper reports a new analytical method to calculate the planar displacement of structures. The cross-sections were assumed to remain in plane and the Deflection Curve was evaluated using the curvature values geometrically, despite being solved with differential equations. The Deflection Curve was parameterized with the arc-length of the curvature values, and was taken as an assembly of chains of circular arcs. Fast and accurate solutions of complex Deflections can be obtained easily. This paper includes a comparison of the nonlinear displacements of an elastic tapered cantilever beam with a uniform moment distribution among the proposed analytical method, numerical method of the theory and large Deflection FEM solutions.
Valentina Lopresto - One of the best experts on this subject based on the ideXlab platform.
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Elastic behaviour of circular composite plates transversely loaded at the centre
Composites Part A: Applied Science and Manufacturing, 2002Co-Authors: G. Caprino, Antonio Langella, Valentina LoprestoAbstract:Abstract Static tests were carried out on moderately anisotropic, simply supported circular plates made of graphite fibre reinforced plastic laminates of various thicknesses, loading them at the centre by a hemispherical tup. A non-linear solution available for large Deflections of isotropic plates was suitably modified to account for the Hertzian contact phenomena, and adopted to model the plate behaviour in the elastic field. From the experimental results, an unacceptable error is made in predicting the force–Deflection Curve up to first failure, if the non-linear portion of the Deflection is neglected. This error is the more evident when thin laminates are concerned. For thick laminates, the Hertzian contact plays a significant role in affecting the plate behaviour. Taking into account both the local deformation and non-linearity due to large Deflections, a very accurate prediction of the load–Deflection Curve was obtained. Only in the case of the thinnest composites tested, a divergence of the theoretical Curve from the experimental data was observed at sufficiently high loads. The analysis of the failure modes revealed that the discrepancy is seemingly attributable to internal damage not resulting in clearly discernible discontinuities in the load–Deflection Curve.
Izabela Musiał - One of the best experts on this subject based on the ideXlab platform.
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Application of a compliant foil bearing for the thrust force estimation in the single stage radial blower
Open Engineering, 2015Co-Authors: Jakub Łagodziński, Kacper Miazga, Izabela MusiałAbstract:AbstractThe paper presents the application of a compliant foil bearing for estimation of the thrust force in a single stage radial blower under operational conditions. The bump foil of the thrust bearing behaves as a nonlinear spring. The knowledge of the spring Deflection Curve allows estimation of the actual thrust force for a measured bump Deflection at the given rotational speed. To acquire the Deflection Curve, static calibration of the axial shaft displacement sensor was performed. During the calibration, the information about voltage signals of the sensor for the given loading force was collected. The measured voltage values at different speeds and loadswere then converted into the thrust force. The results were verified by comparison to the thrust force resulting from the pressure distribution on the impeller.