The Experts below are selected from a list of 36888 Experts worldwide ranked by ideXlab platform
Jun Liu - One of the best experts on this subject based on the ideXlab platform.
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precise bending stress analysis of corrugated core honeycomb core and x core sandwich panels
Composite Structures, 2012Co-Authors: Yuansheng Cheng, Jun LiuAbstract:Abstract A semi-analytical method for bending analysis of corrugated-core, honeycomb-core and X-core sandwich panels is presented. The Real Displacement of sandwich panels is divided into the global Displacement field and local Displacement field. The discrete geometric nature of the core is taken into account by treating the core sheets as beams and the sandwich panel as composite structure of plates and beams with proper Displacement compatibility. In the global Displacement field, the governing equations of these sandwich panels are derived using energy variation principle and solved by employing Fourier series and the Galerkin approach. In the local Displacement field, the face sheets under external loads are taken as a multi-span thin plate and the local bending response are then computed. Then the Real bending responses are obtained by superposing these bending responses calculated in the two Displacement fields and the structural stress fluctuation can be captured. Results from the proposed method agree well with available results in the literature and those from detailed finite element analysis. Furthermore, the mechanical properties of the three kinds of sandwich panels have been compared.
Chunte Chen - One of the best experts on this subject based on the ideXlab platform.
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coseismic deformation time history calculated from acceleration records using an emd derived baseline correction scheme a new approach validated for the 2011 tohoku earthquake
Bulletin of the Seismological Society of America, 2013Co-Authors: Jyunyan Huang, Kuoliang Wen, Junju Xie, Chunte ChenAbstract:Abstract Displacement time histories from double‐integrated accelerograms typically cannot be used to recover near‐field terms because of noise in the acceleration traces. To minimize this problem, empirical mode decomposition (EMD) is used to derive a baseline correction scheme. The scheme is tested against several models composed of a single frequency or two frequencies and offsets in acceleration. It is verified against Real Displacement time history using Global Positioning Systems (GPS) measurement. For single‐ and double‐frequency‐content models, obvious discontinuities are found at drift times for lower intrinsic mode function (IMF) components. A drift model, however, can be clearly found from summing higher IMFs and the residuals of simple frequency‐content waveform models. On the other hand, results show that the lesser frequency‐content signal has the greater decomposed result. Therefore, a suitable corner frequency for low‐pass filtering is first implemented to reduce frequency content. In this case, the trend in the given drift model is easily found by summing higher IMFs for a complex frequency content model (model 3 of this study). A suitable corner frequency for low‐pass filtering is attained using a grid‐search method. A new semiautomatic EMD‐derived baseline correction scheme is tested. The corrected coseismic deformation value (CDV, denoted hereafter as from preevent Displacement to the final offset during strong motion), peak ground Displacement, and Displacement time history from this method have good agreement with 1‐Hz continuous GPS measurement for the 2011 Tohoku earthquake.
Yuansheng Cheng - One of the best experts on this subject based on the ideXlab platform.
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precise bending stress analysis of corrugated core honeycomb core and x core sandwich panels
Composite Structures, 2012Co-Authors: Yuansheng Cheng, Jun LiuAbstract:Abstract A semi-analytical method for bending analysis of corrugated-core, honeycomb-core and X-core sandwich panels is presented. The Real Displacement of sandwich panels is divided into the global Displacement field and local Displacement field. The discrete geometric nature of the core is taken into account by treating the core sheets as beams and the sandwich panel as composite structure of plates and beams with proper Displacement compatibility. In the global Displacement field, the governing equations of these sandwich panels are derived using energy variation principle and solved by employing Fourier series and the Galerkin approach. In the local Displacement field, the face sheets under external loads are taken as a multi-span thin plate and the local bending response are then computed. Then the Real bending responses are obtained by superposing these bending responses calculated in the two Displacement fields and the structural stress fluctuation can be captured. Results from the proposed method agree well with available results in the literature and those from detailed finite element analysis. Furthermore, the mechanical properties of the three kinds of sandwich panels have been compared.
Jyunyan Huang - One of the best experts on this subject based on the ideXlab platform.
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coseismic deformation time history calculated from acceleration records using an emd derived baseline correction scheme a new approach validated for the 2011 tohoku earthquake
Bulletin of the Seismological Society of America, 2013Co-Authors: Jyunyan Huang, Kuoliang Wen, Junju Xie, Chunte ChenAbstract:Abstract Displacement time histories from double‐integrated accelerograms typically cannot be used to recover near‐field terms because of noise in the acceleration traces. To minimize this problem, empirical mode decomposition (EMD) is used to derive a baseline correction scheme. The scheme is tested against several models composed of a single frequency or two frequencies and offsets in acceleration. It is verified against Real Displacement time history using Global Positioning Systems (GPS) measurement. For single‐ and double‐frequency‐content models, obvious discontinuities are found at drift times for lower intrinsic mode function (IMF) components. A drift model, however, can be clearly found from summing higher IMFs and the residuals of simple frequency‐content waveform models. On the other hand, results show that the lesser frequency‐content signal has the greater decomposed result. Therefore, a suitable corner frequency for low‐pass filtering is first implemented to reduce frequency content. In this case, the trend in the given drift model is easily found by summing higher IMFs for a complex frequency content model (model 3 of this study). A suitable corner frequency for low‐pass filtering is attained using a grid‐search method. A new semiautomatic EMD‐derived baseline correction scheme is tested. The corrected coseismic deformation value (CDV, denoted hereafter as from preevent Displacement to the final offset during strong motion), peak ground Displacement, and Displacement time history from this method have good agreement with 1‐Hz continuous GPS measurement for the 2011 Tohoku earthquake.
David C Tanner - One of the best experts on this subject based on the ideXlab platform.
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evolution of a fault surface from 3d attribute analysis and Displacement measurements
Journal of Structural Geology, 2008Co-Authors: T Lohr, Charlotte M Krawczyk, Onno Oncken, David C TannerAbstract:Abstract A large fault surface evolves by growth and coalescence of numerous segments through time, which results in strong undulations of the principal fault surface. We interpreted a strongly segmented, 13 km long fault using 3D seismic data, and studied the morphology in terms of fault linkage, using curvature, azimuth, and dip attributes. Displacement profiles of two horizons were measured to analyse the different Displacement relations and to quantify their variation and dependence on fault morphology. We identified four orders of fault segments over a scale range from a few hundred metres to several kilometres, which evolved during fault growth. The strong changes in orientation of the several segments might result in a heterogeneous small-scale fracture distribution and different fault drag geometries. Displacement measurements on the undulated fault surface indicate a strong variation between Real, vertical, and horizontal Displacement values. However, the commonly used throw values lead to a smoothing of the Real Displacement curves and to an underrepresentation of their values, and therefore cannot show a triangular shape that is typically identified from ruptures fault surfaces of earthquake processes. Therefore, for any kind of fault analysis care should be taken when using throw as approximation for the Real Displacement.
