The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform
Guangyong Sun - One of the best experts on this subject based on the ideXlab platform.
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experimental and numerical study on honeycomb sandwich Panels under bending and in Panel compression
Materials & Design, 2017Co-Authors: Guangyong Sun, Xintao Huo, Dongdong ChenAbstract:Abstract Sandwich structures have been extensively employed as lightweight composite components in aerospace and shipbuilding engineering for their high capacity of stiffness, strength and energy absorption. To explore the crushing behaviors of honeycomb sandwiches, both three-point bending (TPB) and in-Panel compression (IPC) tests were performed on aluminum honeycomb sandwich Panels in this study. The effects of several key structural parameters on crashworthiness characteristics and collapse mechanism were first explored through the experiments here. The experimental results divulged that crashworthiness and collapse mode of sandwich structures were greatly influenced by the structural parameters under the TPB test. The crash behaviors can be also affected by both structural and adhesive parameters in the IPC test. Through validating with the experimental data, the numerical models were established to capture some deformation and failure details in the crushing processes. Taking into account the adhesive interface in the finite element (FE) model, glue debonding was simulated for the IPC loading, which is in good agreement with the experimental results at the Skin Panel buckling. Based on the experimental results, theoretical solutions for the TPB test were also established to predict the peak load, energy absorption and collapse mode. This study provided a new basis for the further studies on the crashworthiness optimization of sandwich structures.
Peretz P Friedmann - One of the best experts on this subject based on the ideXlab platform.
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an aerothermoelastic analysis framework with reduced order modeling applied to composite Panels in hypersonic flows
Journal of Fluids and Structures, 2020Co-Authors: Daning Huang, Peretz P FriedmannAbstract:Abstract This study describes the enhancement of a computational framework for aerothermoelasticity using novel model order reduction techniques and efficient coupling schemes. First, the fluid solver for hypersonic aerothermodynamics is accelerated using a reduced order model. The flexibility of the reduced order model is enhanced using a novel correction and scaling technique, which accounts for non-uniform temperature distribution, varying flight conditions and geometrical scales using analytical pointwise models. Secondly, based on the reduced order model, a tightly-coupled scheme and linearized stability analysis are developed for fast aerothermoelastic simulation of extended flight time and automatic identification of aerothermoelastic instabilities, respectively. The enhanced framework is accelerated by a factor of 1 0 4 so that near-real-time aerothermoelastic simulation is achieved. Finally, using the enhanced framework, the aerothermoelastic response of a generic Skin Panel is studied emphasizing the effect of flow orientation angle and material orthotropicity on the aerothermoelastic stability boundary. It is found that a combination of flow orientation angle and material orientation can significantly extend the aerothermoelastic stability boundary, i.e. the time elapsed before the onset of structural failure.
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aerothermoelastic scaling laws for hypersonic Skin Panel configurations with arbitrary flow orientation
AIAA Journal, 2018Co-Authors: Daning Huang, Peretz P Friedmann, Tomer RokitaAbstract:This study describes the development of an efficient aerothermoelastic computational framework and its application to the aerothermoelastic scaling law development. In the framework, a novel approa...
Dongdong Chen - One of the best experts on this subject based on the ideXlab platform.
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experimental and numerical study on honeycomb sandwich Panels under bending and in Panel compression
Materials & Design, 2017Co-Authors: Guangyong Sun, Xintao Huo, Dongdong ChenAbstract:Abstract Sandwich structures have been extensively employed as lightweight composite components in aerospace and shipbuilding engineering for their high capacity of stiffness, strength and energy absorption. To explore the crushing behaviors of honeycomb sandwiches, both three-point bending (TPB) and in-Panel compression (IPC) tests were performed on aluminum honeycomb sandwich Panels in this study. The effects of several key structural parameters on crashworthiness characteristics and collapse mechanism were first explored through the experiments here. The experimental results divulged that crashworthiness and collapse mode of sandwich structures were greatly influenced by the structural parameters under the TPB test. The crash behaviors can be also affected by both structural and adhesive parameters in the IPC test. Through validating with the experimental data, the numerical models were established to capture some deformation and failure details in the crushing processes. Taking into account the adhesive interface in the finite element (FE) model, glue debonding was simulated for the IPC loading, which is in good agreement with the experimental results at the Skin Panel buckling. Based on the experimental results, theoretical solutions for the TPB test were also established to predict the peak load, energy absorption and collapse mode. This study provided a new basis for the further studies on the crashworthiness optimization of sandwich structures.
K Hudson - One of the best experts on this subject based on the ideXlab platform.
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guided wave propagation in honeycomb sandwich structures using a piezoelectric actuator sensor system
Smart Materials and Structures, 2009Co-Authors: F Song, G L Huang, K HudsonAbstract:Due to the complex nature of such composite structures, an understanding of the guided wave propagation mechanism in honeycomb composite Panels with different frequencies inherently imposes many challenges. In this paper, a numerical simulation is first conducted to investigate the wave propagation mechanism in honeycomb sandwich structures using piezoelectric actuators/sensors. In contrast to most of the previous work, elastic wave responses based on the real geometry of the honeycomb core are obtained by using the finite element method (FEM). Based on the simulation, the global guided waves in the composite can be observed when the loading frequency is low and the leaky guided waves in the Skin Panel are found when the loading frequency is sufficiently high. The applicability of the homogenization technique for a celled core is discussed. The effects of cell geometry on the wave propagation are also demonstrated. Experimental testing is finally conducted to validate the results of numerical simulation and very good agreement is observed. Specifically, some guided wave propagation characteristics such as group velocity dispersion and mode tuning capabilities with the presence of a honeycomb core are discussed.
Flavio D Marques - One of the best experts on this subject based on the ideXlab platform.
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on the effects of structural coupling on the supersonic flutter and limit cycle oscillations of transversely reinforced Panels
Journal of Fluids and Structures, 2018Co-Authors: Douglas R Q Pacheco, A J M Ferreira, Flavio D MarquesAbstract:Abstract Panel flutter is an aeroelastic phenomenon that can critically affect aircraft Skin in supersonic flight. The majority of works published on this subject treat each Skin Panel as an isolated structural element. In reality, however, aircraft Skin is usually built as large Panels stiffened by stringers and frames. Thus, the multiple subPanels sitting between stiffeners are structurally coupled rather than isolated, and therefore can interact during flutter. In the present work, a reinforced Panel is simulated as a rectangular plate reinforced by an elastic beam that “subdivides” the Panel into two square subPanels (bays). The Panel is modeled as a Mindlin–vonKarman plate, and the stiffener as a nonlinear eccentric Timoshenko beam. The problem is discretized through the Finite Element Method, and the resulting nonlinear equations of motion are solved via numerical time-marching. This approach is a higher-fidelity extension to the methodology employed by the authors in previous works, where the stiffeners were idealized as immovable simple supports – the so-called multibay model. The present results are compared to those from both the multibay model and the single-Panel model. Each bay in the stiffened Panel is identical to the reference single Panel. Results are produced for several stiffener cross-sectional aspect ratios, r . Linear flutter boundary results show that, as r increases, the critical dynamic pressure asymptotically approaches that of a single Panel. Nonlinear post-flutter analyses reveal the occurrence of jump discontinuities in the limit cycle amplitude diagrams. Similarly to what has been seen in the literature for multibay Panels, the jumps are related to the nonlinear structural coupling between neighboring bays, and occur when there is a shift in the flutter mechanism. Furthermore, it is shown that reducing the cross-sectional aspect ratio postpones not only the onset of flutter but also the jumps, which can be avoided for sufficiently small r . Important engineering design guidelines can be established from the present study, as the multibay and single-Panel models are shown to be generally conservative regarding linear behavior, but potentially unsafe in the post-flutter regime.