Parametric Study on Compression Deformation Behavior of Conformal Load-Bearing Smart Skin Antenna Structure

2004 ◽  
Vol 261-263 ◽  
pp. 663-668 ◽  
Author(s):  
Kwang Joon Yoon ◽  
Young Suk Kim ◽  
Young Bae Kim ◽  
J.D. Lee ◽  
Hyun Chul Park ◽  
...  

In this paper, a simple conformal load-bearing antenna structure smart skin with a multi-layer sandwich structure composed of carbon/epoxy, glass/epoxy, and a dielectric polymer was designed and fabricated. The mechanical properties of each material in the designed smart skin were obtained from experiments. Tests and analyses were conducted to study the behavior of the smart skin under compressive loads. The designed smart skin failed due to buckling before compression failure. The stresses of each layer and the first failed layer of the smart skin were predicted using MSC/NASTRAN. The finite element model was verified by comparing the numerical results from geometrical linear/nonlinear analyses with the measured data. The numerically predicted structural behavior of the smart skin agreed well with the experimental data. The results showed that the carbon/epoxy layer took charge of most of the compressive load, and the first failure occurred in the dielectric layer while the other layers remained safe. A numerical model was used to obtain design data from the parametric study. The effect of changing the design variables on the buckling and compressive behavior of the smart skin was also investigated. As a result, it was confirmed that the transverse shear moduli of the honeycomb core had a serious impact on the buckling load of the smart skin when the shear deformation was considerable.

2006 ◽  
Vol 321-323 ◽  
pp. 963-967 ◽  
Author(s):  
June Sung Joe ◽  
Hoon Cheol Park ◽  
Kwang Joon Yoon ◽  
Nam Seo Goo

In this paper, a smart skin, i.e. a conformal load-bearing antenna structure, which is a multi-layer sandwich structure composed of carbon/epoxy, glass/epoxy and dielectric material, designs, analyses, fabrications and tests are conducted. Mechanical properties of each structural layer of the designed smart skin are obtained from experimental tests. Tests and analyses are conducted to study the deformation behavior of the smart skin under compressive loads. The measured data are compared with the numerical results from geometrically linear/nonlinear finite element analyses. Numerical prediction for the buckling load of the smart skin agreed well with the experimental data.


1999 ◽  
Author(s):  
Jonathan Bartley-Cho ◽  
Allen Lockyer ◽  
Kevin Alt ◽  
Daniel Coughlin ◽  
Jayanth Kudva ◽  
...  

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 173-180
Author(s):  
Giorgia Di Gangi ◽  
Giorgio Monti ◽  
Giuseppe Quaranta ◽  
Marco Vailati ◽  
Cristoforo Demartino

The seismic performance of timber light-frame shear walls is investigated in this paper with a focus on energy dissipation and ductility ensured by sheathing-to-framing connections. An original parametric finite element model has been developed in order to perform sensitivity analyses. The model considers the design variables affecting the racking load-carrying capacity of the wall. These variables include aspect ratio (height-to-width ratio), fastener spacing, number of vertical studs and framing elements cross-section size. A failure criterion has been defined based on the observation of both the global behaviour of the wall and local behaviour of fasteners in order to identify the ultimate displacement of the wall. The equivalent viscous damping has been numerically assessed by estimating the damping factor which is in use in the capacity spectrum method. Finally, an in-depth analysis of the results obtained from the sensitivity analyses led to the development of a simplified analytical procedure which is able to predict the capacity curve of a timber light-frame shear wall.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3346
Author(s):  
Bora Gencturk ◽  
Hadi Aryan ◽  
Mohammad Hanifehzadeh ◽  
Clotilde Chambreuil ◽  
Jianqiang Wei

In this study, an investigation of the shear behavior of full-scale reinforced concrete (RC) beams affected from alkali–silica reactivity damage is presented. A detailed finite element model (FEM) was developed and validated with data obtained from the experiments using several metrics, including a force–deformation curve, rebar strains, and crack maps and width. The validated FEM was used in a parametric study to investigate the potential impact of alkali–silica reactivity (ASR) degradation on the shear capacity of the beam. Degradations of concrete mechanical properties were correlated with ASR expansion using material test data and implemented in the FEM for different expansions. The finite element (FE) analysis provided a better understanding of the failure mechanism of ASR-affected RC beam and degradation in the capacity as a function of the ASR expansion. The parametric study using the FEM showed 6%, 19%, and 25% reduction in the shear capacity of the beam, respectively, affected from 0.2%, 0.4%, and 0.6% of ASR-induced expansion.


2019 ◽  
Vol 6 (2) ◽  
pp. 43 ◽  
Author(s):  
Harold J. Brandon ◽  
Larry S. Nichter ◽  
Dwight D. Back

The IDEAL IMPLANT® Structured Breast Implant is a dual lumen saline-filled implant with capsular contracture and deflation/rupture rates much lower than single-lumen silicone gel-filled implants. To better understand the implant’s mechanical properties and to provide a potential explanation for these eight-year clinical results, a novel approach to compressive load testing was employed. Multi-dimensional strains and tangent moduli, metrics describing the shape stability of the total implant, were derived from the experimental load and platen spacing data. The IDEAL IMPLANT was found to have projection, diametric, and areal strains that were generally less than silicone gel implants, and tangent moduli that were generally greater than silicone gel implants. Despite having a relatively inviscid saline fill, the IDEAL IMPLANT was found to be more shape stable compared to gel implants, which implies potentially less interaction with the capsule wall when the implant is subjected to compressive loads. Under compressive loads, the shape stability of a higher cross-link density, cohesive gel implant was unexpectedly found to be similar to or the same as a gel implant. In localized diametric compression testing, the IDEAL IMPLANT was found to have a palpability similar to a gel implant, but softer than a cohesive gel implant.


2012 ◽  
Vol 430-432 ◽  
pp. 828-833
Author(s):  
Qiu Sheng Ma ◽  
Yi Cai ◽  
Dong Xing Tian

In this paper, based on ANSYS the topology optimization design for high pressure storage tank was studied by the means of the finite element structural analysis and optimization. the finite element model for optimization design was established. The design variables influence factors and rules on the optimization results are summarized. according to the calculation results the optimal design result for tank is determined considering the manufacturing and processing. The calculation results show that the method is effective in optimization design and provide the basis to further design high pressure tank.


Author(s):  
Liu Ruiwei ◽  
Hongwei Guo ◽  
Zhang Qinghua ◽  
Rongqiang Liu ◽  
Tang Dewei

Balancing stiffness and weight is of substantial importance for antenna structure design. Conventional fold-rib antennas need sufficient weight to meet stiffness requirements. To address this issue, this paper proposes a new type of cable-rib tension deployable antenna that consists of six radial rib deployment mechanisms, numerous tensioned cables, and a mesh reflective surface. The primary innovation of this study is the application of numerous tensioned cables instead of metal materials to enhance the stiffness of the entire antenna while ensuring relatively less weight. Dynamic characteristics were analyzed to optimize the weight and stiffness of the antenna with the finite element model by subspace method. The first six orders of natural frequencies and corresponding vibration modes of the antenna structure are obtained. In addition, the effects of structural parameters on natural frequency are studied, and a method to improve the rigidity of the deployable antenna structure is proposed.


2014 ◽  
Vol 548-549 ◽  
pp. 383-388
Author(s):  
Zhi Wei Chen ◽  
Zhe Cui ◽  
Yi Jin Fu ◽  
Wen Ping Cui ◽  
Li Juan Dong ◽  
...  

Parametric finite element model for a commonly used telescopic boom structure of a certain type of truck-mounted crane has been established. Static analysis of the conventional design configuration was performed first. And then an optimization process has been carried out to minimize the total weight of the telescopic structures. The design variables include the geometric shape parameters of the cross-sections and the integrated structural parameters of the telescopic boom. The constraints include the maximum allowable equivalent stresses and the flexure displacements at the tip of the assembled boom structure in both the vertical direction and the circumferential direction of the rotating plane. Compared with the conventional design, the optimization design has achieved a significant weight reduction of up to 24.3%.


2009 ◽  
Vol 419-420 ◽  
pp. 89-92
Author(s):  
Zhuo Yi Yang ◽  
Yong Jie Pang ◽  
Zai Bai Qin

Cylinder shell stiffened by rings is used commonly in submersibles, and structure strength should be verified in the initial design stage considering the thickness of the shell, the number of rings, the shape of ring section and so on. Based on the statistical techniques, a strategy for optimization design of pressure hull is proposed in this paper. Its central idea is that: firstly the design variables are chosen by referring criterion for structure strength, then the samples for analysis are created in the design space; secondly finite element models corresponding to the samples are built and analyzed; thirdly the approximations of these analysis are constructed using these samples and responses obtained by finite element model; finally optimization design result is obtained using response surface model. The result shows that this method that can improve the efficiency and achieve optimal intention has valuable reference information for engineering application.


2021 ◽  
Author(s):  
Cécile Ducrocq ◽  
Halldór Geirsson ◽  
Alex Hobé ◽  
Gylfi Páll Hersir ◽  
Thóra Árnadóttir ◽  
...  

<p>Crustal deformation in volcanic areas relates ground motions, measured by geodetic techniques, to physical (e.g. pressure or volumetric) changes of magmatic sources below the surface. These measurements contribute to studies of<!-- this is not optimal, changing it might require rewriting the entire sentence. Perhaps you want to break this sentence into two. --> ongoing processes at the source of possible unrest, and are thus key for hazard assessment in active volcanic areas around the globe. However, such assessments often rely on geodetic-based models with quite simplistic assumptions of the physical structure of the volcanic complex. Particularly, constant values of elastic parameters (e.g. Poisson’s ratio and shear moduli) are commonly used for entire active volcanic areas, thus overlooking the spatial effects of lithological properties, depth-dependant compression and temperature variations on those parameters. These simplifications may lead to inaccurate interpretation of the location, shape, and volume change of deformation sources.</p><p> </p><p>In this study we ask how the 3-D heterogeneities of the elastic crustal structure beneath the Hengill volcanic system, SW Iceland, affects models of deformation sources in the area. The Hengill area hosts two active volcanic systems (Hengill and Hrómundartindur), and two high-enthalpy geothermal power plants (Nesjavellir and Hellisheiði), which provide thermal and electrical power to Reykjavík, the capital of Iceland, only 30 km away. To retrieve information on the spatial heterogeneities in the shear moduli and Poisson’s ratio beneath the Hengill area, we first estimate the 3-D shallow density structure of the area using results from regional and local gravimetric surveys. We implement this structure, along with seismic tomographic studies of the SW Iceland, in a Finite Element Model to solve, using forward models, for the 3-D heterogeneities in the shear moduli and Poisson’s ratio beneath the Hengill area.<!-- This might be more effective if the order of these statements is changed, for example: To achieve [stated goal] we produce [FEM] using [results from geophysics]. --> Furthermore, we discuss the difference between static and kinematic elastic moduli, which is important when building deformation models from seismic tomography.<!-- My first reaction to this statement is: "How do you address this?" This could be answered directly, except if you think it detracts from the story. --> The new 3-D inferred elastic model is then used to re-estimate parameters for different sources of deformation causing uplift and subsidence in the area in the past decades. This study shows the importance of accounting for heterogeneities in the crustal elastic structure to estimate with higher accuracy the sources of deformation in volcanic areas around the world.</p>


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