Comment on: “Isogeometric thermal postbuckling analysis of porous FGM quasi-3D nanoplates having cutouts with different shapes based upon surface stress elasticity” [Composite Structures 262 (2021) 113604]

2021 ◽  
pp. 114555
Author(s):  
Ashraf M. Zenkour
Keyword(s):  
Surface Stress ◽  
Composite Structures ◽  
Different Shapes ◽  
Thermal Postbuckling

scholarly journals Fixed and Base Isolated Framed Structures: A Comparative Study

2021 ◽  
Vol 2070 (1) ◽  
pp. 012198
Author(s):  
Sajan K Jose ◽  
G S Anjali ◽  
Aarya S Nair ◽  
D A Adithya ◽  
Ananya Sony ◽  
...  
Keyword(s):  
Composite Structures ◽  
Base Isolation ◽  
Response Spectrum ◽  
Structural Vibration ◽  
Structural Vibration Control ◽  
Rc Structure ◽  
Lead Rubber Bearings ◽  
Different Shapes ◽  
Control Technologies ◽  
Rubber Bearings

Abstract Necessity of constructing multi-storied buildings is increasing these days. But they are more prone to severe damage due to earthquakes. Base isolation is one of the most powerful tools pertaining to the passive structural vibration control technologies. The structure above the ground, is separated from the effects of earthquake forces by introducing a mechanism that helps the structure to hover. This project deals with analysis of 10 storey RCC, Steel and Composite structures of different shapes with and without base isolation in various seismic zones by Response Spectrum Method using ETABS software. Lead rubber bearings designed as per UBC97 was used for base isolation. Plus shape was found to be most suitable for base isolation for RC structure, whereas for steel and composite structures rectangular and hollow shapes were found suitable. It was also observed that concrete structure performs best when base isolated, compared to other structures.

scholarly journals Numerical Optimization of Stress Concentration in Composite Structures for Different Material Arrangement

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2957
Author(s):  
Sushant Bhalchandra Pate ◽  
Ryszard Korycki
Keyword(s):  
Composite Structures ◽  
Glass Fibers ◽  
Weighted Average ◽  
Composite Plates ◽  
Sandwich Composite ◽  
Stress Distributions ◽  
Complex Load ◽  
Material Characteristics ◽  
Different Shapes ◽  
Machine Parts

Complex machine parts are characterized by different shapes, material characteristics and working loads. The simultaneous theoretical optimization of shape and material properties is difficult because the single objective functional with a unique physical interpretation is unknown for these two features. The optimization is the multi-criteria procedure or the functional is a weighted average of partial criteria with the assumed weight values. Therefore, the structure and material characteristics are optimized numerically. The main goal of the article was to model and optimize the stress distribution inside the composite plates subjected to complex load. The advanced material composition was made of four different materials: steel, ductile iron, E-glass fibers and carbon fibers. The stress distributions were optimized for the homogeneous plate, the sandwich composite made of metal and textile layers, and the plate with additional stiffening elements (ribs and another plate along the neck portion). Based on the numerical simulations, the optimal structural shapes and material arrangements were determined.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Structural phenomena in the growth of carbon nanotubes

1993 ◽  
Vol 51 ◽  
pp. 750-751
Author(s):  
Jun Jiao
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Carbonaceous Material ◽  
Cluster Growth ◽  
Structural Elements ◽  
Rich Variety ◽  
Different Shapes ◽  
Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

A Numerical and Experimental Approach for Modeling Porosity Due to Entrapped Air and Volatiles Off-gassing During Manufacturing of Composite Structures

2019 ◽  
Author(s):  
Curtis Hickmott ◽  
Alireza Forghani ◽  
Victoria Hutten ◽  
Evan Lorbiecki ◽  
Frank Palmieri ◽  
...  
Keyword(s):  
Composite Structures ◽  
Experimental Approach ◽  
Entrapped Air
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