Natural vibration of the beam-strip fabricated from a composite material with small-scale curvings in the structure

1996 ◽  
Vol 32 (4) ◽  
pp. 346-354 ◽  
Author(s):  
Z. Kütüg
2017 ◽  
Vol 742 ◽  
pp. 689-696 ◽  
Author(s):  
Larissa Born ◽  
Axel Körner ◽  
Gundula Schieber ◽  
Anna S. Westermeier ◽  
Simon Poppinga ◽  
...  

This paper presents results of the investigation of two biological role models, the shield bug (Graphosomaitalicum) and the carnivorous Waterwheel plant (Aldrovandavesiculosa). The aim was to identify biological construction and movement principles as inspiration for technical, deployable systems. The subsequent processes of abstraction and simulation of the movement and the design principles are summarized, followed by results on the mechanical investigations on various combinations of fibers and matrices with regard to taking advantage of the anisotropy of fiber-reinforced plastics (FRPs). With the results gained, it was possible to implement defined flexible bending zones in stiff composite components using one composite material, and thereby to mimic the biological role models. First small-scale demonstrators for adaptive façade shading systems – Flectofold and Flexagon – are proving the functionality.


2014 ◽  
Author(s):  
Zh. Kang ◽  
Yunhe Zhai ◽  
Ruxin Song ◽  
Liping Sun

In this paper, model tests were carried out to investigate two degrees of freedom VIV of horizontally-laid cylinders with diameters of 5cm, 11cm, 20cm and length 120cm and compared their vibration trajectories. The test results showed that the in-line and cross-flow vibration frequency of different scale cylinders demonstrate “multi frequency” phenomenon, that is, the in-line vibration frequency is not only twice but also once or four times as much as the cross-flow vibration frequency in some scale, natural frequency and reduced velocity conditions. Also, the cross-flow multi-frequency vibration phenomenon occurred. The trajectory of the vibration cylinder differentiated from the traditional “8” shape accordingly. The vibration trajectory, especially of small-scale cylinder, changed in most conspicuous manner. Through the initial research and analysis, it was found that in addition to in-line and cross-flow natural vibration frequency and the flow velocity, the shape of cylinders was also one of the main causes leading to different vibration trajectory forms.


2010 ◽  
Vol 146-147 ◽  
pp. 1583-1586 ◽  
Author(s):  
Cui Yu Li ◽  
Xiao Tao Zhang

In order to improve the computing precision and computing efficiency of strength of woven composite material, the strength of woven composite material based on multi-scale finite element method (MsFEM) is simulated. The periodical boundary conditions are applied to the finite element method analyses to ensure stress continuous and strain continuous on boundary surfaces. The method can efficiently capture the large scale behavior of the solution without resolving all the small scale features by constructing the multi-scale finite element base functions that are adaptive to the local property of the differential operator. The characteristic difference between MsFEM and the conventional finite element method is attributed to base function. The applications demonstrate that the advantages of the multi-scale finite element method for numerical simulation of strength problem of woven composite material, i.e. significantly reducing computational efforts, and improving the accuracy of the solutions.


In this examination, common strands like Abaca, Coir and Flax , Abaca and Coir (half breed) , Flax and Coir (cross breed) and Flax and Abaca (crossover) are manufactured with bio epoxy tar utilizing forming technique. In this paper the ideal blending of fortitude and sap is accomplished by utilizing Taguchi strategy. In this effort, flexural unbending nature and rigidity of Abaca besides Coir (half and half), Flax and Coir (hybridand Flax and Abaca (cross breed) composite at dry and wet conditions were considered. Hardness test remained directed utilizing rigidity testing machine. In this effort small scale edifice of the examples are examined by the Skim through Electron Hand-held microscope.


2019 ◽  
Vol 42 ◽  
Author(s):  
William Buckner ◽  
Luke Glowacki

Abstract De Dreu and Gross predict that attackers will have more difficulty winning conflicts than defenders. As their analysis is presumed to capture the dynamics of decentralized conflict, we consider how their framework compares with ethnographic evidence from small-scale societies, as well as chimpanzee patterns of intergroup conflict. In these contexts, attackers have significantly more success in conflict than predicted by De Dreu and Gross's model. We discuss the possible reasons for this disparity.


2000 ◽  
Vol 179 ◽  
pp. 403-406
Author(s):  
M. Karovska ◽  
B. Wood ◽  
J. Chen ◽  
J. Cook ◽  
R. Howard

AbstractWe applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.


Author(s):  
E. Sukedai ◽  
H. Mabuchi ◽  
H. Hashimoto ◽  
Y. Nakayama

In order to improve the mechanical properties of an intermetal1ic compound TiAl, a composite material of TiAl involving a second phase Ti2AIN was prepared by a new combustion reaction method. It is found that Ti2AIN (hexagonal structure) is a rod shape as shown in Fig.1 and its side surface is almost parallel to the basal plane, and this composite material has distinguished strength at elevated temperature and considerable toughness at room temperature comparing with TiAl single phase material. Since the property of the interface of composite materials has strong influences to their mechanical properties, the structure of the interface of intermetallic compound and nitride on the areas corresponding to 2, 3 and 4 as shown in Fig.1 was investigated using high resolution electron microscopy and image processing.


Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.


Sign in / Sign up

Export Citation Format

Share Document