A Study on the Application of Hybrid Panels to Ship Structures

2014 ◽  
Author(s):  
Takao Yoshikawa ◽  
Yukichi Takaoka ◽  
Masahiro Maeda
Keyword(s):  
Residual Deformation ◽  
Peel Strength ◽  
Experimental Results ◽  
Liquefied Petroleum Gas ◽  
Three Point Bending ◽  
The Core ◽  
Stiffened Structures ◽  
Weak Points ◽  
The Difference ◽  
Collapse Behavior

The application of hybrid panels composed of polyurethane foam cores and steel faceplates to hull structures was studied. First, the strength and collapse behavior of the panels were examined using three-point bending tests for hybrid panels with different core densities. Based on the experimental results, low-density core materials, such as those having a density of 300 kg/m3, are recommended for hybrid panels with respect to strength and weight. The structural strength of hybrid panels was investigated through a series of calculations utilizing FEA for beams clamped at both ends under uniform pressure by changing the thickness of the faceplates and core, and the length of the clamped span. Taking account of the structural advantages of hybrid panel structures, two kinds of applications for hybrid panels are proposed. One is in the inner bottom structure of bulk carriers. There is the possibility of improving the residual strength of hybrid panels after they are subjected to severe impacts. The dynamic characteristics of hybrid panels were investigated. It was confirmed that the residual deformation of hybrid structures after impact loading is less than that of ordinary stiffened structures of the same weight. The other application is in the structural members of pressurized LPG (Liquefied Petroleum Gas) tanks. In utilizing hybrid panels in LPG tanks, the difference in rigidity between the core and skin produces a high peak bending stress in the vicinity of the clamped ends. In this paper, measures for the mitigation of this phenomenon are proposed. Also, the difference in rigidity between core and skin also produces weak points in hybrid panels such as the interface between the core and skin-plate. The applicability of hybrid panels in tank systems was examined by numerical methods utilizing the experimental results and it was confirmed that the shear and peel strength of the interface is more than sufficient.

scholarly journals Prototype of a controllable damper based on granular materials subjected to partial vacuum

2019 ◽  
Vol 254 ◽  
pp. 05009
Author(s):  
Robert Zalewski ◽  
Piotr Bartkowski
Keyword(s):  
Energy Dissipation ◽  
Granular Materials ◽  
Atmospheric Pressure ◽  
Experimental Results ◽  
Friction Forces ◽  
The Core ◽  
The Difference ◽  
Partial Vacuum

In the paper a proposal of granular damper prototype has been introduced. The granular damper works on the basis of a core made of Vacuum Packed Particles. Idea of Vacuum Packed Particles consists of placing loose granular grains into a hermetic envelope, wherein in the next stage a partial vacuum is generated. The difference between an atmospheric pressure, externally surrounding the core and internal one, causes occurring friction forces between single grains. Interacting friction forces are greater for higher values of internal underpressure. In presented paper the authors focus on analysis of experimental results obtained for various values of underpressure. Variations in energy dissipation possibilities are particularly described in this paper.

Regular Fracture Control of Pressed Notch Bar under Three-Point Bending

2008 ◽  
Vol 33-37 ◽  
pp. 61-66 ◽  
Author(s):  
Chang Feng Yan ◽  
You Tang Li ◽  
Wu Yin Jin ◽  
Li Xiao Wu ◽  
Hua Huang
Keyword(s):  
Crack Propagation ◽  
Strong Support ◽  
Experimental Results ◽  
Stress Theory ◽  
Three Point Bending ◽  
Simulation Results ◽  
Fracture Control ◽  
The Difference ◽  
Fracture Section

A new method for fabricating crack is introduced by pressing the wedge on bar. The path of the crack propagation is not regular when the ratio of length and diameter is less than 1.8 on the symmetrical support. The load of the wedge for pressing the notch is given in this paper. The 2-D finite element is applied to simulate the crack propagation by the maximum normal stress theory. The experimental results show that the quality of the fracture section will vary with the span on the three-point bending. In order to control the crack propagation along the desired section regularly, the asymmetrical three-point bending is proposed. The simulation results show that when the difference of the two spans is between 11 and 22 in asymmetrical three-point bending under the parameters condition, the good quality of the section will be obtained, and the experimental results also strong support the conclusion.

Spatial Social Choice

2019 ◽  
pp. 207-244
Author(s):  
Norman Schofield
Keyword(s):  
United States ◽  
Stochastic Model ◽  
Social Choice ◽  
Spatial Models ◽  
The United States ◽  
Multinomial Logit ◽  
Experimental Results ◽  
The Core ◽  
Voting Game ◽  
Voter Choice

A key concept of social choice is the idea of the Condorcet point or core. For example, consider a voting game with four participants so any three will win. If voters have Euclidean preferences, then the point at the center will be unbeaten. Earlier spatial models of social choice focused on deterministic voter choice. However, it is clear that voter choice is intrinsically stochastic. This chapter employs a stochastic model based on multinomial logit to examine whether parties in electoral competition tend to converge toward the electoral center or respond to activist pressure to adopt more polarized policies. The chapter discusses experimental results of the idea of the core explores empirical analyses of elections in Israel and the United States.

Static and dynamic response of sandwich beams with lattice and pantographic cores

2021 ◽  
pp. 109963622110338
Author(s):  
Yury Solyaev ◽  
Arseniy Babaytsev ◽  
Anastasia Ustenko ◽  
Andrey Ripetskiy ◽  
Alexander Volkov
Keyword(s):  
Mechanical Performance ◽  
Lattice Structure ◽  
Unit Length ◽  
Experimental Tests ◽  
Plane Geometry ◽  
Sandwich Beams ◽  
Static Tests ◽  
Three Point Bending ◽  
The Core ◽  
The Impact

Mechanical performance of 3d-printed polyamide sandwich beams with different type of the lattice cores is investigated. Four variants of the beams are considered, which differ in the type of connections between the elements in the lattice structure of the core. We consider the pantographic-type lattices formed by the two families of inclined beams placed with small offset and connected by stiff joints (variant 1), by hinges (variant 2) and made without joints (variant 3). The fourth type of the core has the standard plane geometry formed by the intersected beams lying in the same plane (variant 4). Experimental tests were performed for the localized indentation loading according to the three-point bending scheme with small span-to-thickness ratio. From the experiments we found that the plane geometry of variant 4 has the highest rigidity and the highest load bearing capacity in the static tests. However, other three variants of the pantographic-type cores (1–3) demonstrate the better performance under the impact loading. The impact strength of such structures are in 3.5–5 times higher than those one of variant 4 with almost the same mass per unit length. This result is validated by using numerical simulations and explained by the decrease of the stress concentration and the stress state triaxiality and also by the delocalization effects that arise in the pantographic-type cores.

A Novel Locality Sensitive K-Means Clustering Algorithm based on Core Clusters

2013 ◽  
Vol 321-324 ◽  
pp. 1939-1942
Author(s):  
Lei Gu
Keyword(s):  
Clustering Algorithm ◽  
Experimental Results ◽  
Clustering Method ◽  
Neighborhood Graph ◽  
The Core ◽  
Random Samples

The locality sensitive k-means clustering method has been presented recently. Although this approach can improve the clustering accuracies, it often gains the unstable clustering results because some random samples are employed for the initial centers. In this paper, an initialization method based on the core clusters is used for the locality sensitive k-means clustering. The core clusters can be formed by constructing the σ-neighborhood graph and their centers are regarded as the initial centers of the locality sensitive k-means clustering. To investigate the effectiveness of our approach, several experiments are done on three datasets. Experimental results show that our proposed method can improve the clustering performance compared to the previous locality sensitive k-means clustering.

Simulation and experimentation of a magnetorheological brake with adjustable gap

2016 ◽  
Vol 28 (12) ◽  
pp. 1614-1626 ◽  
Author(s):  
Wan-Li Song ◽  
Dong-Heng Li ◽  
Yan Tao ◽  
Na Wang ◽  
Shi-Chao Xiu
Keyword(s):  
Magnetorheological Fluid ◽  
Structure Design ◽  
Experimental Results ◽  
Wear Property ◽  
Braking Performance ◽  
Braking Torque ◽  
The Difference ◽  
The Impact ◽  
Theoretical Analyses ◽  
Magnetostatic Simulation

The aim of this work is to investigate the effect of the small magnetorheological fluid gap on the braking performance of the magnetorheological brake. In this article, theoretical analyses of the output torque are given first, and then the operating principle and design details of the magnetorheological brake whose magnetorheological fluid gap can be altered are presented and discussed. Next, the magnetic circuit of the proposed magnetorheological brake is conducted and further followed by a magnetostatic simulation of the magnetorheological brakes with different sizes of fluid gap. A prototype of the magnetorheological brake is fabricated and a series of tests are carried out to evaluate the braking performance and torque stability, as well as the verification of the simulation results. Experimental results show that the braking torque increases with the increase in the current, and the difference for the impact of the fluid gap on braking performance is huge under different currents. The rules, which the experimental results show, have an important significance on both the improvement of structure design for magnetorheological brake and the investigation of the wear property under different fluid gaps.

Spatial Convergence in Height in Central Europe, 1890-1910

2009 ◽  
pp. 90
Author(s):  
Marek Brabec ◽  
John Komlos
Keyword(s):  
Global Economy ◽  
Well Being ◽  
Habsburg Monarchy ◽  
The Core ◽  
Military Recruits ◽  
Convergence Clubs ◽  
Spatial Convergence ◽  
Physical Stature ◽  
The Difference ◽  
Peripheral Areas

We examine spatial convergence in biological well-being in the Habsburg Monarchy, circa 1890-1910, on the basis of evidence of the physical stature of 21-year-old military recruits, disaggregated into 15 Districts. We find that the shorter the population in 1890, the faster its height grew thereafter. Hence, there was convergence in physical stature between the peripheral areas of the monarchy (located in today’s Poland/Ukraine, Romania, and Slovakia) and its core (located in today’s Austria, Czech Republic, and Hungary). The difference in trends between the trend in height in the Polish District of Przemysl and in Vienna was about 0.9 cm per decade, in favor of the former. Convergence among the core Districts themselves was minimal or non-existent, whereas the convergence among the peripheral Districts was more pronounced. Spatial convergence also took place between the peripheral regions and the more developed ones. The pattern is somewhat reminiscent of modern findings on convergence clubs in the global economy.

Gebruiksaspecten van het uitroeppartikel wat in het Nederlands en Fries

2020 ◽  
Vol 136 (4) ◽  
pp. 189-209
Author(s):  
Henk Wolf
Keyword(s):  
The Core ◽  
The Difference ◽  
Lexical Phrase ◽  
High Degree ◽  
Lexical Phrases

Abstract Both Dutch and (West) Frisian make use of the exclamative particle wat (‘how’), that adds an element of surprise about a high degree of something to the semantics of the sentence. In this paper I will first show the similarities between the use of the particle in the two languages. I will demonstrate that, in Dutch, its use is largely confined to constructions that are semantically scalable, whereas in Frisian this restriction is far less strict. I will explain the difference by showing that Dutch wat is a syntactic amplifier of lexical phrases, whereas Frisian wat has developed into a pragmatic amplifier of the core predicate. I will try to account for that difference by showing how homophonous words absent in Dutch are likely to have influenced the use of Frisian wat, and how Dutch prosody strengthens the connection between wat and the amplified lexical phrase, whereas Frisian prosody weakens it. Finally, I will show that the system described as ‘Frisian’ is occasionally found in varieties of Dutch too

scholarly journals A comparative analysis of differentially expressed mRNAs, miRNAs and circRNAs provides insights into the key genes involved in the high-altitude adaptation of yaks

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Qianyun Ge ◽  
Yongbo Guo ◽  
Wangshan Zheng ◽  
Yuan Cai ◽  
Xuebin Qi ◽  
...  
Keyword(s):  
High Altitude ◽  
Molecular Mechanisms ◽  
Regulation Of Gene Expression ◽  
Differentially Expressed ◽  
The Tibetan Plateau ◽  
The Core ◽  
Processing Pathways ◽  
Genetic Information Processing ◽  
Altitude Adaptation ◽  
The Difference

Abstract Background Yaks that inhabit the Tibetan Plateau exhibit striking phenotypic and physiological differences from cattle and have adapted well to the extreme conditions on the plateau. However, the mechanisms used by these animals for the regulation of gene expression at high altitude are not fully understood. Results Here, we sequenced nine lung transcriptomes of yaks at altitudes of 3400, 4200 and 5000 m, and low-altitude Zaosheng cattle, which is a closely related species, served as controls. The analysis identified 21,764 mRNAs, 1377 circRNAs and 1209 miRNAs. By comparing yaks and cattle, 4975 mRNAs, 252 circRNAs and 75 miRNAs were identified differentially expressed. By comparing yaks at different altitudes, we identified 756 mRNAs, 64 circRNAs and 83 miRNAs that were differentially expressed (fold change ≥2 and P-value < 0.05). The pathways enriched in the mRNAs, circRNAs and miRNAs identified from the comparison of yaks and cattle were mainly associated with metabolism, including ‘glycosaminoglycan degradation’, ‘pentose and glucuronate interconversions’ and ‘flavone and flavonol biosynthesis’, and the mRNAs, circRNAs and miRNAs identified from the comparison of yaks at different altitude gradients were significantly enriched in metabolic pathways and immune and genetic information processing pathways. The core RNAs were identified from the mRNA-miRNA-circRNA networks constructed using the predominant differentially expressed RNAs. The core genes specific to the difference between yaks and cattle were associated with the endoplasmic reticulum and fat deposition, but those identified from the comparison among yaks at different altitude gradients were associated with maintenance of the normal biological functions of cells. Conclusions This study enhances our understanding of the molecular mechanisms involved in hypoxic adaptation in yaks and might contribute to improvements in the understanding and prevention of hypoxia-related diseases.

scholarly journals Territorial organization of the restaurant facilities of Kyiv agglomeration

2015 ◽  
pp. 79-82
Author(s):  
K. Dmytriieva
Keyword(s):  
Restaurant Industry ◽  
The Core ◽  
Industry Standards ◽  
The Status ◽  
Territorial Organization ◽  
The Difference ◽  
Surrounding Areas ◽  
Concentration Ratios

The article outlines the factors of development of the restaurant facilities in Kyiv and surrounding areas. The status of the territorial organization of the restaurant facilities of Kyiv and Kyiv region through the review of the main indicators of the industry by districts in 2013 has been analyzed. Comparison of the industry standards due to availability of these services to population needs has been performed. The result of the difference of efficiency of the restaurant industry through calculation of concentration ratios turnover has been received. Area that can be considered as the core of the restaurant industry of Kyiv agglomeration and area with the potential of growth has been identified. The article visualized by maps.

Sign in / Sign up

Export Citation Format

Share Document