Elastic Instability of a Stringer on Thin Sheets

1962 ◽  
Vol 66 (620) ◽  
pp. 530-531
Author(s):  
J. B. Caldwell
Keyword(s):  
Structural Design ◽  
Diffusion Problem ◽  
The Other ◽  
Elastic Instability ◽  
Thin Sheets ◽  
Aircraft Structures

Figure 1 illustrates a load diffusion problem which occurs in ship structural design, and which may also be relevant to aircraft structures. A load applied to one end of a stringer is diffused into the attached sheet and eventually reacted by shearing forces at the longitudinal edges. The transverse edges of the sheet and the other end of the stringer are not loaded.Various methods, which differ in their assumptions regarding stresses and displacements in the sheet, are available for tackling this problem. For calculating the distribution of load or stress in the stringer it makes little difference which method is used. The “finite stringer” method of reference (1) is the simplest and should be sufficiently accurate for most cases.

Study on Wear-Preventing of Needle Valve in Fuel Injection System Mounted on DME Engine

2011 ◽  
Vol 228-229 ◽  
pp. 1057-1062
Author(s):  
Xin Rong Wen ◽  
Guang De Zhang ◽  
Wei Hua Wang ◽  
Xie Lu ◽  
Sun Jing
Keyword(s):  
Dynamic Stability ◽  
Structural Design ◽  
Fuel Injection ◽  
Dynamic Instability ◽  
Calculation Model ◽  
The Other ◽  
Injection System ◽  
Needle Valve ◽  
Fuel Injection System ◽  
Theoretical Support

The purpose of this paper is to provide theoretical support for the structural design to prevent the wear of needle. The actual wear of the orientation part of the needle in scrapped needles was researched. The presented results showed that the main reason to the wear of the orientation part of needle was the dynamic instability and the abrasives enter into the surface of orientation part which increases the wear, and that the calculation model of dynamic stability was proposed to prevent the wear of needle. This model was a pressure rod, one end of which was fixed, the other was free, and the two ends were pressed on axial force which changes with time. Besides, the classic formula of dynamic stability of pressure rod was changed rationally, so as to correspond with the calculation model. It will play a part in preventing the wear of needle.

MEASUREMENT OF SURFACE STRESS: DESCRIPTION OF AN INTERFEROMETRIC METHOD

1997 ◽  
Vol 04 (05) ◽  
pp. 1047-1050 ◽  
Author(s):  
G. DEGAND ◽  
P. MÜLLER ◽  
R. KERN
Keyword(s):  
Experimental Method ◽  
Silicon Substrate ◽  
Surface Stress ◽  
Young Modulus ◽  
Stress Change ◽  
The Other ◽  
Thin Sheets ◽  
Interferometric Method ◽  
Michelson Interferometry ◽  
Substrate Sample

In a recent publication, we proposed a new experimental method for measuring the absolute surface stress of a thin crystalline sheet based on the deformation of very thin sheets (thickness e<10 μm) submitted to disymmetrical surface stresses (S1 on one side of the sheet, S2 on the other). This paper demonstrates that Michelson interferometry can be used to measure a surface stress change of 2–3 10-3 J·m -2 if the thickness and the Young modulus of the sheet are accurately known. Using a silicon substrate sample we found that one fourth of a monolayer of silver reduces the surface stress by 0.45 J·m -2.

EERI Distinguished Lecture 1997 Professional Commitments to Earthquake Engineering

1998 ◽  
Vol 14 (4) ◽  
pp. 651-657
Author(s):  
Thomas Paulay
Keyword(s):  
Seismic Design ◽  
Earthquake Engineering ◽  
Structural Design ◽  
Design Strategy ◽  
The Other ◽  
High Quality ◽  
Generous Support ◽  
The One ◽  
Creative Effort ◽  
Quality Construction

Philosophical concepts, biased toward structural design in seismic regions, are offered. Certain misconceptions in the aims, planning and execution of structural design are sketched. Apparent diverging professional interests, motivating on the one hand young academics dedicated to pursuing challenges in research, and on the other hand those of experienced practitioners, are contrasted. A plea is made to use in seismic design rationality and simplicity in application. The primary aim in the art of structural design should be to impart to the system specific properties that will make the seismic response of our buildings extremely tolerant with respect to earthquake-induced demands, which presently we can predict only with considerable crudeness. A postulated rational and deterministic, yet simple, design strategy should be implemented with equal dedication to high-quality construction. This part of the creative effort is likely to result in properties of the finished product, our buildings, which earthquakes will also recognize and respect. An appeal is made to all those committed to earthquake engineering to engage in active and generous support of technology transfer in an attempt to alleviate the overwhelming and immediate needs of societies in developing countries.

Parametric Study on the Fluid Elastic Instability Factor of the Fuel Rod for a PWR Plant

2010 ◽  
Author(s):  
Hyeong Koo Kim ◽  
Sang Youn Jeon ◽  
Kyou Seok Lee ◽  
Jeong Ha Kim ◽  
Sang Jong Lee
Keyword(s):  
Parametric Study ◽  
The Other ◽  
Design Parameters ◽  
Elastic Instability ◽  
Direct Relation ◽  
Spacer Grid ◽  
Fuel Rod ◽  
Flow Mixing ◽  
Fuel Design ◽  
Instability Factor

The main objective of this study is to estimate the effects of some considerable fuel design parameters on the fluid elastic instability behavior of the fuel rod. For the estimation, 6 fuel design parameters which seem to have direct relation with fluid elastic instability behavior of the fuel rod have been selected and examined using the PLUS7 fuel rod for OPR1000 PWR plants in Korea. Those are fuel rod creep-down, spacer grid stiffness, spacer grid spring relaxation, inactive spacer grid spring, intermediate flow mixing grid effect and fuel rod damping. As a result, the fluid elastic instability factors are insensitive with spacer grid stiffness, relaxation and intermediate flow mixing grid effect, but the other parameters need to be controlled and evaluated appropriately to maintain stability with proper margins.

Structural Design and Analysis of the Motionlink in the Dynamic Assembled Screw-Driven Device

2013 ◽  
Vol 376 ◽  
pp. 390-394
Author(s):  
Yi Fei Feng ◽  
Xiao Jun Xu ◽  
Hai Jun Xu ◽  
Xiang Zhang ◽  
Fa Liang Zhou ◽  
...  
Keyword(s):  
Mechanical Characteristic ◽  
Structural Design ◽  
Simulation Analysis ◽  
The Other ◽  
The Right

The dynamic assembled screw-driven device is a new kind of mechanical driving device, one of its main structures is the reasonable designed motionlink. To setup two groups of oriented wheels which complied the Archimedes screw around the center cylinder, the top groups of wheels ensure the helical plates moving in the right direction otherwise be twisted, and the other groups of wheels provide the power that ensure the helical plates meshed accurately and driving stably. This paper is to calculate the structure in theory and make some primary simulation analysis for the mechanical characteristic in Static.

A New MAR-PM Image Filtering Algorithm

2014 ◽  
Vol 962-965 ◽  
pp. 2774-2777
Author(s):  
Wei Jiang ◽  
Ke Li
Keyword(s):  
Image Filtering ◽  
Diffusion Problem ◽  
The Other ◽  
Filtering Algorithm ◽  
Multi Scale ◽  
Forecast Result ◽  
Auto Regressive ◽  
Better Than

In order to solve the over-diffusion problem that often appeared in traditional PM filtering algorithm, a new PM model combined with multi-scale auto regressive (MAR) is proposed in the paper. Firstly, a series of multi-scale images can be got by MAR .Then all these images are filtered by traditional PM model and got a forecast distinct image. With this forecast result to readjust the coefficients of the PM model, the original images can be well filtered finally. The PSNR value is used to judge the efficiency, which shows the efficiency of the proposed new algorithm is much better than the other methods.

A Multiobjective Optimization Strategy with Priority Ranking of the Design Objectives

1993 ◽  
Vol 115 (4) ◽  
pp. 784-792 ◽  
Author(s):  
M. Matsumoto ◽  
J. Abe ◽  
M. Yoshimura
Keyword(s):  
Structural Design ◽  
Torsional Rigidity ◽  
The Other ◽  
Optimization Strategy ◽  
Design Requirement ◽  
Response Level ◽  
Lower Priority ◽  
Priority Ranking ◽  
Priority Order ◽  
Motorcycle Frame

Generally, two types of priorities are considered among multiple objectives in the design of machine structures. One of these objectives is named the “hard objective” and is the absolutely indispensable design requirement while the other is called “soft objective” and has a lower priority order. This paper proposes a multiobjective structural optimization strategy with priority ranking of the design objectives. Further, this strategy is demonstrated on the actual example of a motorcycle frame structural design which has three design objectives: (1) an increase in static torsional rigidity, (2) a reduction of dynamic response level, and (3) a decrease in the weight of the motorcycle frame.

scholarly journals Structural Investigation of the Synthesized Few-Layer Graphene from Coal under Microwave

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 57
Author(s):  
Faridul Islam ◽  
Arash Tahmasebi ◽  
Behdad Moghtaderi ◽  
Jianglong Yu
Keyword(s):  
Potassium Hydroxide ◽  
Bituminous Coal ◽  
Structural Investigation ◽  
The Other ◽  
Activation Process ◽  
Thin Sheets ◽  
Layer Graphene ◽  
Wide Range ◽  
Few Layer Graphene ◽  
Microwave Heat

This study focused on the structural investigation of few-layer graphene (FLG) synthesis from bituminous coal through a catalytic process under microwave heat treatment (MW). The produced FLG has been examined by Raman spectroscopy, XRD, TEM, and AFM. Coal was activated using the potassium hydroxide activation process. The FLG synthesis processing duration was much faster requiring only 20 min under the microwave radiation. To analyse few-layer graphene samples, we considered the three bands, i.e., D, G, and 2D, of Raman spectra. At 1300 °C, the P10% Fe sample resulted in fewer defects than the other catalyst percentages sample. The catalyst percentages affected the structural change of the FLG composite materials. In addition, the Raman mapping showed that the catalyst loaded sample was homogeneously distributed and indicated a few-layer graphene sheet. In addition, the AFM technique measured the FLG thickness around 4.5 nm. Furthermore, the HRTEM images of the P10% Fe sample contained a unique morphology with 2–7 graphitic layers of graphene thin sheets. This research reported the structural revolution with latent feasibility of FLG synthesis from bituminous coal in a wide range.

scholarly journals Symbols of the songs by Leela Benare in Vijay Tendulkar’s play Silence! The court is in session

2021 ◽  
Vol 9 (7) ◽  
pp. 77-84
Author(s):  
Ramen Goswami Sirjii
Keyword(s):  
Structural Design ◽  
The Other ◽  
Psychic Life ◽  
Mock Trial ◽  
Independent Life ◽  
The Right

The current study explores and sheds light on the trials and tribulations of an independent Women, Miss. Leela Benare, in Vijay Tendulkar’s play Silence! The Court is in session. Here Tendulkar dwells on gender Discriminations. Till the commencement of the mock- trial, Benare is the most cheerful, talkative Character. She makes comments on her own independent life, on the behaviour of her fellow actors, she Sings and shows her vitality and assertiveness even in the second act when the mock trial with her as the Accused begins. In this context her songs are relevant to the structural design of the play as well as these Highlight the mental agony and pangs of a deep rooted mother. In Silence! The Court is in Session, though the dialogues of the characters are set in unvarnished prosaic terms, four songs and one poem have been used in order to add lyrical flavour to unvarnished language of reality. Tendulkar has these songs sung by Benare, the protagonist of the play, not by other characters. A song is no doubt a lyric that expresses a set of emotion, feeling and ideas and thereby exposes the psychic life of the speaker. The four songs in the play, of which two are derivative and the other two are composed by the dramatist, are set in Benare’s mouth in order to equip the woman with the right to narrate her life in lyrical terms.

Development of System Based Code: Case Study of Life-Cycle Margin Evaluation

2006 ◽  
Author(s):  
Tai Asayama ◽  
Masaki Morishita ◽  
Masanori Tashimo
Keyword(s):  
Life Cycle ◽  
Structural Design ◽  
Nuclear Power ◽  
The Other ◽  
Professor Emeritus ◽  
Crucial Importance ◽  
Late Professor ◽  
Key Concepts ◽  
Plant Components

For a leap of progress in structural deign of nuclear plant components, The late Professor Emeritus Yasuhide Asada proposed the System Based Code. The key concepts of the System Based Code are; (1) life-cycle margin optimization, (2) expansion of technical options as well as combinations of technical options beyond the current codes and standards, and (3) designing to clearly defined target reliabilities. Those concepts are very new to most of the nuclear power plant designers who are naturally obliged to design to current codes and standards; the application of the concepts of the System Based Code to design will lead to entire change of practices that designers have long been accustomed to. On the other hand, experienced designers are supposed to have expertise that can support and accelerate the development of the System Based Code. Therefore, interfacing with experienced designers is of crucial importance for the development of the System Based Code. The authors conducted a survey on the acceptability of the System Based Code concept. The results were analyzed from the possibility of improving structural design both in terms of reliability and cost effectiveness by the introduction of the System Based Code concept. It was concluded that the System Based Code is beneficial for those purposes. Also described is the expertise elicited from the results of the survey that can be reflected to the development of the System Based Code.

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