scholarly journals Similitude Analysis on Mechanical Parameters of Thin Walled Shells

2011 ◽  
Vol 2-3 ◽  
pp. 936-941 ◽  
Author(s):  
Gao Ming Qin ◽  
Hai Yang Duan ◽  
Zhong Luo ◽  
Qing Kai Han
Keyword(s):  
Free Vibration ◽  
Scaling Laws ◽  
Natural Frequencies ◽  
Numerical Data ◽  
Fundamental Parameters ◽  
Thin Walled ◽  
Relationship Of ◽  
The Relationship ◽  
Finite Method ◽  
Walled Cylinder

The relationship of the kinetic fundamental parameters for both the prototype and model are derived by employing the finite method. Based on the relations, the scaling laws of the thin walled cylinder for the free vibration are found by applying the similitude transformation to the governing equation. In the absence of the experimental data, the validity of the scaling laws is testified by numerical data. This is done by calculating theoretically the natural frequencies for free vibration of the cylinders. By substituting the model frequencies in the scaling laws, the frequencies of the prototype are obtained. Consequently, the frequencies of the model and prototype are compared. Examples that one end of the thin walled shell is clamped and the other is simply supported show exact agreement.

Free Vibration of Thin-Walled Open Section Beams With Unconstrained Damping Treatment

1981 ◽  
Vol 48 (1) ◽  
pp. 169-173 ◽  
Author(s):  
S. Narayanan ◽  
J. P. Verma ◽  
A. K. Mallik
Keyword(s):  
Free Vibration ◽  
Cross Section ◽  
Transverse Vibration ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Numerical Results ◽  
Simply Supported ◽  
Clamped Beams ◽  
Thin Walled ◽  
Open Cross Section

Free-vibration characteristics of a thin-walled, open cross-section beam, with unconstrained damping layers at the flanges, are investigated. Both uncoupled transverse vibration and the coupled bending-torsion oscillations, of a beam of a top-hat section, are considered. Numerical results are presented for natural frequencies and modal loss factors of simply supported and clamped-clamped beams.

Combined Analysis of Pathology and Hemodynamics of Human Unruptured Cerebral Aneurysm With Thin-Walled Region

2013 ◽  
Author(s):  
Yasutaka Tobe ◽  
Takanobu Yagi ◽  
Yuki Iwabuchi ◽  
Momoko Yamanashi ◽  
Kenji Takamura ◽  
...  
Keyword(s):  
Cerebral Aneurysms ◽  
Physiological Effect ◽  
Unruptured Cerebral Aneurysm ◽  
Computational Fluid Dynamics Cfd ◽  
Thin Walled ◽  
Cfd Analyses ◽  
Relationship Of ◽  
The Relationship ◽  
Sem Analyses ◽  
Cell Thickness

Cerebral aneurysms are known as the top reason of subarachnoid hemorrhage (SAH). They are studied in the medical and the engineering field to reveal their pathogenesis, progression, and rupture mechanisms1,2. The pathological studies revealed the site of predilection, rupture rate, the risk factors1, inflammation within the aneurysm, and conditions of endothelial cells (EC) in the aneurysms3. The current pathological analyses of the cerebral aneurysms are all phenomenological and it does not consider the cause-and-effect mechanisms between the mechanical stimulation and the physiological effect although hemodynamics is thought to play an important role in the mechanisms of aneurysms. One reason that the aneurysms’ mechanisms remain unsolved is because the pathology and hemodynamics are studied independently. Purpose of this study is to reveal the relationship of endothelial cell, thickness, and hemodynamics of the cerebral aneurysms by comparing the scanning electron microscope (SEM) analyses, μCT, and the computational fluid dynamics (CFD) analyses of the cerebral aneurysms.

Experimental Research on Concrete Filled Thin-Walled Steel Tube Long Columns

2008 ◽  
Vol 400-402 ◽  
pp. 551-557 ◽  
Author(s):  
Bao Zhu Cao ◽  
Yao Chun Zhang ◽  
Yue Ming Zhao
Keyword(s):  
Experimental Research ◽  
Local Buckling ◽  
Steel Tube ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Global Buckling ◽  
Thin Walled ◽  
Relationship Of ◽  
The Relationship ◽  
Theoretical Results

Experimental research on square and octagonal concrete filled thin-walled steel tube long columns of 6 specimens in axial compression and 8 specimens in eccentric compression is undertaken. The relationship of global buckling bearing capacity of the columns and local buckling of the steel tubes is obtained. The test indicates that local buckling occurs in steel tube of each column before it reaches ultimate capacity, and has little effect on global buckling performance. The ultimate load decreases obviously with the increase of slender ratio and eccentricity. The ductility of columns increases with the increase of steel ratio in composite sections. Composite beam element of ANSYS is adopted in the finite element analysis. The theoretical results are agreed well with test..

scholarly journals The Geomorphic Evolution of the Lunar Surface

1972 ◽  
Vol 47 ◽  
pp. 43-54
Author(s):  
L. B. Ronca
Keyword(s):  
Lunar Surface ◽  
Monotonic Function ◽  
The Other ◽  
Small Scale ◽  
Fundamental Parameters ◽  
Considerable Length ◽  
Radiometric Ages ◽  
Two Parameters ◽  
Relationship Of ◽  
The Relationship

Fundamental parameters of the geomorphology of a lunar surface are (i) the number and size distribution of craters, (ii) the degree of erosion of the craters and (iii) thickness and other characteristics of the regolith. These parameters are not independent of one another; as one changes through time, the other two will also change in a statistically predictable way.In the continuous degradation sequence, the relationship between the number of craters per unit area and the degree of erosion of the craters is continuous and monotonic. This sequence occurs in areas subjected to intermediate to small impacts, and eroded mainly by the impacts themselves plus other small-scale erosional processes. In areas subjected to large impacts and mare flooding the discontinuous degradation sequence is predominant.The relationship of the first two parameters, the number of craters and the degree of erosion, with the third parameter, the regolith, is not simple and is not yet understood. It appears, however, that the geomorphological stage is more important than the mare-versus-highland dichotomy of the lunar surface.The solution of the function relating craters of the continuous degradation sequence with degree of erosion was defined as the geomorphic index of the area. Studies of the geomorphic index of stratigraphic surfaces show that areas covered by considerable ballistic sediments have a geomorphic index which is not a monotonic function of time. On the other hand, areas covered almost exclusively by mare flooding show an index which is a monotonic function of the age of the flooding. As each mare surface shows a considerable range in indices, it is concluded that maria are covered by surfaces formed through a considerable length of time. By using Apollo 11 and 12 radiometric ages it is suggested that the time of mare flooding lasted on the order of one billion (109) years.The geomorphic index of highland surfaces shows a remarkable degree of order; i.e., the farther an area is inland from the mare shores, the higher will be the index. No explanation is given to this phenomenon, but is suggested that lunar erosion is not just a localized phenomenon centered on the locus of an impact, but has lateral trends of regional dimensions. Electrostatic transportation as suggested by Gold is a possible mechanism.

scholarly journals Excitation of field line resonances by sources outside the magnetosphere

2005 ◽  
Vol 23 (10) ◽  
pp. 3375-3388 ◽  
Author(s):  
A. D. M. Walker
Keyword(s):  
Field Line ◽  
Turning Point ◽  
Natural Frequencies ◽  
Harmonic Wave ◽  
Reflection And Transmission ◽  
Field Line Resonances ◽  
Cavity Modes ◽  
Relationship Of ◽  
The Relationship ◽  
Stratified Model

Abstract. Field line resonances are thought to be excited by sources either at the magnetopause or outside it. Recent observations suggest that they may be associated with coherent oscillations or pressure pulses in the solar wind. In either case the excitation mechanism can be understood by considering the incidence of a harmonic wave on the magnetopause from outside the magnetosphere. Calculations are performed in a plane stratified model that consists of (i) a magnetosheath region streaming tailward at uniform velocity (ii) a sharp boundary representing the magnetopause, (iii) a magnetosphere region in which the Alfvén speed increases monotonically with distance from the magnetopause. The structure implies the existence of a propagating region within the magnetopause bounded by a reflection level or turning point. Beyond this is a region in which waves are evanescent and a resonance level. The reflection and transmission of harmonic waves incident from the magnetosheath is considered in this model. It is shown that, in most cases, because of the mismatch between the magnetosphere and the magnetopause, the wave is reflected from the magnetopause with little penetration. At critical frequencies corresponding to the natural frequencies of the cavity formed between the magnetopause and turning point the signal excites the cavity and may leak evanescently to the resonance. The calculation includes the effect of the counter-streaming magnetosheath and magnetosphere plasmas on the wave. This can lead to amplification or attenuation. The nature of the processes that lead to transmission of the wave from magnetosheath to resonance are considered by synthesising the signal from plane wave spectra. A number of mechanisms for exciting cavity modes are reviewed and the relationship of the calculations to these mechanisms are discussed. Observations needed to discriminate between the mechanisms are specified.

scholarly journals RELATIONSHIP OF PARENTING TO TEMPER TANTRUM BEHAVIOR OF CHILDREN 3-5 YEARS OLD IN PAUD MAWAR FKIP UNPATTI

2020 ◽  
Vol 1 (1) ◽  
pp. 44-51
Author(s):  
Hermelina Abarua
Keyword(s):  
Numerical Data ◽  
Department Of Education ◽  
Preschool Age ◽  
Education Faculty ◽  
Chi Square ◽  
Training And Education ◽  
Temper Tantrum ◽  
Relationship Of ◽  
The Relationship ◽  
Temper Tantrums

2019 "The Relationship of Parenting to Temper Tantrum Behavior Children 3-5 Years Old in PAUD Mawar FKIP Unpatti" Department of Education Faculty of Teacher Training and Education Faculty of Pattimura University Ambon. Tantrums (or temper tantrums) are emotional outbursts, usually associated with children or people in emotional distress, which are usually characterized by stubbornness, crying, screaming, screaming, screaming, insubordination, ranting angry, angry, resistance to efforts to calm and, in some cases, violence. Physical control can be lost, the person may not be able to remain silent, and even if the person's "goals" are fulfilled he may remain uneasy. This research was carried out at PAUD Mawar FKIP Unpatti. The purpose of the study was to determine the relationship of parenting to the incidence of temper tantrums in children aged 3-5 years in PAUD Mawar Unpatti. Research using a quantitative approach emphasizes its analysis on numerical data that is processed by statistical methods. The results of the analysis using the Chi Square statistical test with the SPSS program version 16.0 obtained ρ = 0.001 <α = 0.05 with a pearson count = 15.069 then H1 accepted H0 was rejected, which means there is a relationship between parenting parents with temper tantrums in preschool age children (3-5 Years) in Mawar PAUD FKIP Unpatti with a correlation of 0.501 which is interpreted that the strength of the relationship between variables is at a moderate level. 31 respondents in PAUD Mawar FKIP Unpatti showed that parenting in the Poor category was 10 respondents (32.46%) and 21 respondents (67.74%) had good parenting. Data of 31 respondents in PAUD Mawar FKIP Unpatti showed 15 respondents (48.38%) showed high temper tantrums, 10 respondents (32.25%) showed moderate temper tantrums, and 6 respondents (19.35%) showed low temper tantrums.

A New Static Analysis Approach for Free Vibration of Beams

2018 ◽  
Vol 10 (01) ◽  
pp. 1850004 ◽  
Author(s):  
C. W. Lim ◽  
Zhenyu Chen
Keyword(s):  
Free Vibration ◽  
Static Analysis ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Numerical Solutions ◽  
Free Vibration Analysis ◽  
Concentrated Force ◽  
Static Approach ◽  
Beam Bending ◽  
The Relationship

This study deals with a new method for the free vibration analysis of beams under different boundary conditions. We show that it is possible to apply a static approach for solving free vibration systems, i.e., we obtain natural frequencies for free vibration of beams by analyzing static beam bending problems. Specifically, the basic governing equation for beams with harmonic loadings and resting on an elastic foundation is solved and the solutions are used directly to yield the beam free vibration solutions. In the free vibration analysis, the natural frequency can be a real number or an imaginary number while in the static analysis, the foundation stiffness can be either positive or negative. We show that one can solve the deflection of a beam subjected to a given concentrated force and subsequently deduce the possible infinite deflection when the stiffness becomes zero or negative. In such cases, there exists an equivalent relationship between the free vibration frequencies and the negative stiffness. Consequently, determining the natural frequencies becomes a problem of determining an appropriate negative foundation elastic constant. In general, the numerical vibration solutions can be obtained by analyzing the relationship between loadings and frequencies. For comparison, a comparison with the classical free vibration solutions is presented and excellent agreement is illustrated. We further show that this static approach for free vibration solutions has a clear edge over the classical free vibration approach in computational beam vibration solutions. Very accurate and convergent numerical solutions can be obtained using a very simple numerical solution method. This static approach for free vibration problems can be extended for plate, shell and other structural systems.

Investigation of the numerical, experimental, statistical and optimization of thin-walled energy absorber with novel configuration using response surface method under axial loading

2018 ◽  
Vol 22 (8) ◽  
pp. 2735-2767
Author(s):  
Ali Bigdeli ◽  
Mohammad Damghani Nouri
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Unit Mass ◽  
Specific Energy Absorption ◽  
Surface Method ◽  
Crushing Force ◽  
Thin Walled ◽  
Relationship Of ◽  
Walled Cylinder ◽  
Initial Peak

In this study, aluminum thin-walled cylindrical absorbers for crashworthiness are investigated to introduce a novel system with better energy absorption and crushing characteristics under quasi-static axial compressive loading. The inside of the thin-walled cylinders is meshed with a square welded from vertices to the thin-walled cylinder. Here, the response surface method, which is one of the design of experiments techniques has been used to examine the effect of the parameters on energy absorption, initial peak crushing force, specific energy absorption per unit mass and energy absorption per length. The variables of thickness (t), height (h) and length of square (l) of the thin-walled cylinder were considered in three levels and initial peak crushing force, specific energy absorption per unit mass and energy absorption per length were selected as response. The specimens were analyzed under a quasi-static compressive test at a constant speed of 10 mm/min. Subsequently, for further investigation, the experimental results were compared with those obtained from the finite element simulation using Abaqus software, which indicated desirable accuracy. To decrease the solution time in this numerical analysis, the speed was set at 0.5 m/s. Finally, the experimental results were compared with the simulation ones, which showed acceptable compatibility. Further, there are the equations obtained from the multi-objective optimization testing design. The results indicated a linear relationship of thickness with responses, nonlinear relationship of height with responses, linear relationship of length of square with initial peak crushing force, and nonlinear relationship with specific energy absorption per unit mass and energy absorption per length.

scholarly journals The Effect of Audio Visual Graphics in Perwali Implementation No 15 of 2016 on the Effectiveness of the Service Grant Recipients (Bansos) in the City of Bogor

2020 ◽  
Vol 17 (2) ◽  
pp. 204-219
Author(s):  
Heri Susanto ◽  
Abdul Muis Miraza
Keyword(s):  
Local Government ◽  
Numerical Data ◽  
Exploratory Research ◽  
Government Programs ◽  
Regression Methods ◽  
Visual Graphic ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship ◽  
The City

Effective in the service is part of the duties of the State Civil Apparatus (ASN) relating to the relationship of output responsibility with the goals to be achieved. The greater the output produced from the target to be achieved, it can be said to be effective. One of the efforts to improve services by Staf Kesra dane Kemasyarakatan Setda Kota Bogor is by using the Audio Visual Graphic (AVG). The impact of improving services will provide motivation for other employees in the local government to do work more effectively and assist in the implementation of other local government programs. This research uses a quantitative approach emphasizing its analysis on numerical data (numbers) which are processed, while the type of research used is descriptive and exploratory research, that is the type of research used based on its function, then by statistical methods multiple linear regression methods note that partially Audio Visual Graphic (as variable X) which includes educational elements (X1), social (X2), economical (X3) and culture (X4), use of Audio Visual Graphic in the implementation of guardian No. 15 of 2016 only economic elements that affect the effectiveness of the service recipient of grants/social assistance at the district of Bogor, which is equal to 0.321.

Parametric Design Study About Seismic Isolation System for Fast Reactor JSFR

2015 ◽  
Author(s):  
Nobuchika Kawasaki ◽  
Tomohiko Yamamoto ◽  
Tsuyoshi Fukasawa ◽  
Shigeki Okamura
Keyword(s):  
Natural Frequency ◽  
Seismic Isolation ◽  
Natural Frequencies ◽  
Parametric Design ◽  
Acceleration Response ◽  
Isolation System ◽  
Expansion Characteristic ◽  
Main Component ◽  
Relationship Of ◽  
The Relationship

Japanese seismic conditions are getting severer and natural frequencies of components are getting lower due to the enlargements of components’ size, therefore response accelerations and buckling margins of reactor vessels were parametrically surveyed with attention to thicknesses, diameters, and isolation frequencies for reviewing necessary isolation specification. For the first, Japanese seismic condition and present specification of JSFR isolation system are introduced in this paper. RV installed floor responses were calculated based on this seismic condition and the relationship of natural frequencies, initiated stresses, and buckling margins against vessel thicknesses and diameters were shown with trend. Expansion characteristic of isolation system was evaluated by parametric acceleration response analyses. Comparing the response of isolation system with 8Hz vertical natural frequency with other natural frequency’s isolation, response ratios against natural frequencies were calculated. Japanese seismic design condition may become severer than present one, and a natural frequency of main component may decrease. However based on the buckling margin with present plant specifications and the expansion characteristic of isolation system, the advanced isolation system with 8Hz vertical natural frequency was selected as the isolation system of JSFR at still present occasion.

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