scholarly journals Numerical Analysis Of Flat Slabs With Spherical Voids Subjected To Shear Force

2015 ◽  
Vol 5 (1) ◽  
pp. 7-13 ◽  
Author(s):  
M. Bindea ◽  
Claudia Maria Chezan ◽  
A. Puskas
Keyword(s):  
Shear Force ◽  
Standard Condition ◽  
Reinforcement Rate ◽  
Design Stage ◽  
Classical Solutions ◽  
Flat Slabs ◽  
Design Software ◽  
Spherical Voids ◽  
The Unemployed ◽  
Core Part

Abstract Full flat slabs can be enhanced by using spherical voids to replace the unemployed concrete from the core part of the slab. Therefore we get low self-weighted slabs that can reach a high range of spans, a low material consumption compared to classical solutions used so far. On the other hand, the upsides of these slabs pale against the insecurity in design stage about their punching and shear force behaviour. In this paper it is presented a parametric study about shear force behaviour of flat slabs with spherical voids used in standard condition service. The study was made using the Atena 3D finit element design software, starting form a numerical model gauged on experimental results on real models – scale 1:1. Based on these lab results, the model’s validation was made by overlapping the load – displacement experimental curves on the curves yielded from numerical analyses. The results indicate that under a longitudinal reinforcement rate of lower than 0.50%, flat slabs with spherical voids don’t fail to shear force and over this value the capable shear force decreases in comparison with solid slabs, as the reinforcement rate increases.

An Exploration on the Innovation Methods of the Printing and Packaging Machinery Based on Simulation

2013 ◽  
Vol 401-403 ◽  
pp. 26-30
Author(s):  
Bo Gao ◽  
Xiao Gui Zhang ◽  
Ji Fei Cai
Keyword(s):  
Design Method ◽  
Basic Mechanism ◽  
Three Dimensions ◽  
Design Stage ◽  
Kinematics And Dynamics ◽  
Interference Detection ◽  
Matlab Simulation ◽  
Packaging Machine ◽  
Complex Technology ◽  
Design Software

Printing and packaging machinery have complex technology motion. The mechanism is composed of different basic mechanism. The mechanism design is an important stage in Innovation Design of Printing and Packaging Machine. The mechanics design applying Solideworks three dimensions design software and Matlab Simulation was introduced; in the design stage, assemble interference and interference detection of the mechanics were made by Solideworks Visible model; on the basis, the analysis on the kinematics and dynamics of machinery by Matlab Simulation were done. The application example shows the Solideworks three dimensions design and Matlab Simulation is a perfect design method.

scholarly journals Study on reliability of punching shear of flat slabs without shear reinforcement according to NBR6118

2017 ◽  
Vol 10 (2) ◽  
pp. 276-297
Author(s):  
M. L. CARVALHO ◽  
C. R. SILVA ◽  
F. R. STUCCHI
Keyword(s):  
Probabilistic Model ◽  
Reliability Index ◽  
Shear Force ◽  
Limit State ◽  
Punching Shear ◽  
Slab Thickness ◽  
Ultimate Limit State ◽  
Flat Slabs ◽  
Frequent Use ◽  
Ultimate Limit

Abstract The frequent use of flat slabs in building constructions highlights the importance of improving the study of slab-column joints, particularly regarding the verification of the ultimate limit state of punching shear, given the complexity of this phenomenon. This article applies concepts of the Theory of Reliability in order to evaluate the safety of the formulation established by NBR6118: 2014 standard to check punching shear in flat slabs with centered columns. Twelve probabilistic model analysis for C and C' equations were developed, considering the influence that the variation of the slab thickness, the ������ and the shear force eccentricity have on reliability index �� and failure rate ����. Results indicated that formulation of C boundary is reasonably safe, although C'boundary revealed �� index below expectations.

scholarly journals The modernization of public spaces in problematic residential areas exemplified on selected projects and realizations in the Bronowice district of Lublin

1970 ◽  
Vol 14 (1) ◽  
pp. 89-97
Author(s):  
Kamila Boguszewska ◽  
Natalia Przesmycka
Keyword(s):  
World War Ii ◽  
Public Space ◽  
Public Spaces ◽  
Design Stage ◽  
Residential Areas ◽  
Process Implementation ◽  
Processing Plants ◽  
Real Estate Prices ◽  
The Unemployed ◽  
Housing Estates

Tatary and Bronowice are considered to be the most dangerous and problematic districts of Lublin. The problems are exacerbated by the changing age structure of the residents – “ageing” and a high percentage of the unemployed, caused by the collapse of industry in Lublin after 1989 (URSUS), which was the main sector of employment for the residents of these districts. Apart from the problems typical for all housing estates from the communist era, e.g. lack of parking spaces, there is vandalism, alcoholism and low material status of the residents. The development of the Tatary district after World War II was connected with the industrial district (among industrial plants, the biggest employer was the Fabryka Samochodów Ciężarowych (Heavy Goods Vehicle Factory) established in 1951, there was a slaughterhouse, and now – meat processing plants. Housing estates built within the Tatary district in 1950−1972 (ZOR Tatary and Motor) and Bronowice (ZOR Bronowice I 1954−1956 and Bronowice II and III 1956−1969) were characterised by a large share of green and recreational areas dedicated to various users. After several decades of lack of investment and with changing lifestyles and users’ needs, these spaces are among the most neglected in Lublin. Currently works related to the improvement of infrastructure in these housing estates are being undertaken such as: replacement of street lights, sidewalks, etc. District councils are working intensively to raise funds for the most urgent needs, but they are not always well thought out or designed in an appropriate way. The problem is the lack of models and often duplication of functional and aesthetic schemes, not always appropriate to the area. The modernization of public spaces is one of the elements of revitalisation processes, in which the involvement of future users at the design stage is a necessary element. Good public spaces increase the sense of security, comfort of living and even contribute to the increase in real estate prices. This paper presents the problems posed by the design process, implementation and functioning of selected public spaces in Tatary and Bronowice districts of Lublin where community participation played a crucial role. The article presents issues related to the design, implementation and functioning of selected public spaces in the Bronowice district, where social participation was an important factor. Challenges of public space modernization in problematic residential areas are exemplified on selected projects and realizations in the Bronowice district of the city of Lublin.

Research of Oracle Database Performance Optimization in University Educational Management System Based on Information Technology

2014 ◽  
Vol 1023 ◽  
pp. 233-236
Author(s):  
Yun Wu ◽  
Zhi Xiong Zhang ◽  
Wen Li Zhang
Keyword(s):  
Information Technology ◽  
Performance Optimization ◽  
Management System ◽  
Design Stage ◽  
Digital Campus ◽  
Educational Management ◽  
Oracle Database ◽  
The Core ◽  
Database Performance ◽  
Core Part

University educational management system is the core part of digital campus, this paper uses Oracle 11g database to study the educational management system, Oracle database performance directly impacts on the performance of management system, so the Oracle performance optimization is more and more attention to, the database performance optimization begins from the database design stage, through the database deployment stage and SQL realize process's optimization, to realize university educational management system Oracle database performance optimization goals.

scholarly journals Punching shear in reinforced concrete flat slabs with hole adjacent to the column and moment transfer

2014 ◽  
Vol 7 (3) ◽  
pp. 414-467 ◽  
Author(s):  
D. C. Oliveira ◽  
R. B. Gomes ◽  
G. S. Melo
Keyword(s):  
Reinforced Concrete ◽  
Reinforcement Rate ◽  
Load Test ◽  
Punching Shear ◽  
Test Results ◽  
Flat Slab ◽  
Flat Slabs ◽  
Flexural Reinforcement ◽  
Hole Dimension ◽  
The Moment

The structural behavior and the ultimate punching shear resistance of internal reinforced concrete flat slab-column connections, with one hole adjacent to the column, with or without flexural moment transfer of the slab to the column was investigated. Main variables were: the existence whether or not hole, flexural reinforcement layout and ratio, the direction and sense of the moment transferred and the eccentricity of the load (M (moment transferred to column) / V (shear)) ratio at the connection - 0,50 m or 0,25 m. Seven internal slab-column joining were tested and ultimate loads, cracking, deflections, concrete and reinforcement strains were analyzed. The existence of hole adjacent to the smaller column dimension, the hole dimension, flexural reinforcement rate and placing, the variation of relation Mu/Vu in function of the load, and, than, of eccentricity of the load, influenced the slabs behavior and rupture load. Test results were compared with the estimations from CEB-FIP/MC1990 [7], EC2/2004 [12], ACI-318:2011 [1] and NBR 6118:2007 [5]. ACI [1] and EC2 [12] presented most conservative estimates, although have presented some non conservative estimates. Brazilian NBR [5], even though being partly based in EC2 [12], presented smaller conservative estimates and more non conservative estimates. A modification on all codes is proposed for taking in account the moment caused by the eccentricity at the critical perimeter for slabs with holes.

Railway Bridge CAD Software Program

2011 ◽  
Vol 403-408 ◽  
pp. 2893-2896
Author(s):  
Jia Wen Li ◽  
Zhi Xuan Pan ◽  
Hai Yan Zhang ◽  
Bang De Li
Keyword(s):  
Design Stage ◽  
Design Knowledge ◽  
Railway Bridge ◽  
Bridge Design ◽  
Geometric Data ◽  
Software Program ◽  
Design Software ◽  
Software Programs ◽  
Graphical System ◽  
Characteristic Component

After analyzing the features of all kinds of CAD software program, this paper reaches such a conclusion: most of traditional bridge-design programs focus on calculating structural load, so nowadays the calculating feature of this software programs is greatly improved. At the same time, a common problem is still with traditional bridge-design software programs, and this problem is all this programs don’t have any model that offer information referred to the bridge being designed, and this problem result in isolation of data in different stage of designing. To solve this problem, this paper proposes that railway bridge CAD software program take ACCESS as core database and AUTOCAD as supporting graphical system, and we should develop new software program on this basis. This paper also propose that bridge-design software program we develop in future should take design knowledge and bridge information referred to 3D geometric data in consideration, so that the design software program can reuse the characteristic component databases and all kinds of information in different design stage.

Signal Interpretation Considerations When Estimating Subglottal Pressure From Oral Air Pressure

2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield
Keyword(s):  
Standard Condition ◽  
Word Production ◽  
Air Pressure ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Air Leak ◽  
Pressure Signal ◽  
Adult Participants ◽  
Syllable Repetition ◽  
Subglottal Pressure

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.

Remarks on nonlinear elastic waves with null conditions

2020 ◽  
Vol 26 ◽  
pp. 121
Author(s):  
Dongbing Zha ◽  
Weimin Peng
Keyword(s):  
Initial Data ◽  
Global Existence ◽  
Elastic Waves ◽  
Wave Equations ◽  
Alternative Proof ◽  
Classical Solutions ◽  
Small Initial Data ◽  
Hyperelastic Materials ◽  
Variational Structure ◽  
Nonlinear Elastic

For the Cauchy problem of nonlinear elastic wave equations for 3D isotropic, homogeneous and hyperelastic materials with null conditions, global existence of classical solutions with small initial data was proved in R. Agemi (Invent. Math. 142 (2000) 225–250) and T. C. Sideris (Ann. Math. 151 (2000) 849–874) independently. In this paper, we will give some remarks and an alternative proof for it. First, we give the explicit variational structure of nonlinear elastic waves. Thus we can identify whether materials satisfy the null condition by checking the stored energy function directly. Furthermore, by some careful analyses on the nonlinear structure, we show that the Helmholtz projection, which is usually considered to be ill-suited for nonlinear analysis, can be in fact used to show the global existence result. We also improve the amount of Sobolev regularity of initial data, which seems optimal in the framework of classical solutions.

Review of operational indications on the design of facilities for radiopharmaceutical manufacturing in italy

2020 ◽  
Author(s):  
M.A. D’Avanzo ◽  
G.M. Contessa ◽  
G. Cocomello ◽  
M. Mattozzi ◽  
M. Pacilio ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Design Stage ◽  
Safety Aspects ◽  
Scientific Institutions ◽  
Available Information

Purpose. In this article, the authors propose useful operational indications to approach in the best possible way the issues concerning the design of a facility for manufacturing radiopharmaceuticals, with focus on organizational and safety aspects. Methods. Several documents produced by authoritative bodies, national and international scientific institutions and associations were examined and referenced, to the purpose of reviewing all available information in the field. Results. Indications are gathered for the design stage, including the organization of accesses and routes and characteristics and requirements of premises and systems. Conclusions. Main goal is to guide the reader in evaluating and choosing the most suitable features and equipment to limit the risks due to ionizing radiation and to prevent contamination of the workers and the environment.

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