scholarly journals THE ENGINEERING METHOD FOR UNIFYING GROUND FLOOR SLAB SETTLEMENTS

2021 ◽  
Vol 12 (2) ◽  
pp. 46-52
Author(s):  
Kęstutis Urbonas ◽  
Danutė Sližytė ◽  
Antanas Šapalas
Keyword(s):  
Engineering Method ◽  
Pile Foundations ◽  
Floor Slab ◽  
Ground Floor ◽  
Actual Behaviour ◽  
Industrial Buildings ◽  
Calculation Results ◽  
The Impact

For industrial buildings and logistics centres truck lifts are usually used. Therefore, there are special requirements for flatness tolerance of ground floor. The ground floor settlements differences in selected distances are limited. The article reviews the behaviour of soils and the importance of the actual behaviour assessment of soils during the design of floor slab on elastic subgrade. Particular attention is given to the behaviour of floor slab areas above pile foundations that support the building’s columns. Calculation results show the impact of subgrade stiffness on the behaviour of the floor slab, especially in areas above pile foundations, where the stiffness of subgrade is much higher. The article presents a solution for achieving the required level of settlements’ differences in areas where pile foundations for the building’s columns under the ground slab are used. The paper proposes an efficient engineering method to reduce ground slab settlements differences. The results of performed calculations confirm the efficiency of presented method.

scholarly journals A Novel Integrated Approach to Solve Industrial Ground Floor Design Problems

2020 ◽  
Vol 12 (12) ◽  
pp. 4809
Author(s):  
Zenonas Turskis ◽  
Kęstutis Urbonas ◽  
Danutė Sližytė ◽  
Jurgis Medzvieckas ◽  
Rimantas Mackevičius ◽  
...  
Keyword(s):  
Design Method ◽  
Integrated Approach ◽  
Pile Foundations ◽  
Actual Behavior ◽  
Ground Floor ◽  
Integrated Method ◽  
Industrial Buildings ◽  
Reaction Coefficient ◽  
Pile Cap ◽  
The Impact

The ground floors of buildings usually have high loads from racks and other storage equipment in industrial buildings and logistics centers. Such types of buildings commonly require lift trucks. Therefore, there are special requirements for flatness tolerance across and along the driving track of truck lifts. Structural design solutions must be optimized and sustainable. The article reviews the behavior of soils and the importance of the actual behavior assessment of soils during the design of the ground floor on the elastic subgrade. The behavior of the ground floor’s areas above pile foundations that support the building’s columns is essential. Calculation results show the impact of subgrade stiffness on the behavior of reinforced concrete (RC) floor slab, especially in areas above pile foundations, where the stiffness of subgrade is much higher. The research provides a solution to achieve the required level of settlement dissimilarity in areas where there are piles underneath a building slab under the columns. The paper proposes a new integrated method for the evaluation of the subgrade reaction coefficient above the pile cap. The proposed method optimizes design time and eliminates the need for specialized geotechnical software. Obtained results confirmed the efficiency of the proposed design method.

Sail Aero-Structures: Studying Primary Load Paths and Distortion

2005 ◽  
Author(s):  
Robert Ranzenbach ◽  
Zhenlong Xu
Keyword(s):  
Aerodynamic Load ◽  
Element Analysis ◽  
Strain Behavior ◽  
Construction Methods ◽  
Load Paths ◽  
Calculation Results ◽  
Computational Fluid Dynamics Cfd ◽  
Aerodynamic Field ◽  
The Impact ◽  
Primary Load

A method is described to conduct an integrated Fluid-Structure Interaction (FSI) simulation of sails that is based upon knowledge of the sail’s design shape geometry and membrane material properties. A Finite Element Analysis (FEA) of the sail structure and a Computational Fluid Dynamics (CFD) model of the aerodynamic field are combined and iteratively solved to compute the actual flying shape of the sail under aerodynamic load, the stress strain behavior of the sail membrane, the integrated aerodynamic forces produced by the sail such as driving force and heel moment, and the resulting loads on sheets, halyards, etc. An important contribution of this particular method is the incorporation of wrinkling phenomena into the FEA portion of the calculation. Results from a study of working sails for a 30’ MORC racing yacht designed by Nelson-Marek (NM) in the 1990’s are presented and discussed with particular emphasis on the variability of primary load paths with changing trim and sailing conditions as well as the impact of sail deformation in the direction of relatively small stresses that is often poorly addressed in many proprietary sail construction methods.

scholarly journals ON THE ISSUE OF DETERMINING THE CRITICAL CUTTING SPEED OF THE MECHANISM FOR FORMING AND TRIMMING THE FALSE EDGE OF THE DORNIER RAPIER LOOM

2021 ◽  
Vol 53 (3) ◽  
pp. 37-40
Author(s):  
Svitlana V. Bukina ◽  
Tatiana A. Sitnikova
Keyword(s):  
Rational Design ◽  
Mutual Influence ◽  
Cutting Speed ◽  
Design Parameters ◽  
Working Process ◽  
Forming Mechanism ◽  
Rational Design Parameters ◽  
Calculation Results ◽  
Knife Blade ◽  
The Impact

In this paper, an attempt is made to develop a method for determining the critical cutting speed of the threads of the false edge of the edge-forming mechanism of the weaving rapier machine. The proposed calculation method takes into account the impact nature of the cutting process at a critical speed, which allows taking into account the mutual influence of the parameters of the working process and more fully assess the mechanics of this process, in which the intensity of the cutting force and the value of the contact stress take the maximum value. The paper calculates the critical cutting speed for some of the main types of threads used and the parameters of the knife blade. The presented calculation results can be used to select rational design parameters of the knife blade, depending on the type of processed threads, when designing and researching new edge-forming mechanisms on looms.

scholarly journals EXPERIMENTAL STUDIES OF PILE FOUNDATION GROUND BASE REINFORCED WITH HARD INCLUSIONS

2019 ◽  
Vol 10 (3) ◽  
pp. 5-15
Author(s):  
M. L Nuzhdin
Keyword(s):  
High Pressure ◽  
Pile Foundation ◽  
Experimental Studies ◽  
Pile Foundations ◽  
Foundation Model ◽  
Series Of Experiments ◽  
Bored Piles ◽  
Soil Foundation ◽  
High Pressure Injection ◽  
The Impact

Often in construction practice there is a need to strengthen the pile foundation of buildings and structures. The traditional methods include the implementation of additional, as a rule, bored piles with the subsequent erection of a grillage incorporating them into operation. Often, this work has to be done in the conditions of dense urban development, in cramped rooms of the basement, etc., which leads to significant technological difficulties. One of the alternative ways to strengthen pile foundations is the method of high-pressure group injection, which consists in injecting a movable cement-sand mortar into the soil under pressure that exceeds its structural strength. As a result, after its hardening, solid injection bodies are formed at the base, reinforcing the soil base. The article describes the results of experiments to assess the impact of the layout of hard inclusions on the deformability of the soil foundation of the pile foundation model. The experiments were carried out in a small soil tray, which was filled with medium-grained loose sand. The piles were modeled with metal rods, the pile grillage with a metal square stamp. The pile foundation model included 9 piles arranged in a square grid. As injection bodies, gravel grains of various sizes and shapes were used. The studies included 10 series of experiments (each experiment was repeated at least 3 times): the volume of the inclusions used, their sizes, the positioning step in the plan and in depth varied. As a result of the analysis of the performed experiments, conclusions were formulated regarding the purpose of the optimal layout of hard inclusions when strengthening the soil foundation of pile foundations by high-pressure injection of mobile cement-sand mixtures.

Uticaj armirano betonskog stuba na raspodelu magnetskog polja mešovitog voda

2020 ◽  
Vol 22 (1-2) ◽  
pp. 58-64
Author(s):  
Teodora Gavrilov ◽  
◽  
Karolina Kasaš-Lažetić ◽  
Kristian Haška ◽  
Miroslav Prša
Keyword(s):  
Magnetic Field ◽  
Field Distribution ◽  
Magnetic Field Distribution ◽  
Magnetic Flux Density ◽  
Reinforcing Bars ◽  
Magnitude Distribution ◽  
Calculation Results ◽  
Mixed Power ◽  
The Impact ◽  
The Magnetic Field

In this paper, the analysis of magnetic field distribution of overhead mixed power line (20 kV/0.4 kV) supported by reinforced concrete towers, named MNL-12 is presented. The impact of ferromagnetic, conductive parts of the pylons (reinforcing bars, billets and cross arm beams) on magnetic field distribution is investigated. The numerical calculations were performed in COMSOL Multiphysics program package on simplified 2D model. The main goal of the calculations was to examine the impact of currents induced in ferromagnetic conductive parts on magnetic field produced by currents in the power system’s conductors. The calculation results are presented graphically, as the diagrams of the magnetic flux density magnitude distribution in the tower plan, normal to the system’s axe. The calculation results demonstrated that the magnetic field of induced currents decreases the magnetic field produced by the currents of overhead power system.

scholarly journals Effects of different nuclear evaluation data on the RMC keff calculation

2020 ◽  
Vol 239 ◽  
pp. 19005
Author(s):  
Zhang Wenxin ◽  
Qiang shenglong ◽  
Yin qiang ◽  
Cui Xiantao
Keyword(s):  
Cross Section ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Neutron Cross Section ◽  
Nuclear Data ◽  
Section Data ◽  
Calculation Results ◽  
The Impact ◽  
Physical Calculation

Neutron cross section data is the basis of nuclear reactor physical calculation and has a decisive influence on the accuracy of calculation results. AFA3Gassemble is widely used in nuclear power plants. CENACE is an ACE format multiple-temperature continuous energy cross section library that developed by China Nuclear Data Centre. In this paper, we calculated the AFA3G assemble by RMC.We respectively used ENDF6.8/, ENDF/7 and CENACE data for calculation. The impact of nuclear data on RMC calculation is studied by comparing the results of different nuclear data.

scholarly journals CATHARE Assessment of Natural Circulation in the PKL Test Facility during Asymmetric Cooldown Transients

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Anis Bousbia Salah ◽  
Jacques Vlassenbroeck
Keyword(s):  
Natural Circulation ◽  
Test Facility ◽  
Steam Generators ◽  
Calculation Results ◽  
The Impact

Results of the CATHARE code calculations related to asymmetric cooldown tests in the PKL facility are presented. The test under consideration is the G2.1 experiment performed within the OECD/NEA PKL-2 project. It consists of carrying out a cooldown under natural circulation conditions in presence of two (out of four) emptied Steam Generators (SGs) and isolated on their secondary sides. The main goal of the current study is to assess the impact of a chosen cooldown strategy upon the occurrence of a Natural Circulation Interruption (NCI) in the inactive (i.e., noncooling) loops. For this purpose, three G2.1 test runs were investigated. The calculation results emphasize, mainly, the effect of the cooldown strategy, and the conditions that could lead to the occurrence of the NCI phenomenon.

Impact Study of Mass Eccentricity of Sniper Rifle Bullet on Initial Disturbance

2014 ◽  
Vol 1006-1007 ◽  
pp. 275-279
Author(s):  
Guo Qing Liu ◽  
Cheng Xu
Keyword(s):  
Angular Displacement ◽  
Great Influence ◽  
Coupling Model ◽  
Initial Position ◽  
Initial Disturbance ◽  
Mass Center ◽  
Nonlinear Finite Element Method ◽  
Mass Eccentricity ◽  
Calculation Results ◽  
The Impact

The bullet-rifle coupling model of sniper rifle has established to study the impact of bullet mass eccentricity on initial disturbance. This coupling model was established based on nonlinear finite element method and used to simulate the launch process of sniper rifle under the condition of gravity static equilibrium in the method of the mixing calculation which had advantages of both dynamic explicit algorithm and static implicit algorithm. The impact of different initial position of mass center on bullet swing angular displacement and centroid displacement was considered. Numerical calculation results shows that bullet mass eccentricity has a great influence on initial disturbance, the bullet swing angular displacement and centroid displacement is closely related to initial position of mass center. In addition, there is proportionality between bullet swing angular displacement and axial velocity before it reaches limit. That is helpful to carry out further study of how to control the influence of mass eccentricity on initial disturbance.

scholarly journals Research on Blade-Casing Rub-Impact Mechanism by Experiment and Simulation in Aeroengines

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Jie Hong ◽  
Tianrang Li ◽  
Zhichao Liang ◽  
Dayi Zhang ◽  
Yanhong Ma
Keyword(s):  
High Speed ◽  
High Performance ◽  
Element Model ◽  
Physical Parameters ◽  
Test Rig ◽  
Calculation Results ◽  
Rotor Support ◽  
Blade Tip ◽  
Set Up ◽  
The Impact

Aeroengines pursue high performance, and compressing blade-casing clearance has become one of the main ways to improve turbomachinery efficiency. Rub-impact faults occur frequently with clearance decreasing. A high-speed rotor-support-casing test rig was set up, and the mechanism tests of light and heavy rub-impact were carried out. A finite element model of the test rig was established, and the calculation results were in good agreement with the experimental results under both kinds of rub-impact conditions. Based on the actual blade-casing structure model, the effects of the major physical parameters including imbalance and material characteristics were investigated. During the rub-impact, the highest stress occurs at the blade tip first and then it is transmitted to the blade root. Deformation on the impact blade tip generates easily with decreased yield strength, and stress concentration at the blade tip occurs obviously with weaker stiffness. The agreement of the computation results with the experimental data indicates the method could be used to estimate rub-impact characteristics and is effective in design and analyses process.

scholarly journals Using rigidity elements to strengthen one-storey buildings frames

2018 ◽  
Vol 196 ◽  
pp. 02017
Author(s):  
Oleg Veremeenko
Keyword(s):  
Reinforced Concrete ◽  
Concrete Columns ◽  
Reinforced Concrete Frame ◽  
Limit Values ◽  
Building Frame ◽  
Concrete Frame ◽  
Industrial Buildings ◽  
Calculation Results ◽  
Force Variation ◽  
Influence Degree

The study focuses on strengthening industrial buildings frames by introducing rigidity elements. Materials concentration principle in rigidity elements in the form of reinforced concrete columns is used and the influence degree on a building frame operation is estimated. This changes the performance of the overlay disk as an element that distributes horizontal forces. The paper describes basic dependencies determining the correlation between rigidity characteristics of rigidity elements and ordinary columns. They are determined by reinforced concrete frame movements when the lower section columns moments reach limit values. In resulting exposure rigidity elements accept basic horizontal efforts, and ordinary columns work as centrally compressed. Calculation results are presented as graphs of force variation depending on correlation between rigidity characteristics of rigidity elements and ordinary columns. The paper outlines that after introducing rigidity elements they act as basic distributing horizontal loads element. The overlay disk has the final load bearing capacity and regulates the limit distances between rigidity elements. The introduction of rigidity elements into the building frame should be accompanied by appropriate measures to strengthen structure foundations. The research proves that this method of one-storey industrial buildings frames reinforcement enables to use materials and technologies during reconstruction more efficiently.

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