scholarly journals Calculation of multilayer enclosing structures with middle layer of polystyrene concrete

2018 ◽  
Vol 193 ◽  
pp. 03020 ◽  
Author(s):  
Elena Korol ◽  
Marina Berlinova
Keyword(s):  
Middle Layer ◽  
Operating Conditions ◽  
Bending Moments ◽  
Rectangular Section ◽  
Strain Compatibility ◽  
Wall Structures ◽  
Wall Panels ◽  
Multilayer Wall ◽  
Combined Action ◽  
Concrete Elements

The strength and strain relations of characteristics of the layers in multilayer wall structures made of concrete of different strength are presented, the dependence of the stress values in the layers on the operating conditions of the structure is revealed. On the basis of the principle of strain compatibility of concrete and reinforcement, the estimation of the stress-strain state of multilayer wall panels is done taking into account the conditional concentrated shears in the joint between concretes. A calculation method is proposed, which is based on strains during the combined action of torque and bending moments of three-layer reinforced concrete elements with rectangular section in the stage of working with cracks.

scholarly journals Calculation features of wall panels with monolithic cement bond of layers in the stages of installation, transportation and maintenance

Vestnik MGSU ◽  
2019 ◽  
pp. 367-375 ◽  
Author(s):  
Elena A. Korol’ ◽  
Marina N. Berlinova
Keyword(s):  
Middle Layer ◽  
Structural Features ◽  
Design Parameters ◽  
Competitive Advantages ◽  
Design Standards ◽  
Wall Panels ◽  
Multilayer Wall ◽  
Current Design ◽  
Infinite Variety ◽  
Construction Practice

Introduction. When building residential, public and administrative buildings of various spatial structural designs (monolithic, precast-monolithic, precast, etc.), it is common practice to design self-sustaining (non-structural) outer walls within a storey. Developing and using new design and fabrication solutions of multilayer industrial-made wall panels in modern construction practice makes actual the issue of improving methods of their calculation in different stages of maintenance and under various sorts and combinations of loads and effects. However, there is an infinite variety of possible loading levels in practice and, therefore, the same variety of design approaches would be required. This is obviously unacceptable for engineering calculations, hence it is necessary to provide a monolithic matrix bond of layers, both technologically and structurally, which can provide a generalized approach to the calculation of multilayer enclosing structures in accordance with current design standards. Materials and methods. The article describes structural features of a multilayer wall panel made of structural concrete with the middle layer of concrete with low thermal conductivity and monolithic bond of layers. These features have an influence on creation of a design model and a calculation procedure in the stages of transportation, installation and maintenance. Results. The article has examined the structures described above in the sense of design parameters that provide their competitive advantages in strength and maintenance as compared with conventional mass-built enclosures. Conclusions. The studies demonstrate that when combining loads of force and non-force character, stresses in the considered structure do not exceed allowable values in all the stages what proves the prospects of using the multilayer panels with monolithic bond of layers for erection of various-purpose frame-panel buildings.

A Nitrogen Oxides Emission Prediction Model for Gas Turbines Based on Interpretable Multilayer Perceptron Neural Networks

2020 ◽  
Author(s):  
Dawen Huang ◽  
Shanhua Tang ◽  
Dengji Zhou
Keyword(s):  
Neural Networks ◽  
Nitrogen Oxides ◽  
Prediction Model ◽  
Working Conditions ◽  
Gas Turbines ◽  
Middle Layer ◽  
Operating Conditions ◽  
Nox Emission ◽  
Outlet Temperature ◽  
Output Layer

Abstract Gas turbines, an important energy conversion equipment, produce Nitrogen Oxides (NOx) emissions, endangering human health and forming air pollution. With the increasingly stringent NOx emission standards, it is more significant to ascertain NOx emission characteristics to reduce pollutant emissions. Establishing an emission prediction model is an effective way for real-time and accurate monitoring of the NOx discharge amount. Based on the multi-layer perceptron neural networks, an interpretable emission prediction model with a monitorable middle layer is designed to monitor NOx emission by taking the ambient parameters and boundary parameters as the network inputs. The outlet temperature of the compressor is selected as the monitorable measuring parameters of the middle layer. The emission prediction model is trained by historical operation data under different working conditions. According to the errors between the predicted values and measured values of the middle layer and output layer, the weights of the emission prediction model are optimized by the back-propagation algorithm, and the optimal NOx emission prediction model is established for gas turbines under the various working conditions. Furthermore, the mechanism of predicting NOx emission value is explained based on known parameter influence laws between the input layer, middle layer and output layer, which helps to reveal the main measurement parameters affecting NOx emission value, adjust the model parameters and obtain more accurate prediction results. Compared with the traditional emission monitoring methods, the emission prediction model has higher accuracy and faster calculation efficiency and can obtain believable NOx emission prediction results for various operating conditions of gas turbines.

Leakage Analysis of a High Pressure Flange Connection Under Bending Moments: An Analytic Procedure

2014 ◽  
Author(s):  
Matthias Bortz ◽  
Rolf Wink
Keyword(s):  
High Pressure ◽  
Contact Pressure ◽  
Fluid Pressure ◽  
Safety Margin ◽  
Bending Moment ◽  
Operating Conditions ◽  
Bending Moments ◽  
Spherical Lens ◽  
Flange Connection ◽  
Bolt Stress

High pressure flange connections for LDPE plants are designed using lens ring gaskets and bolted flange connections. The sealing principle is to achieve a high contact pressure between the spherical lens shape and the conical tube end. This contact pressure must exceed the fluid pressure by a safety margin under all operating conditions. Bending moments acting on the flange connection will create an uneven distribution of contact pressure over the lens ring surface. In this paper a procedure is shown to analyse the influence of the bending moment under consideration of internal pressure on a flange connection using 3-dimensional finite element models. The variations in bolt stress and distribution of contact pressures due to the bending moment are of specific interest. A first approach will be provided to derive some simplified design rules regarding leakage assessment of such flange connections.

Analytic solution of angle-ply laminated plates under extension, bending, and torsion

2019 ◽  
Vol 54 (8) ◽  
pp. 1093-1106
Author(s):  
Shen-Haw Ju ◽  
Wen-Yu Liang ◽  
Hsin-Hsiang Hsu ◽  
Jiann-Quo Tarn
Keyword(s):  
Numerical Solutions ◽  
Anisotropic Elasticity ◽  
Laminated Plates ◽  
Rectangular Section ◽  
State Space Approach ◽  
Present Solution ◽  
End Conditions ◽  
Combined Action ◽  
Space Approach

This paper develops a Hamiltonian state space approach for analytic determination of deformation and stress fields in multilayered monoclinic angle-ply laminates under the combined action of extension, bending, and torsion. The present solution satisfies the equations of anisotropic elasticity, the end conditions, the traction-free boundary conditions on the four edge surfaces of the rectangular section, and the interfacial continuity conditions in multilayered laminates. The proposed method only requires the solutions of matrix and eigen equations, regardless of the number or lamination of the layers. The finite element analyses are used to validate the accuracy of the analysis. The analytical solution and the numerical solutions are in excellent agreement.

scholarly journals Behavior of bearing reinforced concrete panels in the process of combined action

2019 ◽  
Vol 265 ◽  
pp. 05037 ◽  
Author(s):  
Dmitry Korolchenko
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Manufacturing Technology ◽  
Concrete Panels ◽  
Labour Costs ◽  
Combined Action ◽  
Concrete Elements ◽  
Deflection Rate ◽  
Important Significance

This research of has important significance in the constructive solution, manufacturing technology and labour costs. The irreversible changes in mechanical properties occur in reinforced concrete elements, decrease in compressive and tensile strength, additional deflections. In this paper, the goal was to assess the behavior of the bearing reinforced concrete panels with a combined action (fire and force) as close as possible to the actual effect in a fire. It was necessary to solve the following tasks: to determine the dependence of deflection and deflection rate on the heating of the plate and the load acting on the panel, to determine the amount of concrete falling before breaking the integrity of the panel (the formation of through cracks, determine the degree of heating of the panel from the duration of fire and force.

Effect of the ITZ Damage on Durability of Reinforced Concrete in Chloride Environment

1994 ◽  
Vol 370 ◽  
Author(s):  
Raoul François ◽  
Ginette Arliguie
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Concrete Structures ◽  
Operating Conditions ◽  
Reinforced Concrete Structures ◽  
Actual Operating ◽  
Chloride Environment ◽  
Concrete Elements ◽  
Transfer Properties ◽  
Salt Fog

AbstractThis paper deals with the effect of the ITZ on the service life of reinforced concrete. In the case of reinforced concrete structures, the penetration of chlorides does not depend only on concrete transfer properties but also on the loading applied, on the state of strains and on the exposure to the aggressive environment.In order to take into account these different parameters, we have performed experiments on reinforced concrete elements, over a long period. The samples used have to be of an adequate size (3 meters long) and stored in a salt fog in a loading state so as to be representative of the actual operating conditions of the reinforced concrete structures.The bending of the beams leads to the development of cracks which are neither preceded nor accompanied by microcracks, but the cement paste-aggregate interfaces are damaged in the tensile areas.The service loading of reinforced concrete has two consequences : firstly, a cracking with widths ranging between 0.05 mm and 0.5 mm according to the intensity of the mechanical strength applied. Secondly, a damage of the ITZ in the tensile areas causing an increase of chloride penetration directly proportional to the intensity of the stress applied to the beam.The model of the development of corrosion, worked out in relation with time and based on our results, emphasizes the influence of the paste-aggregate interface damage on the duration of the service life.

Longitudinal Bending and Torsional Moments Acting on a Ship Model at Oblique Headings to Waves

1960 ◽  
Vol 4 (02) ◽  
pp. 35-48
Author(s):  
Edward Numata
Keyword(s):  
Statistical Characteristics ◽  
Relative Importance ◽  
Bending Moments ◽  
Wave Direction ◽  
Lateral Bending ◽  
Ship Model ◽  
Bending Stresses ◽  
Longitudinal Bending ◽  
Combined Action

Tests were conducted with a model of a T2-SE-AI tanker running at oblique headings to waves to measure torsional moments and vertical and lateral components of longitudinal bending moments at the midship section. Trends of moments with speed and wave direction in regular long-crested waves of various lengths are presented. Statistical characteristics of moment responses at one speed and heading in irregular long-crested waves are given. The relative importance of lateral bending is explored by using model results to predict longitudinal bending stresses in a T-2 tanker deck caused by the combined action of vertical and lateral moments, and it is shown that lateral bending can contribute significantly to these stresses.

Predicted Response of the Die-Carrier Assembly in Flexible Electronics to the Combined Action of Tension and Bending Applied to the Carrier

2011 ◽  
Vol 79 (1) ◽  
Author(s):  
E. Suhir
Keyword(s):  
Mathematical Model ◽  
Normal Stress ◽  
Cross Sections ◽  
Flexible Electronics ◽  
Bending Moments ◽  
Analysis And Design ◽  
Tensile Forces ◽  
Combined Action ◽  
The Cross

A die-carrier assembly, subjected to the external tensile forces and bending moments applied to the flexible carrier is considered. The objective of the analysis is to develop a simple, easy-to-use, and physically meaningful predictive analytical (“mathematical”) model aimed at understanding the physics of the combined action of tension and bending experienced by the carrier and transmitted to the die through the more-or-less compliant bond. The addressed stresses include the interfacial shearing and peeling stresses, as well as the normal stress acting in the cross sections of the die. The obtained formulae can be used in the analysis and design of assemblies of the type in question.

Investigation of the simultaneous work of grillages and wall panels on full-scale reinforced-concrete elements

1965 ◽  
Vol 2 (5) ◽  
pp. 290-295
Author(s):  
S. V. Timofeev ◽  
A. I. Yushin ◽  
S. N. Shvedova
Keyword(s):  
Reinforced Concrete ◽  
Full Scale ◽  
Wall Panels ◽  
Concrete Elements

scholarly journals RESEARCH OF THE INFLUENCE OF LONGITUDINAL COMPRESSION ON THE STRENGTH OF THE WALL OF TWO-TURNED REINFORCED CONCRETE ELEMENTS WITH A CHARACTERISTIC EPURA BENDING MOMENTS IN THE AREA OF ACTION OF LATERAL FORCES

2021 ◽  
Vol 3 (72) ◽  
pp. 34-37
Author(s):  
A. Abdullaev .
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Experimental Studies ◽  
Compressive Force ◽  
Reinforced Concrete Beams ◽  
Bending Moments ◽  
Shear Forces ◽  
Longitudinal Compression ◽  
Lateral Forces ◽  
Concrete Elements

Experimental studies have been carried out to study the effect of longitudinal compression on the strength of the wall of I-beams of reinforced concrete beams.It has been established that with the central application of a longitudinal compressive force, the strength of the wall of I-beams of reinforced concrete beams with an alternating diagram of bending moments in the zone of action of transverse forces practically depends little on the degree of longitudinal compression.A comparative analysis of the results obtained with the results of similar experimental studies carried out on I-beam reinforced concrete beams with an unambiguous diagram of bending moments in the zone of action of shear forces is carried out.

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