scholarly journals Determination of the building products reliability parameters at different loads in a two-step mode

2019 ◽  
Vol 97 ◽  
pp. 04018
Author(s):  
Nadezhda Chiganova
Keyword(s):  
Assessment Process ◽  
Mode Switching ◽  
Building Structures ◽  
Reliability Parameters ◽  
Relevant Task ◽  
Second Mode ◽  
Construction Products ◽  
Reliability Performance ◽  
The Way

The reliability determination of building structures and their components in a two-step mode nowadays is a relevant task. The article studies the problem of determining the building structures and their components reliability performance in a two-step mode based on the results of the tests described. These tests were conducted as follows: the batch of products intended for test are first tested in the first mode, and then in the second mode. A certain moment of time for mode switching is selected randomly by a specified law. The product is then tested in the variable two-stage mode. During testing, moments of time of product operation in the first and second modes are registered. Two experimentation programs that differ in the way of mode switching are proposed: program tests and dynamic tests. Examples of the methodology application to the determination of the product failure rate were discussed. According to the results of theoretical and practical application of the proposed method, the way to determine the reliability parameters using different laws was suggested for application in structural analysis and construction products reliability assessment process.

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

Experimental research control methods of the spatial position of building constructions

2017 ◽  
Vol 922 (4) ◽  
pp. 7-12 ◽  
Author(s):  
G.A. Shekhovtsov ◽  
R.P. Shekhovtsova ◽  
D.P. Ivenin ◽  
O.V. Raskatkina
Keyword(s):  
Simultaneous Determination ◽  
Experimental Research ◽  
Vertical Plane ◽  
Error Theory ◽  
Spatial Position ◽  
Bridge Crane ◽  
Building Structures ◽  
Control Methods ◽  
Engineering Geodesy

The article contains the method of discrete scanning points in the vertical plane of the columns and roof trusses for the simultaneous determination of vertical columns, the distance between them in flight at their tip and deflection farms with one point standing and only one performer. The technique is based on the use of reflectorless electronic tachymeter and its SDh key. Experimental research of methods on the elements of building structures NNGASU educational housing using electronic tachymeter SET530R. Results of the experiments were monitored by a coordinate and photographic methods, as well as with the developed at the chair of Engineering Geodesy laser-mirroring device designed to measure inaccessible or hard to reach distances. Analysis methods of error theory position and the results of its comparison with other methods have shown that it provides the required accuracy, easy to perform, does not require the output of the observer on the crane path or lift to the towers, free from the multiple engagement of the bridge crane and can be successfully applied on practice.

scholarly journals Universal Synthesizer of Mueller Matrices Based on the Symmetry Properties of the Enpolarizing Ellipsoid

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 983
Author(s):  
José J. Gil ◽  
Ignacio San José
Keyword(s):  
Mathematical Structure ◽  
Mueller Matrix ◽  
Morphological Properties ◽  
Nondestructive Analysis ◽  
Structural Decomposition ◽  
Symmetry Properties ◽  
Mueller Matrices ◽  
Scattering Measurement ◽  
The Way

Polarimetry is today a widely used and powerful tool for nondestructive analysis of the structural and morphological properties of a great variety of material samples, including aerosols and hydrosols, among many others. For each given scattering measurement configuration, absolute Mueller polarimeters provide the most complete polarimetric information, intricately encoded in the 16 parameters of the corresponding Mueller matrix. Thus, the determination of the mathematical structure of the polarimetric information contained in a Mueller matrix constitutes a topic of great interest. In this work, besides a structural decomposition that makes explicit the role played by the diattenuation-polarizance of a general depolarizing medium, a universal synthesizer of Muller matrices is developed. This is based on the concept of an enpolarizing ellipsoid, whose symmetry features are directly linked to the way in which the polarimetric information is organized.

scholarly journals Mitigating natural events to avoid disaster in public school buildings: seismic retrofitting of SDN 42 Korong Gadang

2018 ◽  
Vol 229 ◽  
pp. 02021
Author(s):  
James Mwangi ◽  
Laura Putri ◽  
Listhbeth Collins
Keyword(s):  
School Facilities ◽  
Seismic Retrofitting ◽  
Building Structures ◽  
National Agency ◽  
Electrical Grid ◽  
The North ◽  
Australian Plate ◽  
West Sumatra

With over 50 million students, Indonesia has the fourth largest education system in the world. The first twelve years of education are compulsory for all citizens. The students, together with over 3 million teachers spend six (or five in some cases) days a week at over 300,000 schools, typically from 6:30 AM to 2 (or 3) PM. Geographically, Indonesia is traversed by the infamous “ring of fire” and prone to natural events resulting from the tectonic plate movements of the Australian Plate from the South, the Eurasian and Sunda Plates from the North and the Philippine Plate from the East. Left unmitigated, these natural events would lead to natural disasters emanating from resulting earthquakes and leading to tsunamis, landslides, the collapse of building structures and failure of lifelines (roads, pipelines, electrical grid, etc.). In an effort to provide disaster-safe schools, the National Agency for Disaster Management has required that school facilities be a community center in case of disasters and serve as emergency shelters. Retrofit of existing buildings will be needed to comply with government guidelines. This paper presents a case study of the determination of structural deficiencies of an existing school building in SDN 42 Korong Gadang, Padang, West Sumatra and implementation of a seismic retrofit (design and construction) at the same building to mitigate potential earthquake disaster.

scholarly journals The use of classical methods and neural networks in deformation studies of hydrotechnical objects

2020 ◽  
Vol 12 (1) ◽  
pp. 718-725
Author(s):  
Maria Mrówczyńska ◽  
Jacek Sztubecki ◽  
Małgorzata Sztubecka ◽  
Izabela Skrzypczak
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Cylinder Surface ◽  
Building Structures ◽  
Steel Cylinder ◽  
Factors Affecting ◽  
Initial Stage ◽  
Artificial Neural ◽  
Set Of Points

Abstract Objects’ measurements often boil down to the determination of changes due to external factors affecting on their structure. The estimation of changes in a tested object, in addition to proper measuring equipment, requires the use of appropriate measuring methods and experimental data result processing methods. This study presents a statement of results of geometrical measurements of a steel cylinder that constitutes the main structural component of the historical weir Czersko Polskie in Bydgoszcz. In the initial stage, the estimation of reliable changes taking place in the cylinder structure involved the selection of measuring points essential for mapping its geometry. Due to the continuous operation of the weir, the points covered only about one-third of the cylinder area. The set of points allowed us to determine the position of the cylinder axis as well as skews and deformations of the cylinder surface. In the next stage, the use of methods based on artificial neural networks allowed us to predict the changes in the tested object. Artificial neural networks have proved to be useful in determining displacements of building structures, particularly hydro-technical objects. The above-mentioned methods supplement classical measurements that create the opportunity for carrying out additional analyses of changes in a spatial position of such structures. The purpose of the tests is to confirm the suitability of artificial neural networks for predicting displacements of building structures, particularly hydro-technical objects.

scholarly journals III. Further experiments on the vapour densities of potassium and sodium

1879 ◽  
Vol 29 (196-199) ◽  
pp. 490-493 ◽  
Keyword(s):  
Considerable Error ◽  
Exact Determination ◽  
The Way

In one former communication “On the Vapour Densities of Potas­sium and Sodium,” we pointed out the chief obstacles which lay in the way of an exact determination of these constants. Having overcome the chief manipulative difficulties in connexion with the method we described, there still remained the problem for solution as to how far the use of iron bottles in our experiments might affect the results. If the iron retained the metals or allowed their vapours to diffuse with rapidity through it, a considerable error might be produced without its being easily detected.

The concept of calculating the actual limit of fire resistance of building structures

2021 ◽  
pp. 12-17
Author(s):  
Юрий Николаевич Шебеко ◽  
Алексей Юрьевич Шебеко
Keyword(s):  
Fire Resistance ◽  
Fire Safety ◽  
Building Structures ◽  
Safety Level ◽  
Fire Temperature ◽  
Normative Documents ◽  
Software Complex ◽  
Temperature Regimes ◽  
Actual Fire

Проведен краткий анализ понятий, связанных с расчетом пределов огнестойкости строительных конструкций. Дано определение термина «фактический предел огнестойкости», которое отсутствует в нормативных документах по пожарной безопасности. Отмечено, что это связано с использованием на практике значений пределов огнестойкости, определенных для стандартных температурных режимов пожара, в то время как на практике указанные температурные режимы, как правило, отличаются от стандартных. Предложена концепция определения фактического предела огнестойкости, основанная на моделировании воздействия на строительную конструкцию температурного режима реального пожара (например, с помощью программного комплекса FDS 6). The brief analysis of definitions connected with estimation of fire resistance limits of building structures is conducted. There is given the determination of term “actual fire resistance limit” that is absent in fire safety normative documents. It is caused by practical application of the fire resistance limits determined for standard temperature regimes of fires only, but at the same time the temperature regimes of real fires as a rule differ from the standard regimes. There is proposed the method for determination of the actual fire resistance limit based on the modeling of influence of the real fire temperature regime on buildings structures. This modeling can be made by an application of CFD methods (for example, with the help of FDS 6 software complex). The required reliability of the building structure is considered. The proposed method can solve the problem of practical applicability of certain structural unit during designing buildings and structures, for which the use of the resistance limits obtained for the standard fire temperature regimes can lead to unjustified economic expenditures without an appropriate elevation of fire safety level of the object.

On the Inadequacy of existing Data for determining the Rate of Mortality among Select Lives

1854 ◽  
Vol 4 (1) ◽  
pp. 1-9
Author(s):  
William Spens
Keyword(s):  
First Year ◽  
Sufficient Data ◽  
Existing Data ◽  
Selection Of ◽  
The Way

I. While so much improvement has recently taken place in the arrangement and construction of various tables for facilitating calculations founded on existing data, very little has been done in the way of investigating and correcting the data themselves; and it is feared that the question of the rate of mortality among select lives is still involved in the greatest doubt and obscurity.II. It is not proposed in the present paper to go farther than to show that the rate of mortality, during the first year of selection, of select assured lives is so materially different from what it has hitherto been represented, as to lead to the inference that the data from which the erroneous deduction has been made cannot be true data for the ascertainment of the value of selection. To investigate the rate of mortality of select lives at separate ages, I conceive to be of the utmost importance for the elucidation of truth, and the proper direction of sanatory inquiries; but I do not consider that sufficient data at present exist for the determination of this, and these can only be obtained by a united inquiry. I shall be very happy if the present observations have any effect in hastening such an investigation, which sooner or later must be entered upon.

Study on Calculation of Rock Pressure and Determination of Depth for Shallow Asymmetric Tunnel

2011 ◽  
Vol 261-263 ◽  
pp. 1034-1038 ◽  
Author(s):  
Xiao Jun Zhou
Keyword(s):  
Rock Pressure ◽  
Calculation Method ◽  
Tunnel Structure ◽  
The Way

The method to calculate rock pressure for shallow asymmetric tunnel is analyzed by means of taking a mountainous tunnel with semicircular crown and straight sidewall as the object in this paper. The calculation method of tunnel rock pressure has been presented with consideration of both tunnel structure size and its overburden depth. Finally the way to determine the shallow or profound depth of asymmetric tunnel is also obtained.

scholarly journals Statistical error in counting experiments

1935 ◽  
Vol 149 (868) ◽  
pp. 467-486 ◽  
Keyword(s):  
Finite Number ◽  
Statistical Error ◽  
Single Particles ◽  
Exact Determination ◽  
Statistical Laws ◽  
The Way

Experiments in which single particles are studied with the aid of counters would, in principle, lead to an exact determination of the statistical laws governing the behaviour of these particles if the number of counted particles were infinitely large. With a finite number of counts, however, a finite statistical error will always remain. This error depends upon the number of counts and upon the way in which one makes use of the counter readings to calculate the parameters entering into the statistical laws. The purpose of the following investigation is to show for some typical cases which way of calculating has to be adopted in order to make the error a minimum.

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