scholarly journals Experimental study on an overhead crane passing a rail track joint

2021 ◽  
pp. 98-102
Author(s):  
N. M. Fidrovska ◽  
O. V. Chernyshenko ◽  
I. A. Perevoznyk
Keyword(s):  
Strain Measurement ◽  
Direct Method ◽  
Metal Structure ◽  
Main Beam ◽  
Overhead Crane ◽  
Magnification Factor ◽  
Extreme Position ◽  
Metal Structures ◽  
Rail Track ◽  
Dynamic Magnification Factor

Purpose. To confirm the theoretical conclusions that determining the load from the wheel impact with the joint of rails in the metal structures of overhead cranes used in the technological processes at ore mining and processing mills and integrated works and moving along the rail tracks requires that the dynamic magnification factor should take into account the trolley position. Methodology. To assess the load to which the crane metal structures are exposed the electric strain measurement method using direct bridge circuit was chosen. To calibrate the strain measurement system, the direct method was used, under which calibration is performed directly on the structure on which experimental studies will be carried out in the future. Findings. It was established that the dynamic magnification factor in the metal structure of the overhead crane had the following values when passing the last rail joints: 1.54 (with the trolley in the middle of the bridge), 2.46 (with the trolley at 0.25 of the crane span from the end beam), 3.33 (with the trolley in the extreme position). So, with the trolley being at a distance of 0.25 of the crane span from the end beam, the dynamic magnification factor is 74%, and with the trolley in the middle of the bridge, it is 46% of the dynamic magnification factor if the trolley is in its extreme position. Originality. The scientific novelty consists in the first experimental confirmation of the results obtained in the theoretical studies on the overhead crane passing the joints of the rail track with regard to the crane trolley position, which leads to changes in the stiffness of the main beam in the interval between the trolley and the final beam. Practical value. The results obtained enable calculations on the crane bridge metal structure during the design and repair of the main and end beams taking into account the value of the dynamic magnification factor, which allows increasing the reliability and durability of the crane metal structure as a whole.

Study on Dynamic Behavior of Ancient Timber Structures Roof

2013 ◽  
Vol 475-476 ◽  
pp. 1559-1562
Author(s):  
Jun Dai
Keyword(s):  
Dynamic Behavior ◽  
Vibration Isolation ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Maximal Response ◽  
Construction Technology ◽  
Magnification Factor ◽  
Finite Element Software ◽  
Moderate Earthquake ◽  
Dynamic Magnification Factor

The roof model of the palace timber buildings was established according to the construction technology of the Ying-tsao fa-shih. Based on its analysis of dynamic behavior with shaking table test and ANSYS finite element software, the dynamic behavior of structure and its maximal response under different conditions were gotten, and also the dynamic magnification factor of the beams layer and the whole structure were gotten, at last the results got by shaking table test was compared with the numerical simulation. Research shows that the nature frequency of the model is 1.486 Hz which is much bigger than that of the whole structure; the maximal displacement of beam layer gradually increases with the increase of ground motion intensity and the height of structure; the vibration isolation performance of semi-rigid tenon-mortise joints in rare earthquake (400gal) is better than that in moderate earthquake (220gal) and frequent earthquake (110gal); the dynamic magnification factor between layers was about 1, and roof 0.9 or so.

Economical design for long-span soil – metal structures

1996 ◽  
Vol 23 (4) ◽  
pp. 838-849 ◽  
Author(s):  
Hesham Mohammed ◽  
John B. Kennedy
Keyword(s):  
Dimensional Analysis ◽  
Structural Engineering ◽  
Three Dimensional ◽  
Metal Structure ◽  
Reinforced Soil ◽  
Soil System ◽  
Metal Structures ◽  
Long Span ◽  
Economical Design ◽  
Soil Metal

Soil – metal structures consisting of metal conduits covered with soil have been used extensively for short-span bridges. Recently, some designers ventured into utilizing them for longer spans with shallow soil cover which has led to some failures. Long-span soil – metal structures are often designed with transverse stiffeners attached to the metal structure. Another approach is the use of a reinforced-soil system in which the surrounding soil is reinforced and the metal conduit is tied into the soil. In this paper, a three-dimensional analysis of long-span soil – metal structures is carried out using these two approaches. The analysis is verified and substantiated by results from laboratory models. The structural responses from the two designs show that the latter design approach leads to a more economical structure. A design example based on the Cheese Factory Bridge built in Ontario in 1984 is presented. Key words: bridges, design, long span, reinforced soil, soil – metal structures, structural engineering, three-dimensional analysis.

Study on the Characters of Seismic Response Spectra Based on China Financial Information Mansion

2014 ◽  
Vol 580-583 ◽  
pp. 1729-1733
Author(s):  
Ming Li ◽  
Yuan Qing Wang ◽  
Wei Tao ◽  
Bin Wang ◽  
Qing Xian Yu ◽  
...  
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Response Spectra ◽  
Financial Information ◽  
Amplification Coefficient ◽  
Response Analysis ◽  
Magnification Factor ◽  
Characteristic Period ◽  
Seismic Coefficient ◽  
Dynamic Magnification Factor

Rare study is done on floor response spectrum of super-high rise building, but it is an important condition for the seismic response analysis of floor subsidiary structure. Therefore, based on the early calculation model of China Financial Information Mansion, the floor response spectrum is calculated under different input ground motion. The floor and ground response spectrum is compared with each other from the seismic coefficient, dynamic amplification coefficient, characteristic period and the form of response spectrum. The results shows that: the floor seismic coefficient and the magnification coefficient are greater or smaller than the ground ones, the biggest difference of which is nearly 1 times; all the floor character period are greater than the ground ones, the biggest difference of which is over 60%; there are obvious differences between the floor and ground dynamic magnification factor spectra form under some conditions, of which the second peak of the former one is probably very large, even near to the peak of the first one, while the latter has no such phenomenon. Therefore, during the process of calculating the seismic response of floor subsidiary structure, it is necessary to consider the change of floor seismic coefficient, dynamic magnification factor, characteristic period and spectra form based on the main structure.

Direct and Indirect Strain Measurement of Flexible Printed Circuit Boards - fPCBs

2013 ◽  
Vol 655-657 ◽  
pp. 88-93 ◽  
Author(s):  
Luciano Arruda ◽  
Cristiano Coimbra ◽  
João Marco Andolfatto
Keyword(s):  
Strain Gauge ◽  
Strain Measurement ◽  
High Speed ◽  
Printed Circuit Boards ◽  
Direct Method ◽  
Indirect Measurement ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Polyimide Substrate ◽  
Flexible Printed Circuit

This work is related to reliability of strain measurement in flexible printed circuit boards (fPCBs) made with polyimide substrate. It was observed that the fPCBs are very sensitive to strain mounting stiffness. The indirect measurement method will be done employing High Speed Camera (HSP). The direct method will be formulated in two ways: 1) conventional strain gauge glued in an fPCBs; 2) printed strain gauge in a polyimide substrate. This paper will point out mistakes and show advantages when using different method to extract the deformation field of the selected area in a flexible thin film.

Hydraulic Mental Structure Health Diagnosis Weighting Method

2014 ◽  
Vol 494-495 ◽  
pp. 925-931
Author(s):  
Kun Yang ◽  
Guang Ming Yang ◽  
Yong Huang ◽  
Pan De Jing
Keyword(s):  
Information Diffusion ◽  
Information Gain ◽  
Fuzzy Theory ◽  
Metal Structure ◽  
Weighting Method ◽  
Metal Structures ◽  
New Ideas ◽  
Multi Level ◽  
Weighting Methods ◽  
Health Diagnosis

By means of inductive analysis the health diagnosis weighting methods in engineering, this paper discusses the basic principle, advantages, disadvantages and applicable scope of weighting methods. On the basis, combining with multi-level, multi-standard and multi-factor characteristic of hydraulic metal structures health diagnosis, the methods of AHP, information gain, information diffusion and improved entropy are studied, which are applicable to hydraulic metal structures health diagnosis weighting. Based on fuzzy theory, the fuzzy multi-level comprehensive weighting method is put forward and studied, which combined both subjective and objective method advantages and its complementary. In addition, it provides the necessary theory foundation and new ideas for the development of hydraulic metal structure health diagnosis technology.

scholarly journals Research on Construction and Sizing of the Metal Structure of a Winding Installation

2021 ◽  
Vol 44 (2) ◽  
pp. 11-16
Author(s):  
Marin-Silviu NAN ◽  
Dorina BĂDIȚĂ (POPESCU) ◽  
Danut GRECEA ◽  
Cosmin VITAN ◽  
Bogdan BRĂNIȘTEANU
Keyword(s):  
Analytical Calculation ◽  
Metal Structure ◽  
Metal Structures ◽  
The Real

The paper focuses on the design of the metal tower for the sinking of Netiș de-ventilating shaft in Râul Mare Retezat hydro-energetic setup. The analytical calculation of sizing and verification of the metal structure is doubled by the graphic simulation with speciality software, in view of obtaining results as close as possible to the real exploitation conditions of the tower. The tower of the de-ventilating shaft is considered to be a temporary construction, and its component parts will be decommissioned once the sinking is finalized. The tower is made up of metal structures in four transoms, 3 being mounted with junction plates and screws, the fourth being the roof.

scholarly journals EXPERIMENTALSTUDY OF DYNAMIC EFFORTS DURING THE OPERATION OF THE MECHANISM OF MOVEMENT OF THE CARGO TROLLEYOF AN OVERHEAD CRANE

2021 ◽  
pp. 60-69
Author(s):  
Nataliia Fidrovska ◽  
Evgen Slepuzhnikov ◽  
Roman Ponomarenko ◽  
Dmytro Kozodoi
Keyword(s):  
Friction Pair ◽  
Evaluation Criteria ◽  
Rolling Friction ◽  
Technical Condition ◽  
Overhead Crane ◽  
Rail Track ◽  
Stage Of Development ◽  
Rolling Surface ◽  
Running Wheels ◽  
Shock Pulses

The article deals with the determination of the dynamic loads arising in the running wheels of a conventional (standard) and modernized design during the movement of the cargo carriage of an overhead crane. The redesigned wheel has an insert made from 7-7130 rubber compound. Also, a method for diagnosing running wheels of conventional and modernized design was determined. The ZETLAB program was chosen as a program for signal registration and analysis. This program allows not only displaying the signal in real time with the possibility of scaling, but also allows you to digitize the signal with the possibility of further processing the results in various standards. Finding out the occurrence of a defect in wheels and rails is mainly carried out by two methods, when shock pulses appear and according to an increased background of vibration. In practice, there is a process of "dry" rolling friction, and this means that the method of shock pulses for diagnosing the condition of wheels and a rail track can be used only in some cases in the form of extreme wear of the friction pairs of a wheel and a rail. That is, the method of spectral analysis of fluctuations in the power of random vibration can be successfully applied to diagnose the state of the rail track and crane wheel.  The diagnostic method based on the overall vibration level allows for an overall assessment of the technical condition. Such diagnostics makes it possible to identify defects only at the very last stage of development, when they lead or have already led to partial destruction of the rolling surface of the wheel and the surface of the rail, that is, to an increase in the overall level of vibration. The performance evaluation criteria are fully focused on the corresponding standard vibration levels for the investigated friction pair. A friction pair is considered to be defective, the vibration of which exceeds the general standard. When determining an increased overall level of vibration, maintenance personnel must make a decision to replace parts or a unit to prolong its operation. The results obtained indicate the advisability of using the wheels of the modernized design on the cargo carriage of an overhead crane.

scholarly journals Instrumentation used for vibration monitoring on the supports of the tank scales of the port transshipment complex

2021 ◽  
Vol 2061 (1) ◽  
pp. 012021
Author(s):  
R G Dubrovin ◽  
N I Nikolaev ◽  
V V Gerasidi
Keyword(s):  
Metal Structure ◽  
Longitudinal Direction ◽  
Vibration Monitoring ◽  
Time Signal ◽  
Valve Mechanism ◽  
Resonant Frequencies ◽  
Metal Structures ◽  
Main Thing ◽  
A Chain ◽  
Vibration Measuring

Abstract The main thing for rotating equipment is to measure vibration, since, in the process of irreversible state change, a chain of defects always occurs and at least one of them significantly changes the vibration of the equipment. Using tank scales for static equipment, the vibration measuring makes it possible to determine the actual values of the levels and compare them with the maximum permissible values set by the manufacturer or regulatory documents. Also, the measurement of vibration levels in the time signal allows determining resonant frequencies at which vibration levels significantly increase due to the coincidence of the natural frequencies of the equipment with external workers, which can lead to increased loads on the supporting metal structures, suspended equipment and subsequently to fatigue destruction of the latter. Results of the work: the excess of the measured vibration levels on the supports of the hopper scales No. 28.1 was recorded by vibration acceleration in pt.11 (longitudinal direction) from twelve measurements; the excess of the measured vibration levels on the supports of the hopper scales No. 28.2 was not recorded, but increased levels of vibration speed were observed in pt. 11 and pt. 12; excessive vibration levels at the same measurement points on different scales may indicate that it is necessary to conduct a survey of the operation of the valve mechanism for smooth running and to monitor the condition of the metal structure under the fourth supports; it is recommended to perform a repeated measurement of the vibration of the hopper scales after inspection and repair of the structures of the scales.

scholarly journals Technical condition of welded load-bearing metal structures of operated agricultural hoisting cranes

2020 ◽  
Vol 175 ◽  
pp. 11005
Author(s):  
Alexander Scherbakov ◽  
Anna Babanina ◽  
Ivan Kochetkov ◽  
Pavel Khoroshilov
Keyword(s):  
Plastic Deformation ◽  
Metal Structure ◽  
Technical Condition ◽  
Technical Diagnostics ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Load Bearing ◽  
Metal Structures ◽  
Elastic Plastic ◽  
Alloy Steels

The paper considers the methodology for assessing the technical condition of welded load-bearing metal structures of operated agricultural hoisting cranes. In the course of the study, the relationship between structural, mechanical and magnetic parameters was established during cyclic elastic-plastic deformation of low-carbon and low alloy steels. Based on the analysis, it was concluded that the dependence of the minimum values of the magnetic parameter on the acting stresses Нр(σ) is influenced by the metal structure and its chemical composition. It has been established that the coarser-grained structure of the studied steels under elastic-plastic deformation contributes to a shift in the minimum values of Нр towards lower acting stresses; an increase in the strength characteristics of steels shifts the minimum of Нр toward large values of s, which must be taken into account when conducting technical diagnostics of the elements of the operating metal structures of hoisting cranes. Based on the results of the study, a method for determining the acting stresses in the elements of the metal structures of hoisting cranes was developed, which, by the nature and magnitude of the change in the residual magnetization of the scattering field during their stepwise loading (unloading), allows judging the magnitude of the acting stresses. The work also presents a methodology for assessing the technical condition of welded load-bearing metal structures of hoisting cranes based on the integrated use of passive flux-gate and other control methods, which allows determining the acting stresses used in strength calculations in the identified hazardous zones of concentration of stresses in the elements of metal structures.

scholarly journals The strength of welded structures at low climatic temperatures

2018 ◽  
Vol 245 ◽  
pp. 08001
Author(s):  
Sergey Sokolov ◽  
Ivan Vasilyev ◽  
Konstantin Manzhula
Keyword(s):  
Metal Structure ◽  
Welded Structures ◽  
Metal Structures ◽  
Steel 09G2s ◽  
Normative Documents ◽  
Selection Of

Methods for the selection of steels for metal structures were analyzed in accordance with the normative documents GOST 32578-2013, ISO 20332-2015 and F.E.M.1.001. As the example the choice of steel 09G2S was confirmed for a metal structure of a crane, operated at a temperature of minus 55° C. To confirm the correctness of the choice of steel for this design and justify the allowable size of defects, welded samples were tested at temperatures from plus 20 to minus 60° C.

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