Dynamic Loading of Synchronous Belts

2000 ◽  
Vol 124 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Tomas Johannesson ◽  
Martin Distner
Keyword(s):  
Experimental Data ◽  
Dynamic Loading ◽  
Dynamic Load ◽  
Coulomb Friction ◽  
Static Load ◽  
Belt Drives ◽  
History Effects ◽  
Timing Belt ◽  
Load Conditions ◽  
Good Agreement

In automotive timing belt drives friction history effects must be taken into concern due to rapidly changing loads. Here a spring based model capable of handling dynamic load conditions is presented. The model also covers partial meshing effects and utilizes Coulomb friction. The model shows good agreement with experimental data found in literature. It is proven that when simulating synchronous belt drives during rapidly changing load conditions, using models for quasi-static load conditions stepwise are not sufficient.

scholarly journals The deformability of the stress-strained concrete strips between the cracks during the short-term dynamic loading

2020 ◽  
Vol 315 ◽  
pp. 07002
Author(s):  
Zaur Galyautdinov ◽  
Oleg Kumpyak ◽  
Daud Galyautdinov
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Dynamic Loading ◽  
Experimental Research ◽  
Inclination Angle ◽  
Dynamic Load ◽  
Statistic Analysis ◽  
Theoretical Studies ◽  
Short Term ◽  
Experimental And Theoretical Studies

The formation of non-intersecting cracks in stress-strained ferroconcrete elements leads to separation of concrete strips between the cracks. The results of the experimental research indicate a significant decrease of the durability and deformability of the stress-strained concrete strips between cracks both under static and short-term dynamic loading. At the same time physico-mechanical properties depend on the straining deformations and rebars’ inclination angle towards the cracks. The existing theoretical and experimental results evaluate only the durability of the concrete strips between the cracks. The current paper presents the results of experimental and theoretical studies on the dynamic deformability of the stress-strained discs between the cracks. The statistic analysis of the experimental data is done; on the basis of the analysis we suggest the dependencies, characterizing the deformability of the concrete strips during the short-term dynamic load depending on the level of the straining deformations and rebars’ inclination angle towards the cracks.

scholarly journals EXPERIMENTAL STUDY OF PLATES FOR PUNCHING UNDER DYNAMIC LOADING

2021 ◽  
Vol 4 (4) ◽  
pp. 41-48
Author(s):  
N. Trekin ◽  
D. Sarkisov ◽  
V. Krylov ◽  
E. Evstaf'eva ◽  
K. Andryan
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Static Load ◽  
Dynamic Testing ◽  
Experimental Studies ◽  
Breaking Load ◽  
Technical Literature ◽  
Failure Patterns ◽  
Static And Dynamic Loading

the issues of strength and deformability of reinforced concrete floors during punching remain insufficiently studied at present, despite the available publications in the technical literature. This article presents the results of experimental studies on punching of fragments of conjugation of flat reinforced concrete monolithic slabs with a column under dynamic loading. The purpose of these studies was to obtain experimental data on the stress-strain state of a fragment of a monolithic floor during dynamic punching with varying thickness and class of concrete, to reveal the failure patterns of experimental samples, and to obtain new experimental data. A setup for dynamic testing is described. Comparison of breaking load for specimens tested under dynamic loading with breaking load for specimens tested for static load is presented. The angles of inclination of the punching shear pyramid under static and dynamic loading are indicated.

scholarly journals Experimental Study on Mechanical Properties of a Medium Size Box-Type Corrugated Steel Bridge

2021 ◽  
Author(s):  
Wenqiang Fu ◽  
Xinsha Fu ◽  
Yuting He ◽  
Baijian Li
Keyword(s):  
Mechanical Properties ◽  
Dynamic Load ◽  
Static Load ◽  
Design Method ◽  
Axial Stress ◽  
Structure Design ◽  
Steel Bridge ◽  
Maximum Value ◽  
Box Structure ◽  
Load Conditions

Different from an arch bridge, the load-carrying capacity of a box structure mainly depends on the bending capacity of corrugated steel. This paper explores the mechanical properties of a corrugated steel box bridge. The mechanical properties of a 13 m span corrugated steel box bridge under static and dynamic loads were tested. Three static load conditions were tested, and four dynamic load conditions were tested, including 20 km/h, 40 km/h, 60 km/h, and 80 km/h. Through the analysis of section strain, vault displacement, dynamic strain, and internal force, the following conclusions can be drawn: (1) when the static load changes from the right arch foot and vault to the left arch foot, the strain value of each measuring point continues to increase, which may be caused by the accumulation of deformation due to the adjustment of the stress state of the soil and corrugated steel caused by loading; (2) the displacement change in the test is more sensitive than the strain change; (3) the vault strain reaches the maximum value at a specific speed of 60 km/h. This is related to the structural resonance caused by vehicle operation, and the natural frequency of the corrugated steel box bridge can be determined by a field vehicle dynamic load test; (4) the damping value of an embedded corrugated steel bridge is large, and the energy dissipation capacity is strong, which is very beneficial to structural earthquake resistance and to reducing the structural resonance under traffic load; (5) the dynamic increasing strain coefficient is less than 1, which means that the strain caused by a dynamic load is far less than that caused by a static load, and it reaches the maximum value at a certain speed (60km/h); (6) the maximum bending stress and maximum axial stress of the corrugated steel box bridge tested in this paper are basically the same, which indicates that the axial stress of the box structure cannot be ignored. However, the box structure design method proposed in the CHBDC code does not consider the axial stress, so it is necessary to further improve the box structure design method; (7) most of the axial force of a box corrugated steel bridge is tensile force. The pavement structure layer has an effect on the overall performance of the corrugated steel box bridge, which is similar to the decompression plate: it makes the overall stress (I ∼ V section) more uniform and the bending moment smaller.

scholarly journals The modelling and introductions of new type ribs of lattice of the two cylinder of gin

2021 ◽  
Vol 273 ◽  
pp. 07020
Author(s):  
Shuhrat Azizov ◽  
Muhammadaminhon Ibrohimov ◽  
Farhod Uzoqov ◽  
Mirshoroffiddin Mirzakarimov
Keyword(s):  
Experimental Model ◽  
Dynamic Loading ◽  
Dynamic Load ◽  
Static Load ◽  
Lateral Displacement ◽  
Bending Vibrations ◽  
Single Chamber ◽  
New Type

Using the above data on the manufacture of grates and taking into consideration the bending vibrations of the saw cylinders and displacement of the grates under dynamic load. Taking into account the primary factors of sectional and individual grates ribs also in order to prevent cross-displacement of grates ribs. We modeled and introduced a new type of grates ribs for a single- chamber and two-cylinder gin, which is comprised of the top and bottom, grates ribs aligned with three brackets and tightening laths with a new type of fastening respectively. In the article, consider the simulated static load experimental model of a new grate ribs lattice, which allows eliminating lateral. Displacement of ribs at dynamic loading.

Transmission Error in Synchronous Belt Drives With Idler (Influence of Thickness Error of Belt Back Face Under No Load Conditions)

2004 ◽  
Vol 126 (1) ◽  
pp. 148-155 ◽  
Author(s):  
Kenichi Makita ◽  
Masanori Kagotani ◽  
Hiroyuki Ueda ◽  
Tomio Koyama
Keyword(s):  
Experimental Data ◽  
Transmission Error ◽  
Belt Drive ◽  
Analysis Method ◽  
Belt Drives ◽  
Back Face ◽  
Thickness Error ◽  
Synchronous Belt Drive ◽  
Load Conditions

Synchronous belt drives are commonly used in conjunction with an idler on the back face of the belt. However, thickness errors between the belt pitch line and back face of the belt, if present, will result in a change in belt tension on the span, and are considered to affect transmission error. In the present study, the transmission error in a synchronous belt drive with an idler under no load was investigated both theoretically and experimentally using a belt of known thickness error. The computed transmission error agrees well with the experimental data thereby verifying the applicability of the analysis method. In addition, a transmission error was mainly generated by the change in length of the belt pitch line due to the thickness error of the belt. It is shown that the transmission error due to the belt thickness error can be removed by using an automatic tensioner.

Experimental Determination of Dynamic Loading in a Drive Chain with Transverse Vibrations as a String with Fixed Ends

2020 ◽  
pp. 3-10 ◽  
Author(s):  
S.V. Palochkin ◽  
P.N. Rudovskiy
Keyword(s):  
Experimental Data ◽  
Dynamic Loading ◽  
Dynamic Load ◽  
Test Procedure ◽  
Dynamic Loads ◽  
Automated System ◽  
Tension Force ◽  
Machine Drive ◽  
Transverse Vibrations ◽  
A Chain

Chain transmissions are widely used in drives of hoisting-and-transport and ag-ricultural machines, as well as in a number of machine tools and technological equipment in various branches of industry. However, a significant disadvantage of these transmissions is the high vibration activity under high dynamic loading. In this regard, the study of dynamic loads that occur during chain vibrations and affect the operability of the machine drive is one of the essential tasks of its dynamics. The article presents experimental studies performed in order to determine the maximum dynamic loads in a chain transmission of a machine drive with transverse vibrations of the chain. The most common case of transverse vibrations of a chain loop is studied as a string with fixed ends. This type of vibration is typical of chain transmissions with large masses of sprockets and parts attached to them. The article presents a description of an original test bench with an automated system for collecting and processing experimental data and a test procedure. The obtained experimental data are presented in the form of tables and graphical dependences of the maximum dynamic loads on the tension force of the chain average per cycle of vibrations and the amplitude of its transverse vibrations in the center of the span, related to its length. As a result of approximation of the experimental data array, an empirical formula is proposed that can be used in dynamic calculations of the drive. It is established that the maximum dynamic load and its amplitude increases with the increase of the ratio of the amplitude of transverse vibrations of the chain in the middle of its span to its length and the initial tension force of the chain. The ratio of the dynamic load amplitude to the tension force of the chain decreases with the increase of the latter.

Frequency Effects on the TEHD Behavior of a Tilting-Pad Journal Bearing Under Dynamic Loading

1999 ◽  
Vol 121 (2) ◽  
pp. 321-326 ◽  
Author(s):  
P. Monmousseau ◽  
M. Fillon
Keyword(s):  
Dynamic Loading ◽  
Dynamic Load ◽  
Critical Frequency ◽  
Static Load ◽  
Journal Bearing ◽  
Loading Frequency ◽  
Tilting Pad ◽  
High Dynamic ◽  
Tilting Pad Journal Bearing ◽  
Rotating Load

In this paper, a theoretical nonlinear analysis of a tilting-pad journal bearing is presented when both a dynamic load and a static load are applied. This analysis is performed under TEHD regime which takes into account both thermal behavior and elastic deformations of the bearing. A comparison between numerical maximum journal amplitudes and experimental data in the case of synchronous dynamic loading is carried out in order to justify the TEHD analysis. The influence of the dynamic loading frequency, which can occur because of vibrations in a turbomachinery, will be studied at a constant rotational speed (15,000 rpm) and for a low (200 N) and a high (2652 N) rotating load and for a periodic dynamic load. It will be shown that, for a critical frequency, the amplitude of the shaft orbit is maximum and this changes the behavior of the tilting-pad journal bearing. It is apparent that the application of the dynamic load generates a thermal transient regime. The increase in the maximum bearing temperature is larger for high dynamic loading response. Consequently, the behavior of the bearing is mainly modified during the first few seconds when the loading frequency is near the critical frequency.

scholarly journals About the Criteria for the Choice of Materials to Protect Against the Mechanical Dynamic Loading

2021 ◽  
Vol 47 (4) ◽  
pp. 281-288
Author(s):  
V. Ya. Shevchenko ◽  
A. S. Oryshchenko ◽  
S. N. Perevislov ◽  
M. V. Sil’nikov
Keyword(s):  
Experimental Data ◽  
Dynamic Loading ◽  
Ceramic Materials ◽  
Physical Principle ◽  
Total Energies ◽  
Selection Of ◽  
Good Agreement

Abstract A criterion for the selection of materials to protect against the mechanical dynamic loading is proposed and substantiated. The mechanisms of the fracture of brittle ceramic materials that are widely used in structures that prevent penetration and are very common in practice are discussed. Unlike other estimates, the proposed formula is based on the physical principle of comparing the total energies of loading and obstacles, and is in good agreement with the experimental data.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

Predicting the Effect of Tire Tread Pattern Design on Thick Film Wet Traction

1977 ◽  
Vol 5 (1) ◽  
pp. 6-28 ◽  
Author(s):  
A. L. Browne
Keyword(s):  
Experimental Data ◽  
Network Design ◽  
Thick Film ◽  
Digital Computer ◽  
Analytical Tool ◽  
Design Practice ◽  
Pattern Design ◽  
Performance Results ◽  
Good Agreement

Abstract An analytical tool is presented for the prediction of the effects of changes in tread pattern design on thick film wet traction performance. Results are reported for studies in which the analysis, implemented on a digital computer, was used to determine the effect of different tread geometry features, among these being the number, width, and lateral spacing of longitudinal grooves and the angle of zigzags in longitudinal grooves, on thick film wet traction. These results are shown to be in good agreement with experimental data appearing in the literature and are used to formulate guidelines for tread groove network design practice.

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