scholarly journals Unbalanced Vibration Identification of Tangential Threshing Cylinder Induced by Rice Threshing Process

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Zhong Tang ◽  
Haotian Zhang ◽  
Yuepeng Zhou

Unbalanced vibration of tangential threshing cylinder increased the grain loss, shortened service life of the cylinder, and resulted in structural resonance during the rice threshing process. In this paper, the vibration amplitude and frequency of tangential threshing cylinder shaft were tested, and the vibration state of tangential threshing cylinder was identified. The restricted and working modalities of tangential threshing cylinder were solved by ANSYS software. Then, by comparing the resonance phenomenon between the inherent constraint frequency and the rotation speed frequency, the shaft vibration under the idle condition of tangential threshing cylinder was tested and analyzed. According to the axial vibration and axial trajectory of the cylinder, the inherent properties and characteristics of unbalanced vibration were revealed. Test results showed that when the tangential threshing cylinder was at idling and no-load state, the amplitude of vibration in the feed direction of straw flow was -0.049~0.060 mm, and the average vibration amplitude was 0.013 mm. As rice flowed along the tangential threshing cylinder, the vibration amplitude slightly increased. The trend and phase of each trajectory were similar, although the amplitude of each trajectory was different. The tangential threshing cylinder axis trajectory was flat oval. Unbalanced vibration was induced by the rice stalks in the concave gap.

2015 ◽  
Vol 749 ◽  
pp. 278-281
Author(s):  
Jia Horng Lin ◽  
Jing Chzi Hsieh ◽  
Jin Mao Chen ◽  
Wen Hao Hsing ◽  
Hsueh Jen Tan ◽  
...  

Geotextiles are made of polymers, and their conjunction with different processes and materials can provide geotextiles with desirable characteristics and functions, such as filtration, separation, and drainage, and thereby meets the environmental requirements. Chemical resistant and mechanical strong polymers, including polyester (PET) and polypropylene (PP), are thus used to prolong the service life of the products made by such materials. This study proposes highly air permeable geotextiles that are made with different thicknesses and various needle punching speeds, and the influences of these two variables over the pore structure and mechanical properties are then examined. PET fibers, PP fibers, and recycled Kevlar fibers are blended, followed by being needle punched with differing spaces and speeds to form geotextiles with various thicknesses and porosities. The textiles are then evaluated for their mechanical strength and porosity. The test results show that a thickness of 4.5 cm and 1.5 cm demonstrate an influence on the tensile strength of the geotextiles, which is ascribed to the webs that are incompletely needle punched. However, the excessive needle punching speed corresponding to a thickness of 0.2 cm results in a decrease in tensile strength, but there is also an increase in the porosity of the geotextiles.


2020 ◽  
pp. 21-25
Author(s):  
Janusz Lewandowski ◽  
Dariusz Rozumek

The paper presents test results concerning the service life of fillet welds made in steel S355. In addition, the article discusses the initiation and growth of fatigue cracks in specimens subjected to bending with torsion. The tests were performed in relation to constant stress ratio R = -1 and 0. The results presented in the article take into account the effect of the technological treatment on the service life of the specimens. The tests revealed longer service life of the specimens not subjected to the technological treatment, both when R = -1 and 0.


2014 ◽  
Vol 89 (11) ◽  
pp. 2578-2587 ◽  
Author(s):  
Seong-Lok Hong ◽  
Jong-Dae Kong ◽  
Yaung-Soo Kim ◽  
Dae-Young Eom ◽  
Byung-Ju Park ◽  
...  

2014 ◽  
Vol 590 ◽  
pp. 312-315
Author(s):  
Wei Hong Xuan ◽  
Pan Xiu Wang ◽  
Yu Zhi Chen ◽  
Xiao Hong Chen

The dry shrinkage deformation of polypropylene fiber mortar was analyzed by ANSYS software and compared with experiment value in this paper. The error of the calculated and experimental results in the 14 days and 28 days are 7.8% and 10.5%. It can be found that the calculated results are in good agreement with test results. The results indicate that the dry shrinkage value of polypropylene fiber mortar is lower than ordinary mortar. Adding polypropylene fibers can inhibit the process of cracking and improve the fracture toughness of cement-based materials.


2014 ◽  
Vol 687-691 ◽  
pp. 232-235
Author(s):  
Tao Sun ◽  
Xiao Qing Zhou ◽  
Zhuo Chen ◽  
Fang Li

Heat pipe has excellent conductivity of heat and diversity of structure, so it can be used in machining which can decrease or avoid using the cutting fluid. In this paper, the abrasive tool with rotating heat pipe was designed. To validate that the abrasive tool with heat pipe can safely and steadily grind materials, the model analysis of abrasive tool with heat pipe is carried on with the ANSYS software based on the theory of modal analysis, then the first five order natural frequency and vibration models are to get. The results indicated that the vibrational frequency of designed abrasive tool is far away from natural frequency, so resonance phenomenon does not happen and the abrasive tool with heat pipe can smoothly work.


2011 ◽  
Vol 339 ◽  
pp. 444-447
Author(s):  
Qiu Yi Chu ◽  
Guo Ying Meng ◽  
Xun Fan

Deviated belt will cause great harm, which will not only reduce its service life, but also will lead to the machine damage and personal casualty. This paper analyzes the reasons for belt deviation and establishes the mechanical model of a conveyor belt. The theoretical analysis and numerical simulation are adopted in this article to analyze and research the speed when the belt is deviated, obtain the relation between the transversal movement speed of belt and front offset angle of a idler, idler rotation speed and belt speed, and provide the deviation correction and prevention of belt conveyor with theoretical guidance.


2021 ◽  
Vol 23 (3) ◽  
pp. 405-412
Author(s):  
Andrzej Gajek ◽  
Adam Kot ◽  
Piotr Strzępek

The paper presents the proposals of extension of the periodic tests of the selected ESP system sensors: angular velocity sensor and lateral acceleration sensor using a universal diagnostics tester and a plate stand (a wheel play detector unit). The idea of this approach is to evaluate the signals from the above sensors in terms of their amplitude and frequency in the case of known forcing at the plate stand. Knowledge of the amplitude and frequency of the plates excitation and the model of tested vehicle allows for predicting the response of vehicle. On this way the verification of sensors indications is possible. This article presents the flat model of a vehicle placed on the plate stand, simulation tests and the results of its validation for three different vehicles. The results of the investigation show that the wheelbase of vehicle has a significant impact on the steady-state vibration amplitude. This conclusion is important in the practical application of this method to test the vehicle yaw rate sensor in the ESP system.


2019 ◽  
pp. 62-71
Author(s):  
Петр Александрович Фомичев ◽  
Игорь Михайлович Сила

The technique of processing the test results to the destruction of samples cut from slings and dome fabric after prolonged use or storage of the parachute is described. The normal law of load distribution before failure is adopted.It is proposed to find the minimum breaking load as the lower confidence limit depending on the number of tested samples and a confidence probability of 0.99.The results of strength tests of samples from the parachutes of the landing D-5 series 2 of 1983, the spare Z-5 of 1984, and the rescue S-5K series 2 of 1989 are presented.A total of 301 samples were tested, including 54 samples from slings D-5, 48 samples from slings Z-5 and S-5K, samples from fabrics of domes on the base and weft. Samples from slings were cut out at the edge of the dome, in the middle, at the arc buckles.Fabric samples were cut radially from the top to the edge of the dome. The dependence of the strength characteristics on the location of the samples along the length of the slings or the dome panel has not been established.There are no gross errors in the tests according to the Grubbs criterion.The strength degradation coefficients of the slings and fabrics of the domes are determined as the ratio of the breaking load after long-term operation or storage to the initial values adopted during the design.The proximity of the degradation coefficients of slings and dome fabrics was noted. Based on the set of test results in order to obtain the minimum values of the degradation coefficients, a linear dependence on the life of the parachute is established.This period should be counted from the year the parachute was made.The dependence of the minimum degradation coefficients (maximum degradation) on the service life makes it possible to assess the drop in the strength characteristics of the structural elements with increasing service life. This dependence allows you to predict the maximum allowable landing speed when deciding on the extension of the life of the parachute.


2021 ◽  
Vol 264 ◽  
pp. 04081
Author(s):  
Oybek Ishnazarov ◽  
Abdusaid Isakov ◽  
Utkir Islomov ◽  
Umirzoq Xoliyorov ◽  
Dilshod Ochilov

The article presents the possibility of increasing the service life of pumping units. Particular attention is paid to the regulation of the speed of rotation of the pumping unit. There are some assumptions in the mathematical model that do not affect the final result. The factors influencing the operating mode are given. It is indicated that the speed of rotation of the pump shaft significantly affects the wear resistance of the pump blades. Thus, the regulation of the pump rotation speed will rationally increase its service life.


2021 ◽  
Vol 3 (1) ◽  
pp. 037-042
Author(s):  
V. O. KROPOTIN ◽  
◽  
S. S. GIRSHIN ◽  
V. N. GORYUNOV ◽  
E. V. PETROVA ◽  
...  

With the expansion of the electric power system, the number of distribution plants increases, the most common in which are oil-immersed transformers. the increase in the number of transformers leads to an increase in energy losses, which depend on many factors, including the temperature of the windings. at the same time, temperature is one of the most important parameters that determine the service life of a transformer. the paper discusses a digital model of the thermal regime of an oil-immersed transformer with natural cooling based on the ansys software, focused both on the tasks of calculating energy losses and on assessing the load capacity. the simulation results are compared with the heating rates. the use of thermal regime models when calculating power losses can significantly increase the accuracy of calculations.


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