scholarly journals A relationship between friction plate roughness and the external friction angle of wheat kernels

2017 ◽  
Vol 20 (sup3) ◽  
pp. S2409-S2417 ◽  
Author(s):  
Zdzisław Kaliniewicz ◽  
Zbigniew Żuk
Author(s):  
Zdzisław Kaliniewicz ◽  
◽  
Andrzej Anders ◽  
Krzysztof Jadwisieńczak ◽  
Piotr Markowski ◽  
...  

Author(s):  
Zdzisław Kaliniewicz ◽  
Zbigniew Żuk ◽  
Zbigniew Krzysiak

The aim of this study was to determine the correlation between the external friction angle of cereal kernels and the roughness of a steel friction plate. The experiment was performed on the kernels of five principal cereals: wheat, rye, barley, oats and triticale. Flat seed units composed of three spaced kernels joined by adhesive tape were analyzed in each experimental variant. The external friction angle of flat seed units was determined on 9 steel friction plates with different roughness. Measurements were performed in 3 replications with a photosensor device which registered the external friction angle of cereal kernels. On friction plates with surface roughness Ra=0.36 to Ra=6.72, the average values of the angle of external friction ranged from 17.56° in rye kernels to 34.01° in oat kernels. The greatest similarities in the angle of external friction were observed between wheat and triticale kernels, whereas the greatest differences were noted between barley and oat kernels and between barley and triticale kernels. Friction plates made of ST3S steel should be characterized by the lowest surface roughness to minimize energy consumption during grain processing. The optimal surface roughness of steel friction plates was determined at Ra=0.9.


Author(s):  
Zdzisław Kaliniewicz ◽  
Zbigniew Żuk ◽  
Zbigniew Krzysiak

The aim of this study was to determine the correlation between the external friction angle of cereal kernels and the roughness of a steel friction plate. The experiment was performed on the kernels of five principal cereals: wheat, rye, barley, oats and triticale. Flat seed units composed of three spaced kernels joined by adhesive tape were analyzed in each experimental variant. The external friction angle of flat seed units was determined on 9 steel friction plates with different roughness. Measurements were performed in 3 replications with a photosensor device which registered the external friction angle of cereal kernels. On friction plates with surface roughness Ra=0.36 to Ra=6.72, the average values of the angle of external friction ranged from 17.56° in rye kernels to 34.01° in oat kernels. The greatest similarities in the angle of external friction were observed between wheat and triticale kernels, whereas the greatest differences were noted between barley and oat kernels and between barley and triticale kernels. Friction plates made of ST3S steel should be characterized by the lowest surface roughness to minimize energy consumption during grain processing. The optimal surface roughness of steel friction plates was determined at Ra=0.9.


Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 45-50 ◽  
Author(s):  
Stanisław KONOPKA ◽  
Ewelina KOLANKOWSKA

One of the most popular methods of determining the coefficient of kinetic friction between a pair of solid objects involves an inclined plane. However, manual measurements of the time taken by a particle to travel a certain distance (usually performed with a stopwatch) and the angle of an inclined plane (on a scale) are not always highly accurate or precise. The coefficient of kinetic friction has to be determined on the assumption that a particle moves in uniformly accelerated motion. The aim of this study was to analyse particles moving in uniformly accelerated motion on an inclined plane and to modify the method of measuring movement parameters. A mechatronic measuring device and a high-speed camera were used to monitor the movement of wheat kernels on a steel friction plate. The experimental variables were the distance between photosensors (length of the measured section) and the kernel’s position relative to the direction of movement. An analysis of the mean values of time taken by particles to travel different distances revealed that the particles were not moving in uniformly accelerated motion. The results indicate that the coefficient of kinetic friction of irregularly shaped particles cannot be determined reliably on an inclined plane. Several recommendations for modifying the test stand were proposed.


2021 ◽  
Vol 13 (15) ◽  
pp. 8201
Author(s):  
Lihua Li ◽  
Han Yan ◽  
Henglin Xiao ◽  
Wentao Li ◽  
Zhangshuai Geng

It is well known that geomembranes frequently and easily fail at the seams, which has been a ubiquitous problem in various applications. To avoid the failure of geomembrane at the seams, photocuring was carried out with 1~5% photoinitiator and 2% carbon black powder. This geomembrane can be sprayed and cured on the soil surface. The obtained geomembrane was then used as a barrier, separator, or reinforcement. In this study, the direct shear tests were carried out with the aim to investigate the interfacial characteristics of photocured geomembrane–clay/sand. The results show that a 2% photoinitiator has a significant effect on the impermeable layer for the photocured geomembrane–clay interface. As for the photocured geomembrane–sand interface, it is reasonable to choose a geomembrane made from a 4% photoinitiator at the boundary of the drainage layer and the impermeable layer in the landfill. In the cover system, it is reasonable to choose a 5% photoinitiator geomembrane. Moreover, as for the interface between the photocurable geomembrane and clay/sand, the friction coefficient increases initially and decreases afterward with the increase of normal stress. Furthermore, the friction angle of the interface between photocurable geomembrane and sand is larger than that of the photocurable geomembrane–clay interface. In other words, the interface between photocurable geomembrane and sand has better shear and tensile crack resistance.


Author(s):  
Seung-Jae Lee ◽  
Tae-Sung Eom ◽  
Eunjong Yu

AbstractThis study analytically investigated the behavior of reinforced concrete frames with masonry infills. For the analysis, VecTor2, a nonlinear finite element analysis program that implements the Modified Compression Field Theory and Disturbed Stress Field Model, was used. To account for the slip behavior at the mortar joints in the masonry element, the hyperbolic Mohr–Coulomb yield criterion, defined as a function of cohesion and friction angle, was used. The analysis results showed that the lateral resistance and failure mode of the infilled frames were significantly affected by the thickness of the masonry infill, cohesion on the mortar joint–brick interface, and poor mortar filling (or gap) on the masonry boundary under the beam. Diagonal strut actions developed along two or three load paths on the mortar infill, including the backstay actions near the tension column and push-down actions near the compression columns. Such backstay and push-down actions increased the axial and shear forces of columns, and ultimately affect the strength, ductility, and failure mode of the infilled frames.


2021 ◽  
Vol 208 ◽  
pp. 176-185
Author(s):  
Xiaojing Yang ◽  
Min Guo ◽  
Qiongshuai Lyu ◽  
Miao Ma

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