scholarly journals Contribution to the analysis of the frame stiffness of the cranes with loading-unloading trolley

2020 ◽  
Vol 26 (4) ◽  
pp. 109-114
Author(s):  
Milomir Gašić ◽  
Mile Savković ◽  
Nebojša Zdravković ◽  
Goran Marković
Keyword(s):  
Calculation Model ◽  
Optimal Structure ◽  
Geometrical Parameters ◽  
Supporting Surface ◽  
Transverse Stiffness ◽  
Radial Bearing ◽  
Geometric Size ◽  
Frame Stiffness

The paper analyzes the dependence of the stiffness of the support frames of the cranes with loading-unloading trolley on the change of geometrical parameters of the frames. The calculation model of the frames with transverse stiffness was formed because it additionally stiffens the supporting surface of the frames for connection with the axial-radial bearing. The relations of characteristic geometrical sizes of longitudinal and transverse elements were established, at which the necessary stiffness of the frames of loading-unloading trolley was achieved. Also, the variables and constants of geometric size were introduced, as well as the constant values of appropriate coefficients, the variation of which provides the possibility to form the optimal structure of the frames of loading-unloading trolley.

A configuration interaction study of the ground and first excited 1∑+ states of the NaI molecule

1992 ◽  
Vol 70 (2) ◽  
pp. 309-313 ◽  
Author(s):  
Yoshiko Sakai ◽  
Eisaku Miyoshi ◽  
Tosinobu Anno
Keyword(s):  
Excited State ◽  
Potential Method ◽  
Model Potential ◽  
Calculation Model ◽  
Geometrical Parameters ◽  
Interaction Study ◽  
Avoided Crossing ◽  
Wide Range ◽  
Doubly Excited ◽  
First Excited State

Multireference singly and doubly excited CI (MRSDCI) calculations are performed on the NaI molecule by using a model potential method. The potential energy curves of the ground and first excited 1∑+ states are generated over a wide range of internuclear distance R. The curves yield the avoided crossing, which is expected to arise by the mixing of the ionic and covalent configurations, and thus the curve of the first excited state shows a shallow minimum. The geometrical parameters, dipole moment, and dissociation energy are calculated. The agreement of those with the experimental results is satisfactory. Keywords: NaI, MRSDCI calculation, model potential method, potential curve, excited state.

Study on the Influence of Geometrical Parameters of Abrasive Grains in Abrasive Flow Machining

2010 ◽  
Vol 135 ◽  
pp. 52-57
Author(s):  
Zhong Ming Xu ◽  
Yong Wu Luo
Keyword(s):  
Cone Angle ◽  
Calculation Model ◽  
Geometrical Parameters ◽  
Cutting Depth ◽  
Abrasive Flow Machining ◽  
Abrasive Grains ◽  
Smooth Flow ◽  
Quantitative Calculation ◽  
Maximum Value ◽  
Geometrical Shapes

In order to improve the accuracy of quantitative calculation of abrasive flow machining, the influence of geometrical parameters of abrasive grains on machining is analyzed by representing the geometrical shapes of abrasive grains with three parameters, namely height of abrasive grains, cone angle and wear height, establishing the calculation model of blunt conical abrasive grains for abrasive flow machining, deducing the force formulas of abrasive grains and calculating the maximum cutting depth in the event of smooth flow of abrasive grains in the boundary layer. It is shown by researches that the geometrical parameters of abrasive grains have significant influence on the maximum cutting depth as follows: The maximum cutting depth of abrasive grains increases linearly with the increase of height of abrasive grains, and varies in the form of hump with the changes of cone angle, the cutting depth has the maximum value when the cone angle reaches 60°; The maximum cutting depth of abrasive grains decreases rapidly with the increases of wear height, when the wear height increases to a critical value, the abrasive grains basically lose cutting ability.

VIBRATION ATTENUATION AT ASYMMETRIC CROSS‐FORM JOINTS OF BUILDINGS

2005 ◽  
Vol 11 (2) ◽  
pp. 129-135
Author(s):  
Vytautas J. Stauskis ◽  
Marius Mickaitis
Keyword(s):  
Theoretical Calculation ◽  
Material Properties ◽  
Transmission Loss ◽  
Calculation Model ◽  
Geometrical Parameters ◽  
System Of Equations ◽  
Sound Energy ◽  
Vibration Attenuation ◽  
Structural Connections ◽  
Simplified Calculation

The aim of the work is to estimate sound energy transmission through asymmetrical cross‐junctions in buildings. Several kinds of these joints have been investigated. Theoretical calculation model to obtain transmission loss was developed and a system of equations established. The equations were solved and expressions were obtained for predicting transmission loss. Using this procedure for different structural connections, the simplified calculation formulas were received for different cases of asymmetrical cross‐joint. The influence of geometrical parameters and material properties were determined for the sound energy attenuation in the joints of buildings. The obtained results may be applied for evaluation of influence flanking noise transmission through different asymmetric cross‐junctions in buildings.

scholarly journals Mathematical calculation model for geometrical parameters of timber mesh design with orthogonal grid

Vestnik MGSU ◽  
2014 ◽  
pp. 60-69
Author(s):  
D. A. Loktev ◽  
I. S. Inzhutov ◽  
N. I. Lyakh ◽  
V. I. Zhadanov ◽  
V. N. Ermolin
Keyword(s):  
Calculation Model ◽  
Geometrical Parameters ◽  
Orthogonal Grid ◽  
Mathematical Calculation

scholarly journals INTERACTION RESEARCH INTO CONNECTION BETWEEN THREADED STEEL ROD AND GLULAM

2011 ◽  
Vol 3 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Tomas Gečys ◽  
Kęstutis Gurkšnys ◽  
Konstantin Rasiulis
Keyword(s):  
Bearing Capacity ◽  
Carrying Capacity ◽  
Calculation Model ◽  
Experimental Results ◽  
Geometrical Parameters ◽  
Manufacturing Defects ◽  
Diameter Hole ◽  
Steel Bar ◽  
Steel Bars ◽  
Adequate Margin

The article discusses the main methods for steel threaded rods pasted into timber. Single – threaded steel rod carrying capacity glued onto glulam (timber cross section – 100 x 100 mm, threaded rod – M12 and M16) has been experimentally determined. Behaviour based on the experimental results of two different methods for pasting rods into timber has been summarized: the first threaded steel rod was glued into 4 mm bigger diameter hole while the second – rod chased into 2 mm smaller diameter hole. The conducted experiment used 800 mm length glulam beams; threaded steel rods were glued to both ends of specimens (equal theoretical carrying capacity). The experiment in the tension of both ends was carried out. The obtained results were compared with theoretical expressions submitted in EC 5 – 1 – 1:2005 and STR 2.05.07:2005. The main dependences of geometrical parameters and carrying capacity have been provided. The main collapse forms of specimens and manufacturing defects having influence on the final carrying capacity and behaviour of the joint have been observed. Using the first method, a failure in the pasted rod occurs suddenly when timber splits along the fibre; in the second case, a failure is plastic when timber is compressed under thread. Additional experiments must be carried out using the first technology increasing the class of the strength of the pasted rod as under the maximum length of paste, in all cases, failure in the pasted rod occurred when a steel bar cracked. Along with an increase in the diameter of the rod, the dispersion of the results of the affixed slender part is increasing. Maximum variation in the results of applying the first method is 10%, whereas the second method of attaching makes 50%. Compared to the first method of attaching, the results of theoretical bearing capacity indicate that tests have an adequate margin which is equal to or is more than 2,0. A comparison of the second method of attaching results to theoretical bearing capacity makes clear that the experimental results of the tests have too low safety factor and in some cases are less than 1.0. This is due to the fact that the counting of attaching technology in some cases must be based on local compressed timber strength. The experimental study of two different methods for attaching steel bars reveals that the first method can be used in design practice considering both documents STR 2.05.07:2005 and EC 5-1-1:2005. The second method of attaching must be developed to ensure smooth rod surface coating adhesive. Attaching the second method should also be created in the exact form corresponding to the disintegration of the calculation model.

Bulk drag coefficient of a subaquatic vegetation subjected to irregular waves: Influence of Reynolds and Keulegan-Carpenter numbers

2020 ◽  
pp. 34-42
Author(s):  
Thibault Chastel ◽  
Kevin Botten ◽  
Nathalie Durand ◽  
Nicole Goutal
Keyword(s):  
Drag Coefficient ◽  
Wave Height ◽  
Wave Attenuation ◽  
Empirical Relationship ◽  
Breaking Waves ◽  
Irregular Waves ◽  
Geometrical Parameters ◽  
Flume Experiments ◽  
Seagrass Meadows ◽  
Artificial Vegetation

Seagrass meadows are essential for protection of coastal erosion by damping wave and stabilizing the seabed. Seagrass are considered as a source of water resistance which modifies strongly the wave dynamics. As a part of EDF R & D seagrass restoration project in the Berre lagoon, we quantify the wave attenuation due to artificial vegetation distributed in a flume. Experiments have been conducted at Saint-Venant Hydraulics Laboratory wave flume (Chatou, France). We measure the wave damping with 13 resistive waves gauges along a distance L = 22.5 m for the “low” density and L = 12.15 m for the “high” density of vegetation mimics. A JONSWAP spectrum is used for the generation of irregular waves with significant wave height Hs ranging from 0.10 to 0.23 m and peak period Tp ranging from 1 to 3 s. Artificial vegetation is a model of Posidonia oceanica seagrass species represented by slightly flexible polypropylene shoots with 8 artificial leaves of 0.28 and 0.16 m height. Different hydrodynamics conditions (Hs, Tp, water depth hw) and geometrical parameters (submergence ratio α, shoot density N) have been tested to see their influence on wave attenuation. For a high submergence ratio (typically 0.7), the wave attenuation can reach 67% of the incident wave height whereas for a low submergence ratio (< 0.2) the wave attenuation is negligible. From each experiment, a bulk drag coefficient has been extracted following the energy dissipation model for irregular non-breaking waves developed by Mendez and Losada (2004). This model, based on the assumption that the energy loss over the species meadow is essentially due to the drag force, takes into account both wave and vegetation parameter. Finally, we found an empirical relationship for Cd depending on 2 dimensionless parameters: the Reynolds and Keulegan-Carpenter numbers. These relationships are compared with other similar studies.

A fuzzy neural network approach for modeling the growth kinetics of FeB and Fe2B layers during the boronizing process

2018 ◽  
Vol 106 (6) ◽  
pp. 603 ◽  
Author(s):  
Bendaoud Mebarek ◽  
Mourad Keddam
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Fuzzy Neural Network ◽  
Treatment Time ◽  
Calculation Model ◽  
Average Error ◽  
Network Approach ◽  
Neural Network Approach ◽  
Fuzzy Neural ◽  
Kinetics Of

In this paper, we develop a boronizing process simulation model based on fuzzy neural network (FNN) approach for estimating the thickness of the FeB and Fe2B layers. The model represents a synthesis of two artificial intelligence techniques; the fuzzy logic and the neural network. Characteristics of the fuzzy neural network approach for the modelling of boronizing process are presented in this study. In order to validate the results of our calculation model, we have used the learning base of experimental data of the powder-pack boronizing of Fe-15Cr alloy in the temperature range from 800 to 1050 °C and for a treatment time ranging from 0.5 to 12 h. The obtained results show that it is possible to estimate the influence of different process parameters. Comparing the results obtained by the artificial neural network to experimental data, the average error generated from the fuzzy neural network was 3% for the FeB layer and 3.5% for the Fe2B layer. The results obtained from the fuzzy neural network approach are in agreement with the experimental data. Finally, the utilization of fuzzy neural network approach is well adapted for the boronizing kinetics of Fe-15Cr alloy.

Study of the process of forming a hole for a thread at manufacturing a high nut

2020 ◽  
Vol 76 (8) ◽  
pp. 841-846
Author(s):  
I. G. Shubin ◽  
A. A. Kurkin
Keyword(s):  
Metal Flow ◽  
Nonlinear Dependence ◽  
Geometrical Parameters ◽  
Relative Height ◽  
Forming Process ◽  
Normal Height ◽  
Accuracy Class ◽  
Limit Values ◽  
Program Complex ◽  
Class B

During manufacturing nuts of increased height, a problem of obtaining correct cylindrical form of the hole for thread and overall geometrical parameters arises. To solve the problem it is necessary to know regularity of the blank forming process. Results of the study of a technological process of high hexahedral nuts forming presented. The nuts were M18 of 22 mm height, M16 of 19 mm height and M12 of normal height 10 mm according to GOST 5915–70, accuracy class B, steel grade 10 according to GOST 10702–78. The volumetric stamping was accomplished at the five-position automatic presses of АА1822 type. It was determined, that unevenness of the metal flow in the process of plastic deformation of blanks of increased height nuts was caused by different stress conditions by their sections. To simulate the mode of deformation, the program complex QForm-3D was chosen. The complex ensured to forecast with necessary accuracy the metal flow in a blank, as well as to define the deformation force and arising stress in the working instrument. The simulation showed the presence of regularity between preliminary formed buffle and deviation of dimensions and form of a blank wall after its finishing piercing, which can be expressed by a nonlinear dependence. The limit values of the relative height of the buffle С/D = 0.56–0.588 defined, exceeding which will result in rejection of the finished product. Accounting the limit values of the relative height of the buffle will enable to correct a mode of technological operations and technological instruments at stamping of high hexahedral nuts.

Optimal structure of coal production for TPP of Ukraine regarding imports

2015 ◽  
Vol 2015 (3) ◽  
pp. 13-16 ◽  
Author(s):  
M.M. Makortetskiy ◽  
◽  
M.O. Perov ◽  
I.Yu. Novitsky ◽  
◽  
...  
Keyword(s):  
Optimal Structure ◽  
Coal Production
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