Determination of soil properties for site evaluation and dynamic analysis in Santiago. 1F, 3T, 10R

Mechanika ◽  
2021 ◽  
Vol 27 (3) ◽  
pp. 237-243
Author(s):  
Tadas ASTRAUSKAS ◽  
Michail SAMOFALOV

In the paper, it is proposed to cover by a mobile moving facility the shipyard open site, in Klaipeda, Lithuania (the EU). The facility of 40 m span consists of transversal frames, which are arranged by the step of 6.0 m, and a system of braces. Two types of steel frames have been considered: trussed and continuous. The actions are specified according to the design codes (Eurocode 3) and climatological data. In dynamic analysis, the longitudinal direction is defined for an inertia action, simulating braking. For calculating, a special algorithm of three stages has been prepared. At the first stage, three calculation schemes of one transversal frame were created. For the proposed schemes of the mobile moving facility, the calculation of only a transversal frame is effective in the preliminary determination of the cross-sectional areas and of the total structural weight. At the second stage, the frames were joined by braces. A preliminary comparison of the calculation results of the models was carried out after the first and second stages of the analysis. At the third stage, the dynamic analysis was performed and the influence of the dynamic impact was estimated. Finally, we compared the calculation results of three different FEM models and chose the most appropriate one. To sum up the investigations, conclusions and recommendations are presented.


2021 ◽  
Vol 36 ◽  
pp. 03014
Author(s):  
I.V. Komissarova ◽  
A.V. Chelovechkova ◽  
N.V. Miroshnichenko

Water-physical properties of soils are a set of soil properties that determine the accumulation, preservation and water transfer in the soil stratum. One of the important indicators of water-physical properties are soil-hydrological constants. These indicators can be used in forecasting yield, calculating the irrigation rate. The determination of soil-hydrological constants is a rather laborious process. In this article, we propose to obtain soil-hydrological constants from the data of the main hydrophysical characteristics. This technique allows to analyze the data and obtain soil-hydrological constants from the data of granulometric composition. The conducted studies have shown that the use of uncontrolled irrigation has led to the transformation of water-physical properties, the content of easily mobile, productive and gravitational moisture has decreased. When modeling the MHC curve, a change in the shape on the graphs can be noted.


Author(s):  
Jian-Qing Zhang ◽  
Ting-Li Yang

Abstract This work presents a new method for kinetostatic analysis and dynamic analysis of complex planar mechanisms, i.e. the ordered single-opened-chains method. This method makes use of the ordered single-opened chains (in short, SOC,) along with the properties of SOC, and the network constraints relationship between SOC,. By this method, any planar complex mechanism can be automatically decomposed into a series of the ordered single-opened chains and the optimal structural decomposition route (s) can be automatically selected for dynamic analysis, the paper present the dynamic equation which can be used to solve both the kinetostatic problem and the general dynamic problem. The main advantage of the proposed approach is the possibility to reduce the number of equations to be solved simultaneously to the minimum, and its high automation as well. The other advantage is the simplification of the determination of the coefficients in the equations, and thus it maybe result in a much less time-consuming algorthem. The proposed approach is illustrated with three examples. The presented method can be easily extended to the dynamic analysis of spatial mechanisms.


2013 ◽  
Vol 59 (No. 8) ◽  
pp. 372-377 ◽  
Author(s):  
W. Szulc ◽  
B. Rutkowska

The determination of a range of boron concentration in the soil solution, evaluation of the effect of physico-chemical soil properties on boron concentration in the soil solution as well verification whether boron quantity in the soil solution is sufficient for nutritional needs of selected plants cultivated in Poland were comprised. Average boron concentration in the soil solution of Poland&rsquo;s cultivated soils ranges from 0.59 to 5.07 &micro;mol/L and is differentiated by physico-chemical properties of soil. Taking into account decreasing effects of soil properties on the increase of boron concentration in the soil solution, the soil properties can be arranged as follows: organic C &gt;<br />soil abundance in available boron &gt; soil texture &gt; soil pH. The minimum boron quantity observed in the soil solution of Poland&rsquo;s cultivated soils was not sufficient to fulfil nutritional needs of the plants. The maximum boron quantity observed secured nutritional needs of cereals and potatoes but not those of rape plants and sugar beets. Based on the study it can be concluded that the measurement of the concentration of boron in the soil solution can be used in the diagnosis of deficiency of this element for crops.


2020 ◽  
Vol 896 ◽  
pp. 119-126
Author(s):  
Anca Didu ◽  
Nicolae Dumitru ◽  
Cristina Ileana Pascu ◽  
Violeta Cristina Contoloru

The analysis of the dynamic behavior of parts from the structure of the cationing mechanism of an internal combustion engine in 4 steps is followed. Thus, kinetic and dynamic models were developed for the motor mechanism considered as an assembly consisting of crankshaft, connecting rods, bearings and pistons. Dynamic models were built mainly in the Ansys program, based on the finite element method. The following problems were addressed, namely the dynamic analysis, with the determination of the response in time for displacements, stresses and deformations and also the vibration analysis in order to analyze the frequency response for the kinematic parameters of the whole system, but also of the component elements. Dynamic models for the numerical processing of the two types of analyzes were designed in a parameterized system with multiple possibilities of working on different time, frequency or different types of loadings and connection conditions. The purpose of this paper is to study the dynamic response of the main elements of the mechanism, for different types of materials. Given the wide field of applicability in automobiles, the technology for obtaining parts from sintered powders, the studies were realized for the cases when the connecting rod and the bearings are made of metallic powders, respectively of steel, to be extended for more complex cases, when we consider the influence of lubricant and temperature distribution in areas of practical interest.


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