Simulation of mechanical parameters of sprayer boom

Abstract

The sprayer boom is a large and complex structure, used to support the spray nozzles. It is important to control and minimize the vibration of the structure on the vertical and horizontal planes, in order to insure the uniformity of pulverization over the field. Owing to the large spray boom widths, flexible behaviour of spray booms becomes important. Even small deformations of the structure can cause, by the large spray boom width, considerable displacements at the boom tips. However, there is not a clear correlation between the boom width and the amount of the spray boom motion. Another important factor is whether it concerns a trailed or a mounted sprayer. As spray boom motions play a dominant role on the spray distribution pattern, spray boom stability is important. Theoretical studies, simulations and field experiments have indicated that due to the spray boom vibrations, spray deposit distribution varies between 0 and 80 %. In this paper the static and dynamic study of a sprayer boom structure of about 24 m length is presented. Starting from the CAD model of the sprayer boom structure, a standard mesh procedure as a preprocessing step of a finite element analysis has been followed. Mainly shells, a reduced number of solid elements and rigid connection elements were used. The purpose of the static linear analysis was to determine the state of tension and deformation that develop in the boom during its exploitation. The geometric model made for the linear static analysis using the finite element method comprises several steps and highlights the mechanical response of the structure. An important parameter of the dynamic behaviour is the boom vibration amplitude. This parameter was observed in the finite element analysis of the boom structure considered at a natural scale. Other similar parameters, such as the resonant frequencies, have been observed.

Parameters for Modeling Passive Suspensions of Spray Bars

“…A more rigid structure would yield closer results between the models. Corroborating the observations of Engel ( 2008) and Manea et al (2018), the authors found that the horizontal deformations of the bars contributed to increased oscillation amplitudes. However, the rigid-body motions of the suspension cannot be neglected in this orientation.…”

“…According to Herbst et al (2018), there is no standard method to test the accuracy of sprayer boom suspensions objectively. Different modeling techniques have been used to represent suspension systems and sprayer booms, such as those based on undeformable bodies (Pontelli et al, 2010 and2009;Tahmasebi et al, 2018) and those based on deformable elements (Koc, 2015;Manea et al, 2018). Alternative modeling was presented by Bjornsson et al (2013), with rigid segments connected by torsional springs to represent the horizontal stiffness of the bar.…”

Mechanical Parameter Inversion in Sandstone Diversion Tunnel and Stability Analysis during Operation Period

“…The 70-day monitoring values of the four monitoring points of K3+950 monitoring section were imported into the initial training sample as an input vector and four mechanical parameters were output. The results were as follows: η1 =7.11×10 17 Pa·s, E1 =39 Pa, η2 =1.27×10 16 Pa·s and G2 =1.80×10 11 Pa. Other mechanical parameters required for the establishment of the rheological model are shown in Table 3. The inversion parameters were imported into the calculation model, and the rheological displacement of each monitoring point in the section for 70 days was obtained through numerical simulation.…”

“…A large number of experimental studies show that the mechanical parameters of the deep buried surrounding rock show significant attenuation characteristics with the increase of strain from the rheological attenuation stage to the acceleration stage [7][8][9][10][11]. However, the existing models for predicting the long-term stability of surrounding rocks all take mechanical parameters as constants for calculations and their models can only be applied to environments where the depth of surrounding rocks is relatively shallow.…”

Advanced Control Subsystem for Mobile Robotic Systems in Precision Agriculture

“…The agricultural activities subjected to this research were carried out in the field [1, 3, 7-10, 13, 14], in the greenhouses [2], or in the nurseries and were: herbicide spraying [1,3,8,14,22] and harvesting of heavy products (such as pumpkins) [9].…”