Assessment of the quality of the operation of agricultural nozzles on the basis of transverse volume distribution and spatial methods of analysis for stream spraying spectra is insufficient, and positive result do not guarantee that the intended and effective spraying effects are obtained. Tests were carried out to assess the quality of nozzles on the basis of transverse volume distribution analysis, microstructure characteristics, and detailed analysis of places where an unexpected change in the nature of the transverse volume distribution (increase in volume) was noted. The subjects of the study were RS11003 flat fan nozzles and a measuring stand equipped with a grooved table, which was used to carry out tests. During the tests, the unit flow rate from the nozzles, the transverse volume distribution of liquids from individual table grooves, and the corresponding CV distribution coefficients of variation were recorded. Detailed tests were carried out for the selected nozzle, consisting of spot measurement of droplet characteristics in individual liquid stream bands. The widths of these bands were constant and equal to the width of the measuring table groove. Measurements were made using analyzer 2D-Laser Doppler Anemometry/Phase Doppler Anemometry (2D-LDA/PDA) from Dantec Dynamics. The analysis of the results obtained from the grooved table and the droplet characteristics in individual stream bands showed clear and unexpected changes in the nature of the transverse volume distribution for all tested nozzles. These changes, consisting of a local increases in droplet diameters (with a reduced number of occurrences), can cause a significant reduction in the quality and effectiveness of spraying, despite the positive fulfillment of generalized normative criteria for their assessment.

The main objective of this work is to investigate the bridging tractions in a model composite using optical fiber Bragg grating (FBG) sensors written into selected reinforcing fibers. Simultaneously, the crack opening displacement (COD) is measured using a speckle interferometry technique. The measurements are useful in the verification of the relation between the COD and bridging tractions established with the use of the weight function method. Center crack specimens made of epoxy and reinforced with one layer of optical fibers are prepared and tested under remote tension parallel to the fibers. Bragg gratings of 0.17 to 0.38 mm in length are introduced in selected fibers for direct, non invasive, local measurements of axial strains in these fibers. A controlled central crack, bridged by intact fibers, is introduced by a laser technique such that the FBGs are located between the crack faces. The results on the forces obtained from the FBGs and the COD-weight function method show good agreement. The experimental results also compare very well with 3-dimensional numerical simulations of the actual specimen geometry and loading configuration.

The article presents the development of a structure model and numerical analysis of the trailer frame assembly intended for transporting bales of compressed straw, which may be a potential source of cheap and ecological energy. The aim of the analysis was to minimize the use of construction materials (reduction of the total weight), simplification of manufacturing technology, and thus energy savings in the production and operation. The aforementioned aspects also play a key role in environmental protection issues. The digital models of frame assemblies were made and subjected to static strength analysis. The structure was evaluated in terms of strength, based on the calculations made using the finite element method. The distribution of simulation parameters in the area of the tested structure made it possible to partially optimize the loadbearing system of the trailer, due to the adopted decision criterion in the form of reduction of the total weight and simplification of the structure, while meeting the limitations resulting from the values of stresses, displacements, safety factor in the admissible range. The material savings obtained for the optimal variant will result in simplification of manufacturing technology, energy savings and reduction of costs during production and operation.