Identification of Track Stability Model Parameters Based on Numerical Experiments

In the article, an identification method of railway track stability model parameters based on energy equilibrium is presented by the authors. A study of two parameters directly influencing the continuous welded track (CWR) stability is described by the authors, i.e., the rail-sleeper structure stiffness Bz is considered one beam, and the ballast lateral resistance r0. These parameters were estimated with the use of a numerical model for various railway track types. The adopted concept is based on the assumption that it is possible to determine substitute values for both parameters. Therefore, using one value of both of these parameters, we label them substitute parameters. The assumed numerical model forced lateral displacements of a track section, and, based on the obtained track section displacement results, energy equilibrium was determined. The equilibrium takes into account the work of external load and the bending work of rail-sleeper structure with the substitute stiffness Bz and the ballast deformation work, also with the substitute value of lateral resistance r0 with lateral displacement. The aim is to identify these substitute values to be used for analysing track stability with the semi-analytical model. These analyses are part of the studies related to the development of a method of assessing various methods of increasing track stability.

Studying standard and rheological quality parameters of winter wheat by Python visualisation

This study was carried out to present an innovative solution for interpreting large data sets in agri-statistics with the invocation of programmed visualisation. Moreover, the following polyfactorial long-term experiment embodies a comprehensive study of 18 wheat quality parameters. The effect of increasing dosages of fertiliser (control, N₉₀PK, N₁₅₀PK) was examined on 3 winter wheat cultivars (KG Kunhalom, GK Csillag, Hybiza) in two consecutive growing seasons (2018–2019). The ecological conditions of 2018 gave a significantly higher yield, meanwhile 2019 significantly augmented gluten spread, alveographic tenacity, alveographic deformation work, valorigraphic stability and quality group and loaf volume. N₉₀PK dosage was enough to realise yield and quality potential as well. Fertilising significantly improved 13 indices, namely yield, crude protein, Zeleny index, wet gluten content, alveographic extensibility, alveographic deformation work, valorigraphic water absorption, quality number and group, dough development time, stability, softening and loaf volume. Considering yield, cv. Hybiza performed better, while cvs. KG Kunhalom and GK Csillag possessed significantly better protein-linked postharvest attributes. One of the most important findings is that waffle chart, joint plot, correlation matrix and complexradar of Python provide a very powerful tool in agri-statistics. Also, the results can potentially improve the knowledge about cultivar-specific agronomy practice, wheat quality and the connections between these parameters.

Results verification of numerical simulation of the side impact of a vehicle in a three-point bending test

The research objective was to use numerical simulation to verify safety characteristics of deformation zone reinforcements subjected to bending, obtained from experimental results of the stretch-bending test. The methodology proposed for result verification by means of numerical simulation using a three-point bending test was verified on a sheet metal strip made of micro alloyed steel H 220 PD and a two-phase ferritic-martensitic steel DP 600. Material data for the material model according to Krupkovsky were determined in the tensile test. The measured data were processed tabularly and graphically. A comparison of the deformation work constant and the stiffness and deformation force constants shows that a very good match between the measured and the calculated characteristics has been achieved. Based on the data obtained, it can be assumed that it is possible to reduce the weight of deformation elements while maintaining the required safety characteristics by replacing micro alloyed steel H 220PD with the two-phase DP steel.

Investigation of Deformation Work in Layers of Explosion-Welded Composite Al-Cr-St3

The article is aimed at studying the distribution of deformation work in the layers of the explosion-welded composite Al-Cr-St3 with a diffusion barrier. It is established that the thickness of the chromium layer does not affect the value of the total deformation work. An increase in the thickness of the chromium interlayer leads to a decrease in the proportion of deformation work and strength.

Deformation of elastic-viscous beams by explosive load in water

Представлено аналитическое решение задачи о деформировании взрывом сосредоточенного заряда конденсированного взрывчатого вещества (ВВ) балки, материал которой чувствителен к скорости деформации. Влияние внешней среды (воды) на процесс и результаты деформирования учитывается введением присоединенной массы. Коэффициент вязкости и модуль упругости в фиксированных интервалах скоростей деформирования определяются из экспериментов. Для этих параметров, характеризующих материал балки при импульсном деформировании, получена аналитическая взаимосвязь и нижняя граница значений для коэффициента вязкости. Решение задачи найдено методом разделения переменных в определяющем уравнении движения. При этом форма упругой линии балки для каждого момента времени выбрана, исходя из требования выполнения граничных условий и принципа минимума работы деформирования. An analytical solution to the problem of deformation by an explosion of a concentrated charge of a condensed explosive (HE) of a beam, the material of which is sensitive to the rate of deformation, is presented. The influence of the external environment (water) on the process and the results of deformation is taken into account by introducing the added mass.The viscosity coefficient and the modulus of elasticity in fixed intervals of strain rates are determined from experiments. For these parameters, which characterize the material of the beam under impulse deformation, an analytical relationship and a lower limit of values for the viscosity coefficient are obtained. The solution to the problem is found by the method of separation of variables in the governing equation of motion. In this case, the shape of the elastic line of the beam for each moment of time is selected based on the requirement to fulfill the boundary conditions and the principle of minimum deformation work.

Theoretical Analysis of Bulletproof Capability of Multilayer Ceramic Composites Subjected to Impact by an Armor Piercing Projectile

Inspired by the theories of Tate and Zaera, a theoretical analysis model including the erosion of the projectile, the cracking of ceramic composites, and the deformation of metal backplate was established in this study to investigate the bulletproof capability of the ceramic composites under impact by an armor piecing projectile (AP). The analysis results were verified by ballistic tests. As for the ceramic composites, the volume of the cracked ceramic conoid and the change in the compressive strength were included. Regarding the deformation of the metal backplate, the plastic deformation work, the external work, and the conservation of kinetics were considered. Based on the thickness of the target plate, failure modes were separated into the plug type and the petal type. The ordinary differential equation solver of MATLAB, ode45, was adopted to solve relevant ordinary differential equations. In this study, the powder metallurgy was used to produce the Al2O3/ZrO2 multilayered ceramic composites of three layers; each layer was 3 mm in thickness. The ceramic composites were paired with a backplate made of 6061-T6 aluminum alloy with a thickness of either 1 mm or 4 mm. The ballistic tests were executed by using 0.30″ AP projectiles to impact the specimens. The results from theoretical model and ballistic tests were compared and shown consistent in the field of residual velocity, residual bullet mass, and the failure modes of the metal backplate.

Physicochemical and rheological properties of the derivatives of Ningmai 9 wheat and their relationship with sugar-snap cookie diameter

In recent years, the annual demand for soft wheat in China has exceeded six million metric tons. The development of soft wheat is an important objective in the Yangtze River Basin winter wheat region in China. Ningmai 9 is a soft wheat cultivar widely used as a parent in the soft red winter wheat breeding program. However, the physicochemical and rheological properties of Ningmai 9 and its derivatives remain unknown. In this study, Ningmai 9 and its thirty-one derivatives were grown in Nanjing in Jiangsu Province in two successive cropping seasons from 2015 to 2017. The kernel samples were analyzed for milling quality, solvent retention capacity (SRC), alveograph parameters, and sugar-snap cookie diameter. The flour protein content was not significantly associated with any other quality trait. P, L, P/L (the ratio of tenacity to extensibility), alveograph deformation work (W), and four types of SRC were significantly correlated with sugar-snap cookie diameter. Compared to Ningmai 9, seven wheat genotypes had relatively better cookie quality and lower SRC and P values. A multiple regression model with water SRC (WSRC) as a variable explained 72.5% of the total variation in cookie diameter. These results suggest that decreasing SRC and gluten strength is the key to improving soft wheat breeding programs.

Briquetting of structurally inhomogeneous porous materials

The work is devoted to solving the axisymmetric problem of the theory of pressing porous bodies with practical application in the form of force calculation of metallurgical processes of briquetting small fractional bulk materials: powder, chip, granulated and other metalworking wastes. For such materials, the shape of the particles (structural elements) is not geometrically correct or generally definable. This was the basis for the decision to be based on the continual model of a porous body. As a result of bringing this model to a two-dimensional spatial model, a closed analytical solution was obtained by the method of jointly solving differential equilibrium equations and the Guber–Mises energy condition of plasticity. The following assumptions were adopted as working hypotheses: the normal radial stress is equal to the tangential one, the lateral pressure coefficient is equal to the relative density of the compact. Due to the fact that the problem is solved in a general form and in a general formulation, the solution itself should be considered as methodological for any axisymmetric loading scheme. The transcendental equations of the deformation compaction of a porous body are obtained both for an ideal pressing process and taking into account contact friction forces. As a result of the development of a method for solving these equations, the formulas for calculating the local characteristics of the stressed state of the pressing, as well as the integral parameters of the pressing process are derived: pressure, stress, and deformation work.

The Selection of Materials for the Auto-Body Deformation Zones

Nowadays, it is important to select the proper material for parts of the car-body’s deformation zones in terms of passenger safety. Due to wide range of high-strength steels on the market, the article presents the way of selecting the material by determining the deformation work and the stiffness constant, both measured by the stretch-bending test. The procedure was verified on a high-strength micro-alloyed steel HSLA, high-strength multi-phase steels DP 600 and TRIP, and an austenitic stainless steel AISI 304. The results indicate the austenitic steel is better to use in the deformation zones for the frontal impact, while multi-phase steels are more suitable for deformation zones at the lateral impact. The regression model describing the dependence of the deformation work measured at the stretch-bending test and the deformation work measured at uniaxial tensile test was defined as well. The model allows predicting the deformation work at stretch-bending test based on the mechanical properties measured by the tensile test.

The Technological Properties of Polymer Composites Containing Waste Sheep Wool Filler

New technologies are using natural fibres in composites materials in the industry. It is still often natural fibres in modern buildings, chemists, airports, sport and automotive. Using for construction pieces and their better properties than steel or traditional materials. New forward science and technic are recycled or decrease waste. The problem for central Europe is a waste of agricultural, invention relates to an epoxy resin filled with an organo-inorganic filler of natural origin, production especially plants and sheep wool as well as other usable wastes such as old textiles. New applications are in new construction types and industries finding cheaper materials. There is available modern technology for injection moulding granulate polypropylene with filler from sheep wool and plant fibres. For example, to make furniture or building cladding. This could reduce waste production, pollution of nature and emissions in the production of these products from new raw materials. The work presents the possibilities of using new polymer-based materials contain sheep wool as filler. The paper deals with the evaluation of the mechanical properties of the effect of the addition of sheep wool in a concentration of 3% to selected types of thermosetting matrices. In the experiments, the modulus of elasticity, tensile strength, ductility and deformation work were built on the sample set. The results are statistically processed and document the possibilities of adjusting the mechanical properties of composites with sheep wool.