Study of lifting platforms using three-dimensional computer-aided modeling

In the modern world, an aerial platform (auto-hydraulic lift) is an integral part of a rich model range of special crane equipment. The first primitive lift consisted of a lever, hinged on the base. A traction rope was placed on one side of the lever, and a counterweight on the other. With the help of his own physical strength, a person was able to rise to a small height using such a simple lifting mechanism. Currently, many types of lifts are used, which differ in height characteristics and the design of the lifting mechanism. Goal. The aim of this work is to study the kinematics of the moving elements of a hydraulic lift using a virtual model created on the basis of the Autodesk Inventor Professional software package. The model is based on an existing physical object. To study the kinematics of individual units and the installation as a whole, we use the method of modeling individual units and units of a machine, collecting them into a single mechanism with the task of all possible movements of structural elements in the Inventor package. Methodology. The assigned tasks can be solved by special design tools that are included in the software product, namely the environment for dynamic modeling, stress analysis. These tools are accessed while working in the "Assembly" environment, using the ribbon tabs "Design" and "Environments". The results of further research will bepresented in future publications.

Modeling stress-strain state of the section of human dental apparatus with the account of contact interaction between the teeth and their partial absence

Complex interaction of incisors of the multi-element system “jaw – tooth – periodontium – enamel – dentinˮ is considered in the present work. The model was created on the basis of tomographic images taking into account previous studies of the human dental apparatus for a simplified model of three molars. The aim of the work is to determine the stress-strain states of the “jaw – periodontium – tooth – dentinˮ system for a different number of incisors and their location using three-dimensional computer finite-element modeling. The results of the study allow obtaining a more complete and accurate assessment of the state of the human dentofacial apparatus as a whole and each of its elements separately in order to improve the technologies and methods of prosthetics.

Geometric Modeling of Stress Visualization Tools Based on the Functional-Voxel Method

One of the approaches to the construction of graphic images of the stress state for the force vector applied to a point is considered in this work. Has been proposed a geometric model for a continuous medium, formed by a bunch of projection planes for each point of the examined object’s space. This permits to obtain a model for a volume vector in the form of a distributed decomposition into stress components at each point specified by a bunch of projection planes. The building a model for a volume vector, defined as a set of specified laws of direction and length, in the context of modeling stress from an applied force vector to a selected point, is based on strength of materials’ classical laws for calculation the stress state values at an inclined section. Such approach allows use a voxel graphic structure for computer representation of the simulated stress, rather than a finite element mesh. In such a case, there is no obtained result’s error dependence on the spatial position of the mesh nodal points, which is often a problem in FEM calculations. The resulting functional-voxel computer model of the volume stress vector is a structural unit for modeling the distributed load on areas of complex configuration. In this case, the elementary summation of such vectors allows any uneven distribution of the load relative to each point on the specified area. The considered approach works well with geometric models initially represented analytically in the form of a function space (for example, models obtained by the R-functional modelling – RFM-method), and reduced to functional-voxel computer models. A method for deformation modeling based on obtained stresses by means of local transformations of the function space, describing the investigated geometric object, is demonstrated.

Diagnostics of frost resistance of grape varieties in the conditions of stress modeling

Диагностика степени устойчивости сортов винограда к морозу играет важную роль в селекции, поскольку лишь имея полную точную информацию о присущей конкретному генотипу степени выраженности признака возможно использование его в качестве источника ценного признака в процессе гибридизации. Задачей наших исследований являлось определение степени морозоустойчивости сортов винограда при моделировании стресса в лабораторных условиях с целью отбора наиболее перспективных сортов для включения в селекционный процесс. В исследования включены 53 сорта винограда различного происхождения, в том числе сорта-индикаторы с ранее установленной градацией признака морозоустойчивости. Наибольшую степень устойчивости к стрессу (минус 27 С - 9 баллов по шкале МОВВ) показали сорта Кинг Руби, Молдова, Саперави северный и Берландиери х Рипариа Кобер 5ББ (контроль), обеспечив при этом 100 %-ную сохранность центральных почек. В группу сортов, показавших устойчивость к морозу до минус 24С (7 баллов), определены сорта Альминский, Альминский белый, Атлант, Красностоп золотовский, Мускат ранний, Сибирьковый, Фогельтраубен и контрольный сорт Цитронный Магарача, которые обеспечивают 100 %-ное прорастание центральных почек после промораживания при температуре минус 24С. В ходе анализа данных использованы пять параметров оценки устойчивости к стрессу: % проросших глазков, среднее значение длины проросших побегов, а также количество и длина образовавшихся корней, развитие соцветий. Использование кластерного анализа позволило определить сходство и различия сортов между собой по заданным параметрам. Исследуемые сорта разделились на два различных между собой кластера. Наибольший интерес для селекционной работы представляет кластер, включающий в себя 21 сорт винограда. Эти сорта среди изученных обладают максимальной устойчивостью к стрессу по комплексу параметров. Среди устойчивых к воздействию морозов сортов винограда максимально близкий к контрольному сорту Берландиери х Рипариа Кобер 5ББ является сорт Саперави северный (Ed =0,21). Diagnostics of the resistance degree of grape varieties plays an important role in breeding, since the use of frost resistance parameter as a valuable feature in the process of hybridization is possible only having complete and accurate information about the degree of its expression peculiar for a particular genotype. The objective of our research was to determine the degree of frost resistance of grape varieties when modeling stress in laboratory conditions in order to select the most promising varieties for breeding process. The study covered 53 grape varieties of different origin, including varieties-indicators with previously established gradation of frost resistance parameter. The highest degree of resistance to stress (minus 27°C - 9 points by the OIV scale) showed the varieties ‘King Ruby’, ‘Moldova’, ‘Saperavi Severnyi’ and ‘Berlandieri x Riparia Kobera 5BB’ (control), providing 100% preservation of the central buds. Another group of varieties (7 points): ‘Alminski’, ‘Alminski Belyi’, ‘Atlant’, ‘Krasnostop Zolotovskiy’, ‘Muscat Ranniy’, ‘Sibirkovyi’, ‘Vogeltrauben’ and the control variety ‘Tsitronnyi Magaracha’ provided 100% germination of central buds after freezing at minus 24 ° C . In the process of data analysis, five parameters of stress resistance assessment were used: % of sprouted eyes, average value of length of sprouted shoots, number and length of formed roots, the development of inflorescences. Using of the cluster analysis allowed us to determine the similarity and difference of varieties from each other by given parameters. The studied varieties were divided into two different clusters. The biggest interest for breeding work by the complex of parameters gained the cluster of 21 grape varieties with maximum resistance to stress. Among frost-resistant grape varieties the nearest to the control ‘Berlandieri x Riparia Kober 5BB’ was ‘Saperavi Severnyi’ variety (Ed = 0.21).