The application of the boundary element method to the calculation of a closed circular cylindrical shell of step-constant thickness, loaded over the entire surface by a uniform normal pressure, is described. The numerical example is considered. The results of the calculation are compared by two numerical methods – boundary and finite elements.

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В. П. Квасников, д.т.н., А. О. Возняковский МЕТОДИКА БАЛАНСИРОВКИ ЧУВСТВИТЕЛЬНОГО ЭЛЕМЕНТА МАЯТНИКОВОГО АКСЕЛЕРОМЕТРА Маятниковые акселерометры широко применяются в космических аппаратах, авиации, автомобилестроении, ракетах и кораблях. Один из важнейших элементов конструкции маятниковых акселерометров-подвесы, их форма и размеры определяют важный параметр приборов-чувствительность. На чувствительность подвеса влияют маятниковость и совпадение центра масс с осью горизонта или вертикали. В статье идет речь о методике балансировки чувствительного элемента. Ключевые слова: маятниковый акселерометр, чувствительный элемент, балансировка. V. Kvasnikov, PhD, A. Vozniakovskyi THE TECHNIQUE OF BALANCING THE SENSITIVE ELEMENT OF THE PENDULUM ACCELEROMETER Pendulum accelerometers are widely used in spacecraft, aircraft, automotive, missiles and ships. One of the most important elements of the design pendulum accelerometers-suspension, their shape and dimensions determine an important parameter of the instrument-sensitivity. On sensitivity affects pendular and coincidence the center of mass with horizontal or vertical axis. The article deals with the method of balancing the sensor element.

The work uses modern numerical methods of mechanics of a deformable solid to analyze the stress-strain state of orthopedic structures in order to improve them and improve the quality of treatment of patients. Among the many numerical methods, the attention of the authors was drawn to the finite element method and to the numerical and analytical method of boundary elements in the author's edition. Settlement models of both metal apparatuses and parts of a person’s arm with a fracture are constructed. The stress – strain state in various zones of the biomechanical system was calculated. It is shown that the numerical-analytical method of boundary elements allows obtaining more accurate results with fewer equations in the resolution system. It is noted that in the case of the considered biomechanical systems, its elements undergo tension – compression, shear, torsion, and bending. To consider them, solutions are presented for Cauchy problems, which are included in the general system of resolving equations of the MGE. It is shown that, unlike the FEM, the MGE simplifies the algorithm for calculating biomechanical systems. Comparison with the FEM results shows their good agreement, which proves the reliability of the calculation results of both methods.

The article deals with modeling and calculations of volumetric machine-building structures with complex geometry. The relevance of the work lies in the fact that its methodology and results can help design massive structural elements complex in shape, including cylinders of powerful hydraulic presses. Attention is paid to the problems of reducing the metal content of machine-building products and the safe conditions of their operation. Theoretical and applied work is based on numerical methods using analytical solutions to assess the reliability of computer calculation results. The choice of research method is because analytical solutions for massive parts of such a configuration are too complex for numerical implementation. Experimental methods are too expensive and not so universal as to sort out possible variants of shapes and sizes. For the actual model of the press, the capabilities of the finite element method implemented in the ANSYS multipurpose complex were selected and rationally used. The results of the calculations are summarized in the table and shown on the graphs of the stress distribution. Based on the performed calculations (with a reliability check based on the formulas of the theory of elasticity for simplified calculation schemes), conclusions were made to ensure a more even distribution of stresses and a reduction in the metal content of the product.