# stiffness

## Classical approach to determining the natural frequency of continual subsystem of three-mass inter-resonant vibratory machine

Problem statement. The three-mass vibratory system can be defined by five basic parameters: inertial parameters of the masses and stiffness parameters of two spring sets. Unlike the classical discrete system, the discrete-and-continual one consists of two rigid bodies connected by one spring set that form the discrete subsystem, and of the reactive mass considered as deformable (elastic) body characterized by certain stiffness and inertial parameters, which are related with one another.

## RESEARCH OF STRENGTH AND DEFORMATIVITY OF PRESTRESSED MULTI-SPAN BEAM OF LENGTH 18 m UNDER DIFFERENT LOADING MODES

The paper presents only some problems of design and constraction of the bridge. The aim of the experimental study is to establish the behavior peculiarities of multi-span structure under the external static loading. The development of structure calculation methods for multispan reinforced concrete while taking into count the stages of its work is necessary to increase the effectiveness and widespread use of it. Improvement of structure calculation methods is an important problem.

## Substantiation of Parameters and Analysis of Operational Characteristics of Oscillating Systems of Vibratory Finishing Machines

The calculation diagrams of oscillating systems and operation features of vibratory finishing machines are considered. The mathematical models of three-mass and four-mass oscillating systems are presented. The amplitude values of the oscillating masses displacements are derived. The functions of inertial and stiffness parameters optimization are formed. The optimization problems are solved with a help of MathCAD software.

## Ways of Improvement of Operational Efficiency of Hopper Devices

The operation of hopper devices, which are used in industry, civil engineering, agriculture and transport, is analyzed on the article. The external factors, which influence the process of charging, storing and discharging of loose cargo (freights) from hopper tanks, are overviewed. The subject of research of presented paper is the improvement of mechanisms of fracturing of products hangs-up (bridges) in hoppers at the stage of designing and setting up of hopper devices.

## Dynamics of pulse signal forming from distal zones of radial arteries

In last time new methods and hardware-software system, which combine eastern medicine traditions and western technologies are commonly used in diagnostic practice. Pulse diagnostics is one of the ancient methods for disease state identification. For diagnostic purposes different kind of arteries zones can be observed, but most popular is pulse diagnostics of wrist joints radial arteries. It is based on recording of signal from three zones, lied closely along the radial arteries of left and right hands. For the purpose of pulse diagnostics special kinds of sensing devices are used.

## Дослідження роботи збірно-монолітних плитно-ребристих конструкцій прогонових будов мостів з тріщинами і до руйнування

The active provides the results of experimental reseach abtain in investigation of the testing multi – span prestresset rein reinforced reinforced concrete bridges.

## Експериментальні дослідження бездіафрагмової прольотної будови моста під час реконструкції

Тechnique and results of static tests of reinforced concrete without-diaphragm span structure before and after reconstruction are described.

## Експериментальні дослідження міцності та деформативності армокам’яних згинаних елементів

The results are given on the basis of an experimental research on firmness and deformability of normal sections of concrete beams reinforced with frameless reinforcement and rod reinforcement class A400C without prestressing. These experiments and comparing them with calculations according to current regulations give an opportunity to assess the convergence of the results and draw conclusions about the possibility of rational design of ceramic block bending elements with double reinforcement in the area of the normal forces.