ИССЛЕДОВАНИЕ НАПРЯЖЕННО-ДЕФОРМИРОВАННОГО СОСТОЯНИЯ СЖАТОГО ПЬЕЗОЭЛЕКТРИЧЕСКОГО СТЕРЖНЯ
МЕХАНИКА
Abstract
Modern micromechanics effectively integrates mechanical, electronic, computer systems into single devices which makes it possible to reduce the sizes of the devices created. This contributes to the development of such important directions of technology as mechatronics, biomechanics, in which much attention is paid to the development of microrobots, mechanisms of microtranslations, micromanipulators. In the mentioned mechanisms, piezomaterials are widely used as actuating elements, made in the form of rods, disks, rectangular plates, working on compression-stretching, bending, and shearing. The operetion of piezoelements, piezo drives, piezo actuators is based on the use of direct or reverse piezoelectric effects: the direct is the appearance of an electric charge in the deformation of a piezoelectric element, the reverselinear change in the size of a piezoelement when the effective electric field changes. The advantages of piezoelements over known mechanical systems are obvious. These are: small size, ability to provide micro-displacements, high positioning accuracy, speed, operation in statistical and dynamic modes, simplicity of design, stable operation at elevated temperatures and finally high strength. The use of piezoelectric elements in various devices requires the study of their stress-strain state depending on the action of the electric field. In the presented work, the project of the device for diagnostics of a flat-footed patient is offered. A piezocoupe is a rubber dielectric mat in which piezoelectric rods of circular cross section, working in the
mode of pressure sensors, are inserted with a large surface frequency. Due to precise modeling of the foot shape, the knowledge of the law of load distribution over the foot surface makes it possible to individually select the shape of the instep. The accuracy of the instep suppressor further reduces the further development of the flat feet, improves the blood supply to the foot and the lower leg, and softens the inevitable fluctuations at walking. The problem of the dependence of the electric field strength on the external load, acting along the axis of the piezoelectric rod is discussed. Three cases of the action of an external load in three directions of the coordinate axes of the rod are investigated. These problems are solved on the basis of the basic piezo-environment equations for the case of polarization of the material along the axis of the rod. The results are compared and analyzed. The practical application of research results is offered.
