RU114775U1 - DEVICE FOR RESEARCH OF STRESSED-DEFORMED STATE OF SMOOTH CONIC SHELLS - Google Patents

Abstract

A device for studying the stress-strain state of smooth conical shells, containing an elastic element, strain gauges, measuring equipment, characterized in that the elastic element is made in the form of a smooth conical shell, to which strain gauges are uniformly glued along the generatrix, with odd parallel and even perpendicular to the axis of symmetry , in the lateral part of the body of the device, a fitting is rigidly fixed, a loading system by axial forces is introduced into the device, consisting of a cover and a rod, and the rod is rigidly fixed with a pin to the body, in the lower part it is equipped with a pivoting lever, the cover of the conical shell is fixed through the strain gauge with connections to the stem, a strain gauge is glued to the strain gauge in the axial direction.

Description

The utility model relates to measuring equipment, in particular, to means for measuring the deformation of shell structures during strength tests and can be applied in aircraft manufacturing, mechanical engineering, shipbuilding, rocket science, etc.

A device for measuring deformation is known, comprising a support element for attaching to a controlled object, and electrodes of a capacitive gap sensor mounted on it, the support element is made in the form of L-shaped conductive plates, the protrusions of which are parallel to one another, have a dielectric coating facing each other surfaces and perform the functions of electrodes of a capacitive sensor. (RU No. 2040777, IPC G01B 7/16, published on July 27, 1995).

Closest to the proposed model is a device for measuring deformation during strength tests, containing an elastic element, a fastener for the elastic element, strain gauges located on the elastic element and measuring equipment, the elastic element is made of two thin-walled rings connected to each other in series along their axis symmetry by the node assigning the normalized value of the measured parameter, and in the attachment points and nodes of the task of the normalized value of the measured parameter the basic openings are made tions. (RU No. 2091702, IPC G01B 7/16, publ. 09/27/1997).

The disadvantages are the inability to study the stress-strain state of smooth conical shells, as well as the need for graduation of the device.

The purpose of the utility model is to increase the accuracy of measurements and expand the range of shell loads by various combined loads.

This goal is achieved by the fact that in a device containing an elastic element, strain gages, measuring equipment, the elastic element is made in the form of a smooth conical shell, to which the strain gages are uniformly glued, moreover, odd in parallel and even even perpendicular to the axis of symmetry in the side of the housing devices, the fitting is rigidly fixed, an axial loading system is introduced into the device, consisting of a cap and a rod, the rod being rigidly fixed with a pin to the body, in the lower part It is turned by a rotary lever, the conical shell cover is fixed through the strain gauge with a threaded connection to the rod, the strain gauge is glued in the axial direction to the strain gauge.

Significant differences and novelty are that the elastic element is made in the form of a smooth conical shell, to which strain gages are evenly glued, odd in parallel, and even, perpendicular to the axis of symmetry, a fitting is rigidly fixed to the side of the device’s body, a system is introduced into the device axial loading, consisting of a cap and a rod, the rod being rigidly fixed with a pin to the body, equipped with a pivot arm in the lower part, and the conical shell lid fixed through a tensor akan via a threaded connection to the stem, on tenzostakan axially gage pasted.

Analysis of the known technical solutions in the studied area and related areas allows us to conclude that there are no signs in them that are similar to the essential distinguishing features in the claimed device.

Figure 1 shows a utility model (General view).

The smooth conical shell 1 is fixed with the housing 2 on the base 3 through the seal assemblies 4. The nut 5 with the lever 6 is fixed in the lower part of the rod 7 by means of a threaded connection, to which, in turn, a pin 8 is rigidly attached from the bottom up to fix the rod 7. Strain gauge a glass 9 with a strain gauge 10 fixed thereon and a cover of a smooth conical shell 11 fixed on the rod 7. To the strain gauges 12 arranged so that the direction of the base coincides with the direction of the measured strain, reklyuchatel sensors and digital strain gauge bridge.

The device operates as follows. Turn on the digital strain gage bridge. From the digital display record the initial reading n _H. The shell 1 is loaded with axial compressive or tensile force. By turning the lever 6, it is ensured that a number appears on the digital display that differs from the initial report by the amount of deformation corresponding to a given force N.

The value of the compression force N (tension) is set by setting a predetermined strain value measured by the strain gauge 10 on the strain gauge cup 9 by the expression:

,

where r _CT is the tensor glass radius;

h _CT is the wall thickness of the strain gauge glass;

E _CT - modulus of elasticity of the material of the strain gauge glass.

Since the strain effect is characterized by the coefficient of strain sensitivity of the material:

,

where L, R is the initial length and resistance of the strain-sensitive material;

ΔL, ΔR - change in its length and resistance during deformation.

where

(n _P -n _H ) is the difference in the readings of the CTM-3 tensomost bridge after loading n _P and before loading n _H. The conical shell 1 is loaded with internal overpressure using a pneumatic system or external with a vacuum system. On the first two lamps of the digital display, the channel number is displayed, and the next three digits indicate shell deformation 1. Automatic sequential switching to the next channel by the number and displaying the corresponding indication n _Hi,.

To calculate the relative deformations, the following dependence is used:

,

and longitudinal and circumferential stresses, we use Hooke's law:

,

,

where ε ₁ is the relative longitudinal deformation,

ε ₂ - relative circumferential deformation.

This device allows you to measure circumferential and axial strains along the length of the generatrix of the conical shell, as well as evaluate the stress-strain state of the test specimen under combined loading and the margin of safety of the structure in various sections.

Claims (1)

A device for studying the stress-strain state of smooth conical shells containing an elastic element, strain gauges, measuring equipment, characterized in that the elastic element is made in the form of a smooth conical shell, to which the strain gauges are uniformly glued, odd in parallel, and even perpendicular to the axis of symmetry , a fitting is rigidly fixed in the side of the device’s body, an axial loading system is introduced into the device, consisting of a cover and a rod, and the rod is to fixed by a pin to the housing, the bottom part is provided with a pivoting lever, conical shell cover through tenzostakan secured by threaded connection to the stem, on tenzostakan axially gage pasted.