SU1244531A1 - Method of testing shell structures by dynamic pressure - Google Patents

Abstract

The invention relates to the field of mechanical testing and can be used to study the strength and stability of a wide class of shell structures when loaded with dynamic pressure. The chain of the invention is to increase the reliability of the test results by eliminating the overloading of the structure during the pre-static loading process. The method of testing shell structures consists in preliminary static loading of the structure by creating different pressures from opposite sides of the structure ensuring the specified pressure drop and subsequent depressurization from the side opposite to the static load by an amount equal to the test dynamic pressure. To avoid overloading the structure during pre-static loading, the latter is carried out in two stages: first, both sides of the structure simultaneously create the same pressure equal to the test dynamic pressure, and then the pressure from the load is increased to a value that provides the specified differential pressure. 1 il. (L with to 4 4 SL CO

Description

The invention relates to mechanical tests, namely to a method for testing shell structures with a dynamic pressure, and can be used to study the strength and stability of a wide class of shell structures.

The purpose of the invention is to verify the accuracy of the test results by eliminating overloading of the structure during the process of preliminary static loading.

The drawing shows the scheme of the proposed method.

The method of testing shell structures by dynamic pressure consists in pre-static loading of the structure by creating different pressures from opposite sides of the structure and ensuring a predetermined pressure drop and subsequent pressure relief from the side opposite to the action. . static load, equal to the test dynamic pressure. The preliminary static loading is carried out in two stages: first, on both sides of the structure, they simultaneously create the same pressures equal to the test dynamic pressure, and then the pressure from the load side is increased to the value at which the specified differential pressure is maintained.

The method is carried out as follows.

The test shell construction 1 is placed in test chamber 2, the internal cavity 3 of construction 1 is connected via pipeline 4 with shut-off valves 5 and 6 with a pressure source (not shown) and cavity 7 of chamber 2, and through valve 9 with the atmosphere (or the collector of the working fluid) Cavity 7 of the chamber 2 through the shut-off valve 6 communicates with the pressure source, and through the valve 9 - with the atmosphere (or the collector of the working fluid). Before testing, valves 8 and 9 are closed. The working fluid (liquid or gas) from the pressure source through the open valves 5 and

6 simultaneously served in the cavity 3 and

7 until the pressure in each of them is measured by gauges 10

and P respectively, will not reach ve

In a

the values of Р „+ Рд, where Bj, is the test dynamic pressure; P - atmospheric pressure. After valve 5 is closed and pressure in cavity 7 is increased to the value at which

- a predetermined pressure drop is provided, which is required to create a pre-static load. Then the valve 6 is closed and the opening of the valve 8 relieves pressure from the cavity 3. In this case, the cladding structure 1 is loaded with external dynamic pressure.

The rate of increase in pressure from the PCT to Pet + Pd can be

different depending on the type and flow characteristic of the valve 8. After loading, the structure is unloaded by depressurizing the cavity 7 through the valve 9. The discharge rate is set in the same way as the load increase described. . ...

The described techniques for the implementation of pre-static loading exclude structural overload. When using others. methods of preloading (for example, when creating pressure P + 4-P at first only in cavity 3, and then creating pressure Pa + PC + PCI in cavity 7 or vice versa) before loading it with dynamic pressure is statically overloaded, which can lead to

not calculated its deformation or.

destruction. In the case of both cavities x 3 and Roth R. p.

if you first create pressure RS P and then relieve pressure from one of them to the pressure of RF + P, it is almost impossible to ensure that a given initial pressure drop is obtained, since as the pressure decreases in one cavity, the shell structure de45 is formed and the pressure in the other cavity also drops .

Claims (1)

Invention Formula The method of testing shell structures by dynamic pressure, according to which the tested structure is subjected to preliminary static loading by creating different pressures from opposite sides of the structure to provide a predetermined pressure drop, and then relieve pressure from the side opposite to static load by an amount equal to the test dynamic pressure that is different in order to increase the reliability of the test results by eliminating congestion ching in the preliminary nagouzheni static, pre stati2445314 The load is carried out in two stages, first on both sides of the structure they simultaneously create the same pressure, equal to the test dynamic pressure, and then the pressure from the load side is increased to the value at which the specified pressure drop is maintained. one L Compiled by V. Shekhter editor M. Petrova Tehred I. Popovich Proofreader M, Pojo Order 3907/45 Circulation 778 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035; Moscow, Zh-35, Raushsk nab. 4/5 Production and printing enterprise, Uzhgorod, st. Project, 4