CN-122016186-A - Method for monitoring air pressure abnormality of inflatable film structure for distinguishing temperature change and gas leakage

CN122016186ACN 122016186 ACN122016186 ACN 122016186ACN-122016186-A

Abstract

The invention belongs to the technical field of health monitoring and state evaluation of inflatable film structures, and provides an air pressure anomaly monitoring method of an inflatable film structure for distinguishing environmental temperature change and air leakage. According to the method, firstly, under the conditions that the structure is well sealed and no gas leaks, a finite element analysis model of the inflatable film structure is established and corrected through measured data, theoretical values of air pressure inside the structure under different temperature working conditions are obtained, and then a temperature-air pressure mapping relation is established and a theoretical air pressure calculation module is formed. In the actual operation process of the structure, internal temperature and air pressure data are collected in real time, theoretical air pressure values under corresponding temperature conditions are obtained based on the theoretical air pressure calculation module, the theoretical air pressure values are compared with actual air pressure, air pressure deviation is calculated, and the air pressure deviation value and the persistence thereof are judged in a combined mode through setting an air pressure deviation threshold value and a time window, so that normal air pressure fluctuation caused by environmental temperature change and abnormal air pressure change caused by air leakage are effectively distinguished, and accurate identification and early warning of micro leakage of an inflatable film structure are realized. The invention can reduce the misjudgment risk caused by temperature interference and improve the reliability and safety of the pneumatic monitoring of the pneumatic film structure.

Inventors

LIU FUSHOU
Li Shuanchun
PAN WENGUANG

Assignees

南京林业大学

Dates

Publication Date: 20260512
Application Date: 20260114

Claims (9)

1. The method for monitoring the air pressure abnormality of the inflatable film structure for distinguishing the temperature change and the air leakage is characterized by comprising the following steps of: Step 1, under the condition of no gas leakage, establishing a finite element analysis model of an inflatable film structure based on an actual inflatable film structure; Step 2, when the inflatable film structure is confirmed to be in a state without gas leakage, acquiring actual internal air pressure and temperature data of the inflatable film structure under at least one temperature working condition, comparing the actual internal air pressure with corresponding theoretical air pressure obtained by the finite element analysis model, and carrying out parameter correction on the finite element analysis model according to a comparison result to obtain a corrected air pressure prediction model; Step 3, based on the corrected air pressure prediction model, analyzing the internal air pressure response of the inflatable film structure under different temperature working conditions to obtain reference data reflecting the relation between temperature change and air pressure change; Step 4, constructing a theoretical air pressure calculation module based on the reference data, wherein the theoretical air pressure calculation module is used for obtaining a corresponding theoretical air pressure value under the condition of a known structure temperature; Step 5, in the actual operation process of the inflatable film structure, monitoring data of the temperature and the air pressure inside the structure are collected in real time; Step 6, calculating a theoretical air pressure value under the condition of collecting temperature in real time, comparing the theoretical air pressure value with an actual air pressure value collected in real time, and calculating to obtain a corresponding air pressure deviation value; And 7, when the air pressure deviation value continuously exceeds a preset threshold value in a preset time window, judging that the air pressure abnormality caused by air leakage exists in the inflatable film structure, and outputting early warning information.
2. The method of claim 1, wherein step 1 comprises establishing a finite element analysis model based on the geometric parameters, the material mechanical parameters, the initial air pressure parameters, and the initial temperature parameters of the inflatable membrane structure in ANSYS APDL modeling software.
3. The method of claim 1, wherein the modifying the parameters comprises modifying at least one equivalent parameter of the finite element analysis model, the equivalent parameter including at least one or more of a structural equivalent volume parameter, an initial gas pressure parameter, and a gas thermal parameter, and re-performing a computational analysis on the finite element analysis model based on the modified equivalent parameter.
4. The method for monitoring air pressure anomaly according to claim 1, wherein step 3 comprises determining a variation range of the temperature working condition according to an actual use environment of the inflatable film structure, and analyzing the model from low to high according to different temperature working conditions respectively to obtain a temperature-air pressure corresponding relation data set.
5. The method for monitoring air pressure anomaly according to claim 1, wherein the step 4 comprises the steps that the theoretical air pressure calculation module is an independent software function module or an embedded calculation module and can be deployed in a structural health monitoring system or an upper computer monitoring system, and the theoretical air pressure calculation module is established based on the reference data and adopts a table look-up calculation, interpolation calculation or fitting calculation mode to output a corresponding theoretical air pressure predicted value after the current temperature value of a structure is input.
6. The method of claim 1, wherein step 5 includes synchronously collecting temperature data and barometric pressure data within the structure at a predetermined sampling frequency via a temperature sensor and a barometric pressure sensor disposed within the inflatable membrane structure.
7. The method of claim 1, wherein the air pressure deviation is a relative deviation between an actual monitored air pressure value and a theoretical air pressure predicted value at a corresponding temperature.
8. The method for monitoring air pressure abnormality according to claim 1, wherein step 7 comprises setting the time length of the preset time window according to the air pressure stability requirement of the inflatable membrane structure and the time resolution of the monitoring system, wherein the preset threshold is a threshold determined according to the air pressure fluctuation range allowed by the inflatable membrane structure, and judging the air pressure abnormality as transient abnormality caused by external transient disturbance when the air pressure deviation exceeds the preset threshold in a short time but does not continuously reach the preset time window, and not triggering leakage early warning.
9. The method of claim 1, wherein the parameter correction in step 2 and the temperature-air pressure analysis in step 3 are performed repeatedly periodically or as needed during operation of the inflatable membrane structure, and the reference data is updated to achieve continuous updating of the air pressure prediction model.

Description

Method for monitoring air pressure abnormality of inflatable film structure for distinguishing temperature change and gas leakage Technical Field The invention belongs to the technical field of health monitoring and state evaluation of an inflatable film structure, and relates to a method for judging whether air pressure change in the inflatable film structure is caused by air leakage or not under the condition of environmental temperature change. Background The inflatable film structure is a light structural form which maintains structural form and bearing capacity by means of internal gas pressure, has the advantages of light weight, foldability, easiness in deployment and the like, and is widely applied to the fields of temporary construction, engineering protection, spaceflight expandable structures and the like. After the inflation is completed, the stability of the air pressure in the structure has an important influence on the service safety of the structure. In the actual use process, the ambient temperature of the inflatable film structure often changes with time, and the structure and the temperature of the gas inside the structure change with time, so that the internal gas pressure changes. The air pressure fluctuation caused by temperature change belongs to normal physical phenomenon and does not represent abnormal structure. However, in the long-term service process, the inflatable film structure may generate gas leakage due to external micro damage or other reasons, especially early micro leakage, and the air pressure change amplitude caused by the gas leakage is small, and the gas pressure change is easy to be overlapped with air pressure fluctuation caused by temperature change, so that the gas leakage is difficult to distinguish. The existing air pressure monitoring method mostly adopts a mode of real-time measurement and fixed threshold judgment, and usually does not fully consider the comprehensive influence of environment and structural temperature change on internal air pressure, so that the problem of false alarm or missing alarm is easy to occur. The method is characterized in that the method comprises the steps of obtaining the air pressure change rule of the inflatable film structure under different temperature conditions through long-term operation monitoring or experimental testing, wherein the method usually needs a long time to cover the temperature working condition range possibly experienced by the structure in the actual service process, and complete and reliable data are difficult to obtain in the initial deployment or short-term operation stage of the structure. Therefore, under the condition that the environmental temperature change and the tiny gas leakage of the structure are possible at the same time, a method capable of establishing a reliable air pressure reference and distinguishing the air pressure change causes is needed to realize accurate identification and early warning of the abnormal gas leakage of the inflatable film structure. Disclosure of Invention Aiming at the problem that in the prior art, under the condition that the ambient temperature change and the tiny gas leakage of the structure exist simultaneously, the cause of the air pressure change inside the inflatable film structure is difficult to accurately distinguish, and misjudgment or missed judgment is easy to occur, the invention provides an air pressure anomaly monitoring method for the inflatable film structure, which is used for distinguishing the temperature change and the gas leakage. According to the invention, a finite element analysis model of the inflatable film structure is established and corrected, theoretical air pressure response rules corresponding to different temperature working conditions under the leakage-free condition are obtained, and in the actual operation process of the structure, the real-time monitoring air pressure and the theoretical air pressure are compared and analyzed, so that normal air pressure fluctuation caused by temperature change and abnormal air pressure change caused by air leakage are effectively distinguished, automatic identification and early warning of micro leakage of the inflatable film structure are realized, and the safety and reliability of the structure operation are improved. In order to achieve the above purpose, the technical solution of the invention is that an inflatable film structure air pressure anomaly monitoring method for distinguishing temperature change and air leakage comprises the following steps: Step 1 comprises the steps of establishing a geometric structure of the inflatable film and establishing air inside according to an actual structure of the inflatable film structure in ANSYS APDL modeling software, and defining corresponding material properties, wherein the geometric dimension parameters comprise the outline dimension of the film structure, the film surface thickness and the air dimension, and the material property parame