Research On Allowable Stress Monitoring Of H-beam Web Based On Piezoelectric Ceramics

The stability of H-shaped steel webs is one of the important factors affecting safety during the construction process and subsequent stability of the project.This article studies the stability and ultimate bearing capacity of H-shaped steel webs based on piezoelectric ceramic sensors,and monitors the stability of H-shaped steel webs in real-time.A method for monitoring the stability of H-shaped steel webs using piezoelectric ceramics is proposed,which can be used to study the stability and ultimate bearing capacity of H-shaped steel webs.At present,there are many methods for Structural health monitoring(SHM),including ultrasonic,acoustic emission(AE),image processing,optical fiber sensors and coaxial cable sensors.However,currently,most low-cost research methods are only applicable to structures with simple geometric shapes or restricted areas;However,the localization strategy of acoustic emission sources in actual engineering structures is quite complex.Although the real structure source localization method based on artificial neural networks and the use of distributed sensors(such as intelligent thin film,fiber optic sensors,and binary crack sensors)to monitor the health status of structures are highly accurate and efficient,most of them are computationally expensive.Due to the high cost of the system and sensor probes,most of the above methods are not suitable for real-time applications.Therefore,it is necessary to develop a low-cost real-time monitoring method for the occurrence and development of cracks in reinforced concrete beams.In order to achieve real-time monitoring,sensors must be low-cost and can be integrated with concrete structures.Piezoelectric ceramic materials have been widely used in actuators and sensors for health monitoring due to their advantages of low cost,fast response,and embeddability.At present,there have been some achievements in the research of Structural health monitoring of structures containing H-shaped steel using piezoelectric ceramics,but further research and optimization are still needed in sensor materials,signal processing algorithms,monitoring parameters and other aspects,and the cost of real-time monitoring of structural health under existing research is relatively high,which is difficult to be applied on a large scale.Therefore,it is necessary to develop a low-cost real-time health monitoring method for the occurrence and development of cracks in reinforced concrete beams.In order to achieve real-time monitoring of structures,sensors must be low-cost and embedded inside concrete,integrated with the concrete structure.In recent years,lead zirconate titanate piezoelectric ceramic sensors have been increasingly used for Structural health monitoring of various building structures due to their low cost,wide bandwidth,dual sensing and driving functions,energy collection and strong piezoelectric effects.This article proposes a monitoring method for the ultimate bearing capacity of H-shaped steel webs based on lead zirconate titanate piezoelectric ceramic sensors.This article first introduces the calculation of elastic buckling stress under the theory of H-shaped steel webs,and then analyzes the actual elastic-plastic buckling stress of H-shaped steel webs by adding various initial defects.Furthermore,the ultimate bearing capacity of H-shaped steel webs is calculated,providing a theoretical basis for the stability test of webs and ANSYS finite element simulation in the following text.The simulation results can be compared with the theoretical formula,Further verify the accuracy of the experiment.Subsequently,a comparative experiment was conducted using two sets of electro-hydraulic servo testing machines to simulate the repeated loading response.The relationship between the frequency amplitude received by the PZT piezoelectric ceramic sensor and the load and height of the H-shaped steel web was quantitatively discussed using the method of controlling variables.At the same time,the influence of adding slant support to H-beam web on the stability and ultimate bearing capacity of H-beam web is discussed.In addition,an energy index has been developed to quantitatively evaluate the attenuation of stress wave energy.This energy index can be used to estimate the stress and ultimate bearing capacity of H-shaped steel webs,and provide real-time monitoring data for early warning and stress assessment.Finally,the modeled specimens were analyzed using ANSYS software to analyze the deformation of various web elements.Through calculation and analysis,the feasibility of the real-time monitoring method for H-shaped steel web stability proposed in the previous text was verified,and an example of real-time monitoring using this method in practical engineering(intelligent aggregate SA)was provided.Based on this,this article proposes an innovative method based on piezoelectric ceramic sensors to simulate repeated loading response through an electro-hydraulic servo testing machine.At the same time,a quantitative evaluation of the stress on the H-beam web,namely the energy index,was also proposed.By observing the critical point where the signal amplitude gradually increases to decrease,and then detecting the ultimate bearing capacity that the H-beam can withstand,it can be determined whether there is instability failure in the H-beam.This can be used to monitor the stress of H-shaped steel webs during the whole construction process,and can also be used for subsequent real-time Structural health monitoring to determine whether the structure will be damaged due to reaching the ultimate bearing capacity of the structure due to other reasons in the future.Real time monitoring of H-shaped steel webs provides important data support for optimizing structural design,enabling timely detection of structural damage or fatigue,and taking corresponding maintenance and reinforcement measures to ensure the safety of the structure.