CN-122016937-A - Concrete column damage evaluation method based on piezoelectric sensing technology

CN122016937ACN 122016937 ACN122016937 ACN 122016937ACN-122016937-A

Abstract

The invention provides a concrete column damage evaluation method based on a piezoelectric sensing technology, which comprises the steps of embedding a plurality of piezoelectric sensors in the most sensitive damage section of a column body before pouring the concrete column to be monitored, collecting charge signals output by the piezoelectric sensors in the process of external load action of the concrete column to be monitored, respectively converting the charge signals into concrete axial strain at the position corresponding to the sensor arrangement position, calculating concrete axial stress at the corresponding position based on the concrete axial strain, calculating concrete compression damage factors of the corresponding monitoring points according to the concrete axial stress and axial strain data of the monitoring points, calculating the average value of the concrete compression damage factors of all the monitoring points on the most sensitive damage section, taking the average value as an average damage index of the section, taking the average damage index of the section as an evaluation index of the concrete column to be monitored from material damage to integral damage of a member, and judging the integral damage grade of the concrete column to be monitored.

Inventors

XIANG HONG
LIU QIYUAN
HU SHIYI
LIU XIUPING
LI CONG
LI SITONG
LIN ZEKANG
Huang Yubinhui

Assignees

福建理工大学

Dates

Publication Date: 20260512
Application Date: 20260311

Claims (10)

1. The concrete column damage evaluation method based on the piezoelectric sensing technology is characterized by comprising the following steps of: Before casting the concrete column to be monitored, embedding a plurality of piezoelectric sensors in the most sensitive damage section of the column; Collecting charge signals output by each piezoelectric sensor in the process of external load action of the concrete column to be monitored; Respectively converting each charge signal into concrete axial strain at a corresponding sensor arrangement position, and calculating concrete axial stress at a corresponding position based on the concrete axial strain; According to the concrete axial stress and axial strain data of each monitoring point, calculating a concrete compression damage factor of the corresponding monitoring point, and ignoring the influence of concrete tension damage on an evaluation result; Calculating the average value of the concrete compression damage factors of all monitoring points on the most sensitive damage section, and taking the average value as the average damage index of the section; and taking the section average damage index as an evaluation index from material damage to overall member damage of the concrete column to be monitored, and judging the overall damage grade of the concrete column to be monitored.
2. The method for evaluating concrete column damage based on the piezoelectric sensing technology as claimed in claim 1, wherein the height range of the most sensitive damage section is 0.3 from the bottom of the concrete column to be monitored To 0.6 Wherein The side length of the section of the concrete column to be monitored.
3. The concrete column damage evaluation method based on the piezoelectric sensing technology is characterized in that the process of converting charge signals into concrete axial strain and axial stress is that an external calibration test is carried out on a piezoelectric sensor before embedding to obtain calibration parameters of the sensor, then the concrete axial strain at a corresponding position is calculated by combining the calibration parameters with the acquired charge signals and an embedded environment correction factor, and finally the concrete axial stress at the corresponding position is obtained through conversion according to the concrete axial strain and an adaptive concrete constitutive model.
4. The concrete column damage evaluation method based on the piezoelectric sensing technology as claimed in claim 3, wherein the pre-buried environment correction factor is used for correcting the medium and boundary constraint difference between the sensor pre-buried inside the concrete and the external calibration environment, and the fixed value is 1.1.
5. The concrete column damage evaluation method based on the piezoelectric sensing technology according to claim 1, wherein the method comprises the following steps: the calculation formula of the concrete compression damage factor is as follows: Wherein, the Is a factor of the compressive damage of the concrete, =0 Corresponds to the concrete lossless state, =1 Corresponds to a concrete complete failure state; is the damage elastic strain of the concrete; the nondestructive elastic modulus of the concrete material; For nominal stresses of the concrete without considering the damaging effects, To take into account the actual stresses of the concrete after the damaging effect.
6. The method for evaluating damage to the concrete column based on the piezoelectric sensing technology as claimed in claim 1, wherein the piezoelectric sensors are symmetrically and uniformly arranged along the section of the concrete column to be monitored, and the number of the piezoelectric sensors is not less than 5, and the piezoelectric sensors cover different areas from the edge of the section to the inside.
7. The method for evaluating the damage of the concrete column based on the piezoelectric sensing technology, which is characterized in that a damage threshold interval for judging the damage level of the concrete column is determined by adopting a Col Mo Geluo F-Schmidt test to obtain a damage value normal distribution curve at each performance key point of macroscopic plastic development of the concrete column based on test and numerical simulation statistical results, taking an upper limit value of 95% confidence coefficient of each performance key point corresponding to the normal distribution function as a critical damage value of the performance point, and forming damage threshold intervals corresponding to different performance stages.
8. The method for evaluating the damage of the concrete column based on the piezoelectric sensing technology, which is characterized by comprising the steps of comparing the section average damage index with the occurrence time of a macroscopic plastic development key point of the concrete column when the section average damage index is used as an overall damage evaluation index, and establishing the correlation between the section average damage index and the plastic development and performance state of the concrete column, wherein the macroscopic plastic development key point of the concrete column comprises concrete cracking, longitudinal rib yielding, section steel yielding and concrete crushing.
9. The method for evaluating the damage of the concrete column based on the piezoelectric sensing technology as claimed in claim 1, wherein the concrete column to be monitored is a steel reinforced concrete column or a reinforced concrete column, and the steel reinforced concrete column comprises an asymmetric steel-matched steel reinforced concrete column.
10. The concrete column damage evaluation system is characterized by comprising a piezoelectric sensing module, a data acquisition module, a data processing module and a damage evaluation module, wherein the piezoelectric sensing module comprises a plurality of piezoelectric sensors which are embedded in the most sensitive damage section of a concrete column to be monitored and are used for acquiring charge signals in the loading process of the concrete column, the data acquisition module is in communication connection with the piezoelectric sensing module and is used for acquiring the charge signals output by the piezoelectric sensors, the data processing module is in communication connection with the data acquisition module and is used for converting the charge signals into concrete axial strain and axial stress and calculating concrete compression damage factors and section average damage indexes of all monitoring points, and the damage evaluation module is in communication connection with the data processing module and is used for judging the overall damage grade of the concrete column by taking the section average damage indexes as the overall damage evaluation indexes of the concrete column.

Description

Concrete column damage evaluation method based on piezoelectric sensing technology Technical Field The invention belongs to the technical field of health monitoring of civil engineering structures, and particularly relates to a concrete column damage evaluation method based on a piezoelectric sensing technology, which is particularly suitable for damage monitoring and performance evaluation of a section steel concrete column and other reinforced concrete members under the action of load. Background The current widely adopted concrete column damage assessment method mainly comprises the steps of carrying out seismic damage assessment on a component level, generally not relating to a damage evolution process of a material level, and not being capable of deducing internal force and deformation time of a component through material damage, mainly providing quantitative indexes of performance from macroscopic angles such as deformation, strength and rigidity degradation, energy and the like, and establishing a seismic damage model, wherein the typical representation is a Park-Ang damage model and an improved model thereof. Although the method is widely applied, the damage evolution process of the material layer is difficult to directly reflect, and core evaluation indexes such as internal force, energy consumption and the like are difficult to obtain in actual engineering. The nature of the structural and component damage is the damage of the constituent materials, and the performance states of the structural and component are mastered from the material level, so that the structural and component damage has theoretical congenital superiority. The existing component integral damage evaluation method based on the material damage information can only be applied to a numerical simulation scene, and how to effectively extract and quantitatively evaluate the material damage information in the test and actual engineering becomes a core technical difficulty in the field. The existing method for evaluating the damage of the steel reinforced concrete column is also concentrated on the component level, and the component level damage model established based on the test result can macroscopically reflect the damage degree of the component, but the model is established based on macroscopic indexes such as load, displacement, energy and the like measured by the test, and core evaluation parameters are difficult to acquire in actual engineering. The existing component hierarchical macroscopic models are built based on statistical fitting of the overall macroscopic mechanical response of the component, the damage accumulation process inside the related materials cannot be directly revealed, and the theoretical basis is not tightly connected with the component destruction mechanism. Disclosure of Invention Aiming at the defects and shortcomings in the prior art, the invention provides a concrete column damage evaluation method and system based on an intelligent piezoelectric sensing technology, which mainly solve the problems that the existing concrete column damage evaluation scheme is concentrated on a macroscopic level of a component and cannot be associated with a damage evolution process in a material, core evaluation parameters are difficult to effectively acquire in actual engineering, and a damage evaluation method of the material level is difficult to fall to the applied industry pain point. The method comprises the steps of embedding a plurality of piezoelectric sensors in the most sensitive damage section with the length of 0.3 to 0.6 times of the section side length from the bottom of a concrete column before pouring the concrete column, collecting charge signals output by the sensors in the process of the external load action of the concrete column, converting the charge signals into concrete axial stress and strain data corresponding to the arrangement positions, converting the concrete stress and strain data of each monitoring point into corresponding compression damage factors based on strain equivalent assumptions in continuous medium damage mechanics, taking the average value of all the monitoring point damage factors in the section as a section average damage index, taking the average value as a core evaluation basis of the integral damage of the concrete column, and combining damage threshold intervals corresponding to different performance stages determined by statistical inspection to finish the damage grade judgment of the concrete column. The invention constructs a multi-level cross-scale damage evaluation system of the material-section-component, realizes direct, accurate and real-time monitoring of hidden damage in the concrete, does not need to depend on macroscopic mechanical parameters which are difficult to obtain in engineering, has high consistency with a classical component damage model, has tight connection between a theoretical foundation and a component damage mechanism, can provide quantitative