RU2013124375A

RU2013124375A - ACOUSTIC AND EMISSION METHOD FOR DIAGNOSTIC OF METAL STRUCTURES

Info

Publication number: RU2013124375A
Application number: RU2013124375/28A
Authority: RU
Inventors: Людмила Николаевна Степанова; Сергей Алексеевич Бехер; Алексей Леонидович Бобров
Priority date: 2013-05-27
Filing date: 2013-05-27
Publication date: 2014-12-10
Also published as: RU2537747C1

Abstract

1. Акустико-эмиссионный способ диагностирования металлических конструкций, включающий прием, регистрацию и оценку параметров сигналов акустической эмиссии в момент нагружения конструкции, оцифровку акустических сигналов, их предварительную обработку, фильтрацию помех, отличающийся тем, что сначала устанавливают критические значения нагрузки Pи коэффициента регрессии k, характеризующего изменение числа сигналов акустической эмиссии к изменению нагрузки для бездефектной конструкции, затем конструкцию нагружают до значения нагрузки, превышающей рабочую на (5…10) %, регистрируют при этом число сигналов и нагрузку линейного участка стационарной акустической эмиссии, регистрируют при этом коэффициент регрессии k, после чего конструкцию нагружают циклической нагрузкой, амплитудное значение которой повышают постепенно на (2…5) %, и при достижении превышения на (15…20) % рабочей нагрузки нагружение прекращают, если в процессе контроля k<kто конструкцию считают бездефектной, а при значении k>kконструкцию бракуют.2. Способ по п.1, отличающийся тем, что критический коэффициент регрессии определяют по формуле, где ΔP, ΔN- соответственно изменения нагрузки и числа сигналов акустической эмиссии бездефектной конструкции.3. Способ по п.1, отличающийся тем, что скорость и частоту нагружения регулируют в зависимости от регистрируемой активности и затухания сигналов акустической эмиссии таким образом, чтобы количество не регистрируемых сигналов не превышало 1-5%.1. An acoustic emission method for diagnosing metal structures, including receiving, recording and evaluating parameters of acoustic emission signals at the time of loading of a structure, digitizing acoustic signals, their preliminary processing, filtering interference, characterized in that the critical load values P and the regression coefficient k are first set, characterizing the change in the number of acoustic emission signals to a change in load for a defect-free structure, then the structure is loaded to a load value, exceeding the working one by (5 ... 10)%, the number of signals and the load of the linear portion of the stationary acoustic emission are recorded, the regression coefficient k is recorded, after which the structure is loaded with a cyclic load, the amplitude value of which is gradually increased by (2 ... 5)%, and when an excess of (15 ... 20)% of the workload is reached, loading is stopped if, during the control process k <k, the structure is considered defect-free, and if k> k, the structure is rejected. 2. The method according to claim 1, characterized in that the critical regression coefficient is determined by the formula, where ΔP, ΔN are the changes in the load and the number of acoustic emission signals of a defect-free design. The method according to claim 1, characterized in that the speed and frequency of loading is regulated depending on the recorded activity and attenuation of the acoustic emission signals so that the number of unrecorded signals does not exceed 1-5%.

Claims

1. The acoustic emission method for diagnosing metal structures, including receiving, recording and evaluating the parameters of acoustic emission signals at the time of loading the structure, digitizing acoustic signals, their preliminary processing, filtering interference, characterized in that the critical load values P _cr and the regression coefficient are first set k _cr characterizing a change in the number of acoustic emission signals to a change in load for a defect-free design, then the design is loaded to a load value loads exceeding the working one by (5 ... 10)%, in this case, the number of signals and the load of the linear section of the stationary acoustic emission are recorded, the regression coefficient k _{0 is} recorded, after which the structure is loaded with a cyclic load, the amplitude value of which is gradually increased by (2 ... 5 )%, and when the excess of (15 ... 20)% of the workload is reached, loading is stopped, if during the control process k ₀ <k _cr then the structure is considered to be defect-free, and if k ₀ > k _{cr, the} structure is rejected.

2. The method according to claim 1, characterized in that the critical regression coefficient is determined by the formula

k_{to R} = (3 .. 5) \cdot \frac{Δ N_{B}}{Δ P_{B}}

, where ΔP _B , ΔN _B are, respectively, changes in the load and the number of acoustic emission signals of a defect-free design.

3. The method according to claim 1, characterized in that the speed and frequency of loading is regulated depending on the recorded activity and attenuation of the acoustic emission signals so that the number of unrecorded signals does not exceed 1-5%.