Acoustic Emission Deterioration Evaluation Across Monitoring Data Gaps
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Solution Overview
Problem
The evaluation accuracy of structure deterioration state decreases during long-term monitoring due to periods without data acquisition using the b-value or improved b-value from amplitude scale-based frequency distribution in acoustic emission methods.
Innovation Solution
A structure evaluation system and method that utilizes a plurality of sensors to detect elastic waves, an acquirer to gather detection information, a calculator to calculate the b-value every predetermined period, and an evaluator to assess the structure's deterioration state by separating trend and seasonality components using an additive regression model.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If long-term monitoring is performed using b-value from acoustic emission method, then early detection of deterioration signs is enabled, but evaluation accuracy decreases when data acquisition is interrupted
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing cumulative event counts and cumulative energy values at each measurement point. When data is interrupted and then resumed, these pre-calculated values are retrieved and used to continue the analysis without requiring complete continuous data, thus maintaining evaluation accuracy despite data gaps.
Solution Approach 2:
The patent implements feedback by using the cumulative event count and cumulative energy from previous measurement points as initial values when monitoring resumes. This feedback mechanism allows the system to continue calculating b-values accurately by incorporating historical information, compensating for periods when data acquisition was interrupted.
2Duration of action of stationary object
If monitoring period is extended to several years for long-term structure health assessment, then deterioration progression can be tracked, but data gaps occur reducing evaluation reliability
Solution Approach 1:
The system performs preliminary calculation and storage of cumulative parameters (event count and energy) at each measurement point during extended monitoring. This allows the system to maintain evaluation accuracy over several years by retrieving these pre-calculated values when monitoring resumes after interruptions, rather than requiring complete continuous data throughout the entire monitoring period.
Solution Approach 2:
The patent changes the approach from requiring continuous raw data to using cumulative parameter values (event count and energy) that can be stored and retrieved. This parameter transformation enables the system to bridge data gaps in long-term monitoring by working with aggregated values rather than requiring every individual measurement point to be continuously available.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Improves the evaluation accuracy of structure deterioration by effectively analyzing long-term trends and seasonal fluctuations in elastic wave data, enabling early detection of damage progression.
Implementation Method 1
an AE sensor using a piezoelectric element
Implementation Method 2
AE is an elastic wave generated by the progress of cracks in the material
Data Source
Figure 1
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Figure 4~5
AI summary
According to one embodiment, a structure evaluation system includes a plurality of sensors, an acquirer, a calculator, and an evaluator. The plurality of sensors detects elastic waves generated from the structure. The acquirer acquires detection information for an evaluation target period in which information on at least an amplitude of each elastic wave detected by each of the plurality of sensors is associated with time information on the time when each elastic wave is detected. The calculator calculates an evaluation value, which is a slope of an amplitude scale-based frequency distribution of elastic waves, every predetermined period based on the acquired detection information for the evaluation target period. The evaluator evaluates a deterioration state of the structure based on the time-series data of each evaluation value calculated every predetermined period.