Elastic Wave Structure Evaluation With Distance-Based Threshold Correction
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Solution Overview
Problem
Existing structure evaluation systems face challenges in accurately determining the deteriorated state of structures due to non-uniform distribution of elastic wave sources caused by uneven sensor placement and non-uniform external impacts, leading to incorrect evaluations.
Innovation Solution
A structure evaluation system that divides the measurement region into multiple areas based on the distance between the elastic wave source and the 4th hit sensor, sets different threshold values for each area, and corrects the elastic wave source density distribution using a correction coefficient to ensure uniformity, thereby improving evaluation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensors are installed on the structure surface to detect elastic waves, then damage detection capability is improved, but evaluation accuracy deteriorates due to non-uniform elastic wave source distribution caused by sensor disposition and external impact variations
Solution Approach 1:
The patent applies parameter changes by introducing a correction coefficient that varies based on the distance from the elastic wave source to the sensor. This coefficient adjusts the threshold values for elastic wave detection, compensating for the non-uniform distribution caused by sensor disposition and external impact variations. By dynamically changing the detection parameters (threshold values) according to distance, the system maintains consistent damage detection capability across different locations while correcting for positional biases.
2Stability of the object's composition
If uniform impact is imparted to the structure from outside, then elastic wave generation is improved, but non-uniform sensor disposition causes non-uniform detection distribution, leading to incorrect deterioration evaluation
Solution Approach 1:
The patent applies local quality by implementing location-specific threshold values based on the distance from each sensor to the elastic wave source. Instead of using a single uniform threshold across all sensors, the system adjusts the detection threshold locally for each sensor according to its specific geometric relationship with the wave source. This local adaptation compensates for the non-uniform sensor disposition and ensures that each sensor operates with optimal sensitivity for its specific position, thereby achieving uniform detection distribution across the entire structure surface.
3Loss of information
If position locator derives wave source distribution from sensor signals, then damage location capability is improved, but non-uniform distribution from sensor disposition causes incorrect damage identification
Solution Approach 1:
The patent applies feedback by using the derived wave source distribution information to calculate correction coefficients that are then fed back into the detection system. The position locator not only determines wave source locations but also generates correction data based on the observed distribution patterns. This correction information is fed back to adjust the detection thresholds, creating a closed-loop system that continuously refines the accuracy of damage position identification by compensating for systematic biases introduced by sensor disposition.
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
The system enhances the accuracy of structure evaluation by ensuring uniformity in elastic wave source density, preventing sound structures from being erroneously identified as deteriorated, and accurately identifying actual deterioration regions.
Implementation Method 1
By installing a sensor such as an AE sensor on the surface of a structure such as a bridge, it is possible to detect an elastic wave generated from a damaged part inside the structure.
Data Source
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AI summary
A structure evaluation system according to an embodiment includes a plurality of sensors, a position locator, and an evaluator. The plurality of sensors detect elastic waves. The position locator locates positions of elastic wave sources by using the elastic waves among the plurality of elastic waves respectively detected by the plurality of sensors having an amplitude exceeding a threshold value determined according to positions of the sources of the plurality of elastic waves and the positions of the plurality of disposed sensors. The evaluator evaluates a deteriorated state of the structure on the basis of results of the position locating of the elastic wave sources which is performed by the position locator.