Simply Supported Beam Damage Identification Using Rotation Angles
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Solution Overview
Problem
The static identification method for damage in simply supported beam structures requires a known static load, which is restrictive and hinders its widespread application, as it necessitates closed traffic and precise load calibration.
Innovation Solution
A method that segments a simply supported beam and uses measured sectional rotation angles to establish relative flexural rigidities, allowing for damage identification without prior load calibration, by applying a concentrated load and employing a finite element numerical model to determine damage location and extent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the static identification method uses a known static load to ensure high measurement accuracy and reliable identification results, then the measurement precision and reliability are improved, but the application conditions become more restrictive requiring closed traffic and precise load calibration
Solution Approach 1:
The patent changes the parameter from absolute load value to load ratio (P1/P2). By using the ratio of two different loads applied at different positions, the method eliminates the need for precise load calibration while maintaining identification accuracy. The flexural rigidity is determined through the relationship between rotation angles and load ratios, making the system adaptable to open traffic conditions.
Solution Approach 2:
The patent introduces rotation angles at different sections as intermediary parameters. Instead of directly measuring load or deflection, the method uses rotation angles (θ1, θ2, θ3, θ4) at four sections of the beam as intermediate measurements that relate both loads P1 and P2. These intermediary parameters enable the determination of flexural rigidity without requiring precise knowledge of the absolute load values.
2Reliability
If the static identification method requires precise load calibration to achieve reliable identification results, then the reliability is improved, but the operation complexity and workload increase
Solution Approach 1:
The patent transforms the requirement from precise load calibration to simple load application. By using the ratio of two loads (P1/P2) rather than absolute load values, the method maintains reliable identification results while significantly simplifying operation. The loads only need to be applied at specified positions without requiring precise magnitude control, making the operation much easier.
Solution Approach 2:
The method uses the structure's own response (rotation angles) under different loading conditions to self-determine its flexural rigidity. The four rotation angle measurements under loads P1 and P2 provide sufficient information to calculate the flexural rigidity without external calibration, making the system self-sufficient and easier to operate.
3Measurement precision
If the static identification method applies a certain static load to measure response data for damage identification, then the identification accuracy is improved, but the application becomes restrictive requiring closed traffic conditions
Solution Approach 1:
The patent changes from using absolute load values to using load ratios and relative measurements. By applying loads at two different positions (P1 at position a, P2 at position b) and measuring the ratio of resulting rotation angles, the method achieves accurate damage identification without requiring controlled closed traffic conditions, thus improving adaptability to real-world open traffic scenarios.
Solution Approach 2:
The patent divides the beam into multiple sections and measures rotation angles at four specific sections (θ1, θ2, θ3, θ4). This segmentation approach allows the method to capture the structural response at multiple locations, enabling accurate damage identification while using simple load applications that can be performed under various traffic conditions including open traffic.
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
Enables accurate and convenient static identification of damage in simply supported beam structures under uncertain loads, reducing application conditions and workload, with universal applicability across different materials and geometrical shapes.
Implementation Method 1
arranging a tilt angle sensor at a segment section of the beam structure and at sections of fulcrums at both ends of the beam structure, where the tilt angle sensor is used to measure a rotation angle at which the beam body rotates around a horizontal axis
Implementation Method 2
a simply supported beam structure... under the action of a load... the relationships between key measured sectional rotation angles and the flexural rigidities of segments of a structure
Data Source
AI summary
The present disclosure provides a method for static identification of damage to a simply supported beam under an uncertain load. In this identification method, a beam body is first segmented, and the relationships between key measured sectional rotation angles and the flexural rigidities of segments of a structure under the action of a load are established by using a mechanics principle; then, an applied static load is removed by means of a division operation, and the relative relationships between the flexural rigidities of the segments of the structure are obtained; and finally, these relative relationships are compared with the corresponding relative relationships when the structure is not damaged, so as to determine the position of damage to the structure and assess the amount of damage, such that the static identification for damage to a simply supported beam structure can be completed without calibrating a load in advance.