DIC Bridge Stress Measurement via Phosphor Speckle Imaging
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Solution Overview
Problem
Traditional bridge stress detection methods are risky, difficult, and inaccurate, requiring significant manpower and failing to provide reliable data for bridge maintenance and reinforcement.
Innovation Solution
An automatic test system utilizing DIC technology, comprising a camera, phosphor spraying device, and computer, which forms speckles on a bridge's concrete beam and analyzes images to generate a time history diagram of stress, reducing human error and increasing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional bridge stress detection methods are used, then measurement can be performed, but measurement precision and reliability are poor
Solution Approach 1:
The patent replaces traditional mechanical contact-based stress detection methods with an optical imaging system. A camera captures images of phosphor-coated speckles on the bridge surface, and a computer analyzes these images to calculate stress values. This substitution of mechanical systems with optical and computational systems eliminates contact risks, improves measurement precision, and enhances detection reliability.
Solution Approach 2:
The patent utilizes phosphor coating that changes color or fluorescence properties in response to stress. The phosphor is sprayed on the bridge surface to form speckles, and under specific lighting conditions, the phosphor's optical properties change with stress, allowing the camera to capture stress-induced variations and enabling precise non-contact stress measurement.
2Productivity
If traditional detection methods are used, then stress data can be obtained, but the process is risky and requires significant manpower
Solution Approach 1:
The system enables self-service detection by automating the stress measurement process. The camera automatically captures images, the computer automatically analyzes the speckle patterns, and stress values are automatically calculated and displayed. This eliminates the need for manual measurement operations, reduces manpower requirements, and improves detection efficiency while making the process safer and easier to operate.
Solution Approach 2:
The patent replaces manual mechanical detection operations with an automated optical system. Instead of workers physically measuring stress points, the camera and computer system automatically perform detection, analysis, and calculation, significantly improving productivity and reducing operational complexity.
3Measurement precision
If traditional stress detection is performed, then some stress data can be collected, but the accuracy is insufficient for reliable maintenance decisions
Solution Approach 1:
The phosphor coating's stress-dependent optical properties enable high-precision stress measurement. As stress varies, the phosphor's color or fluorescence characteristics change, providing rich information that the camera captures. This allows accurate stress data collection without information loss, enabling reliable maintenance decisions.
Solution Approach 2:
The system creates a visual copy of the stress state through phosphor speckle patterns. The phosphor coating replicates stress information in optical form, which the camera captures as images. This copying process preserves stress information accurately, allowing detailed analysis and preventing information loss that would occur with traditional measurement methods.
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 achieves high-efficiency, high-speed, and high-accuracy stress measurement, saving labor costs and providing comprehensive data for bridge construction and maintenance, especially for areas inaccessible by traditional methods.
Implementation Method 1
the phosphor spraying device is used to spray phosphor on a web of the box-shaped concrete beam to form speckles of varying light and shade
Implementation Method 2
the camera is slidably connected to the sliding rail through a bracket, and is used to photograph the speckles and transmit a speckle image to the computer
Data Source
AI summary
The present disclosure provides an automatic test system for actual stress of a bridge based on DIC technology, where the system includes a camera, a phosphor spraying device, a computer, and a sliding rail; the sliding rail is arranged on both sides of an upper wing of a box-shaped concrete beam; the phosphor spraying device is used to spray phosphor on a web of the box-shaped concrete beam to form speckles of varying light and shade; the camera is slidably connected to the sliding rail through a bracket, and is used to photograph the speckles and transmit a speckle image to the computer; and the computer is used to analyze and process the speckle image taken by the camera and generate a time history diagram of stress.