Stress and strain amount distribution display method, device, and program
Inventors
Assignees
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Publication Number
US-12135312-B2
Publication Date
2024-11-05
Expiration Date
Abstract
A method of displaying stress distribution on a sample surface includes: step S4 of capturing images of the sample surface before loading, during the loading, and after unloading; step S5 of measuring a first strain amount for each pixel position based on correlation between the image before the loading and the image after the unloading; step S6 of measuring a second strain amount for each pixel position based on correlation between the image before the loading and the image during the loading; step S7 of calculating stress for each pixel position based on the difference between the first strain amount and the second strain amount; and step S8 of displaying the distribution of the calculated stress at each pixel position.
Core Innovation
A stress distribution is displayed on a sample surface while repeatedly loading and unloading the sample by capturing images of the sample surface before loading, during the loading, and after unloading. For each pixel position, a first strain amount is measured based on correlation between the image before the loading and the image after the unloading, and a second strain amount is measured based on correlation between the image before the loading and the image during the loading.
Stress for each pixel position is calculated based on the difference between the first strain amount and the second strain amount, and the distribution of the calculated stress at each pixel position is displayed. In repeated loading and unloading, the difference in stress displayed at the same pixel position between stress distribution obtained by the last loading and unloading and stress distribution obtained by the current loading and unloading is calculated, and a pixel position at which the difference is equal to or greater than a predetermined threshold value is displayed.
The stress distribution is further processed by displaying the difference in stress in the form of frequency distribution for each pixel position according to predetermined stress value ranges. In addition, a difference in stress of the entire material between stress distribution obtained by the last loading and unloading and stress distribution obtained by the current loading and unloading is calculated, and the difference in stress of the entire material is displayed in the form of frequency distribution for each unloading.
Claims Coverage
The independent claims cover 5 distinct aspects of the same concept: per-pixel stress distribution display with cycle-to-cycle stress-difference threshold highlighting, per-pixel stress-difference frequency distribution over predetermined stress value ranges, entire-material stress-difference frequency distribution for each unloading, detecting a pixel based on a correlation threshold during loading, and corresponding device and program-medium implementations. These claims define inventive features centered on correlation-based first and second strain measurement and stress calculation from their difference, together with repeated loading/unloading comparisons.
Correlation-based first and second strain measurement before, during, and after loading
Measuring a first strain amount for each pixel position based on correlation between the image before the loading and the image after the unloading, and measuring a second strain amount for each pixel position based on correlation between the image before the loading and the image during the loading.
Per-pixel stress calculation from the difference between strain amounts
Calculating stress for each pixel position based on the difference between the first strain amount and the second strain amount, and displaying the distribution of the calculated stress at each pixel position.
Cycle-to-cycle stress difference threshold pixel highlighting
Calculating the difference in stress displayed at the same pixel position between stress distribution obtained by the last loading and unloading and stress distribution obtained by the current loading and unloading, and displaying a pixel position at which the difference is equal to or greater than a predetermined threshold value.
Per-pixel stress difference displayed as frequency distribution over predetermined stress value ranges
Displaying the difference in stress in the form of frequency distribution for each pixel position according to predetermined stress value ranges.
Entire-material stress difference displayed as frequency distribution for each unloading
Calculating the difference in stress of the entire material between stress distribution obtained by the last loading and unloading and stress distribution obtained by the current loading and unloading, and displaying the difference in stress of the entire material in the form of frequency distribution for each unloading.
Correlation-threshold pixel detection during loading
Detecting a pixel at which the maximum value of the correlation between the image before the loading and the image during the loading is equal to or less than the predetermined threshold value and displaying the position of the detected pixel in the measuring a second strain amount.
Device with image capture, correlation-based strain measurement, stress calculation, and display
An image-capturing unit that captures images of a sample surface before loading, during the loading, and after unloading; a strain amount measurement unit that measures a first strain amount for each pixel position based on correlation between the image before the loading and the image after the unloading and measures a second strain amount for each pixel position based on correlation between the image before the loading and the image during the loading; a stress calculation unit that calculates stress for each pixel position based on the difference between the first strain amount and the second strain amount and the difference in stress displayed at the same pixel position between stress distribution obtained by the last loading and unloading and stress distribution obtained by the current loading and unloading; and a display unit that displays the distribution of the calculated stress at each pixel position and a pixel position at which the difference is equal to or greater than a predetermined threshold value.
Non-transitory computer readable medium with program modules for stress distribution display
Computer-implemented modules including a module that captures images of a sample surface before loading, during the loading, and after unloading; a module that measures a first strain amount for each pixel position based on correlation between the image before the loading and the image after the unloading; a module that measures a second strain amount for each pixel position based on correlation between the image before the loading and the image during the loading; a module that calculates stress for each pixel position based on the difference between the first strain amount and the second strain amount and the difference in stress displayed at the same pixel position between stress distribution obtained by the last loading and unloading and stress distribution obtained by the current loading and unloading; and a module that displays the distribution of the calculated stress at each pixel position and a pixel position at which the difference is equal to or greater than a predetermined threshold value.
Across the independent claims, the central inventive concept is correlation-based per-pixel measurement of a first strain amount (pre vs after unloading) and a second strain amount (pre vs during loading), followed by per-pixel stress calculation from the difference between these strain amounts and display of the resulting stress distribution. The claims further distinguish outputs by adding cycle-to-cycle stress difference threshold pixel highlighting, per-pixel stress-difference frequency distribution over predetermined stress value ranges, entire-material stress-difference frequency distribution for each unloading, and correlation-threshold pixel detection during loading, together with corresponding device and computer-readable-medium implementations.
Stated Advantages
Documented Applications
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