Microscale Mechanical Testing Imaging for Wide-Strain Deformation Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for characterizing mechanical deformation at microscale, such as SEM and DIC, are limited by low resolution, high cost, interference from speckle patterns, and inability to operate continuously during loading, making it difficult to analyze the influence of microstructural features on deformation.
Innovation Solution
A mechanical testing system using an optical-based imaging platform with closed-loop control and automated adjustment devices to maintain focus and field of view, combined with a controller for continuous image processing and analysis, enabling panoramic imaging and quantification of local deformations like strain fields and crack propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SEM is used for in-situ mechanical testing, then high resolution and greater magnification are achieved, but field of view is limited and image quality drops substantially at lower magnifications
Solution Approach 1:
The patent replaces SEM with an optical-based imaging platform (microscope) that uses light instead of electrons for imaging. This substitution enables a larger field of view while maintaining sufficient resolution for microstructural feature analysis, directly resolving the contradiction between resolution and field of view in SEM systems.
Solution Approach 2:
The patent changes the imaging parameters by operating the optical microscope at appropriate magnifications and using techniques like focus stacking and image processing to achieve both high resolution and large field of view. This allows capturing microstructural features (grains, sub-grain structures) that fall within the imaging capabilities of optical microscopy.
2Measurement precision
If SEM is used for in-situ mechanical testing, then high resolution imaging is achieved, but testing is more time consuming and requires intermittent pauses for scanning
Solution Approach 1:
The patent substitutes the slow scanning process of SEM with rapid optical imaging capable of capturing deformation evolution at high frame rates. This enables continuous monitoring of deformation processes without intermittent pauses, significantly improving testing productivity while maintaining imaging resolution.
Solution Approach 2:
The optical-based system enables continuous imaging throughout the mechanical testing process, allowing uninterrupted capture of deformation evolution. This continuous observation capability eliminates the need to pause loading for scanning, directly improving productivity while maintaining measurement precision.
3Area of stationary object
If optical imaging is used, then larger field of view is achieved, but depth of field is low limiting imaging to maximum of 1% macroscopic strain
Solution Approach 1:
The patent employs dynamic focus adjustment and image processing techniques that adapt to changing focus conditions during deformation. The system can track features through focus changes and reconstruct accurate deformation measurements even when depth of field is limited, extending the measurable strain range while maintaining large field of view.
Solution Approach 2:
The patent uses digital image processing algorithms as intermediaries to bridge the gap between limited depth of field and extended strain measurement range. Techniques like focus stacking and computational methods reconstruct accurate deformation fields from images taken at different focus positions, enabling measurement of larger strains while maintaining optical microscopy's advantage of large field of view.
4Measurement precision
If DIC is used for quantitative deformation analysis, then deformation can be quantitively determined, but speckle patterns obscure visibility of underlying microstructural features
Solution Approach 1:
The patent extracts and removes the speckle pattern application step from the testing methodology. By using the natural microstructural features (grains, sub-grain structures) of the material surface as the tracking markers, the system eliminates the need for artificial speckle patterns that obscure microstructural features, while still enabling quantitative deformation analysis.
Solution Approach 2:
The patent utilizes the inherent optical contrast and visual characteristics of microstructural features (different grain orientations, sub-grain structures) as natural markers for deformation tracking. This approach leverages the natural 'color' and contrast variations in the microstructure to provide both quantitative measurement and visible microstructural information simultaneously.
5Measurement precision
If manual analysis of image frames is performed, then deformation characteristics can be identified, but the process is enormously time-consuming
Solution Approach 1:
The patent implements automated image analysis algorithms that enable the system to analyze and interpret deformation characteristics autonomously without manual intervention. The automated system processes sequences of images to identify deformation evolution, feature tracking, and microstructural changes, eliminating the time-consuming manual analysis process while maintaining measurement precision.
Solution Approach 2:
The patent replaces manual visual analysis with automated computer-based image processing and analysis algorithms. This substitution uses computational methods to automatically identify deformation characteristics, track features, and extract quantitative data from image sequences, dramatically reducing analysis time while maintaining or improving measurement precision.
Data Source
AI summary
A method, apparatus, and software for an in-situ mechanical testing system to characterize heterogeneous deformation at microscale are disclosed. The current intellectual property landscape shows the in-situ mechanical testing of metals and alloys is severely limited to a maximum of about 1% macroscopic strain due to the optical microscopy's low depth of focus. To address this challenge, we disclose a smart imaging system consisting of several novel techniques. The techniques include digitally enhanced effective depth of field, real-time targeting and maintaining of a region of interest to image within the field of view and focus, and a panoramic imaging method to digitally widen the field of view. We also disclose a deformation quantification subsystem to analyze the collected data and quantify deformation characteristics. Finally, an expert system to extract the influence of microstructural features on the elastic-plastic and fracture properties is also disclosed.