Super-Large Deformation Measurement via Mark Point Tracking
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Solution Overview
Problem
Current methods lack a unified measurement standard for super-large deformation, making objective measurement and comparison of deformation degrees impossible, which restricts the application of such materials in industrial and military fields.
Innovation Solution
A method involving the arrangement of mark points on a plane for image recognition, calculating deformation gradient matrices, and determining elongation, strain, and angular tensors to quantify rotation deformation, allowing for objective measurement of super-large deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement methods are used for super-large deformation, then measurement process is simple, but measurement precision and objectivity are insufficient
Solution Approach 1:
The measurement plane is divided into multiple discrete mark points that can be independently tracked. Each mark point's deformation is measured separately through image recognition, allowing precise local deformation characterization without requiring complex continuous measurement systems.
Solution Approach 2:
Mark points are introduced as intermediary elements to enable measurement. These marks serve as mediators between the deformation field and the measurement system, allowing optical methods to capture deformation information that would otherwise be difficult to quantify objectively.
2Measurement precision
If rotation deformation is not considered, then measurement process is simplified, but measurement completeness and accuracy deteriorate
Solution Approach 1:
The measurement system transitions from static deformation measurement to dynamic deformation measurement by incorporating rotation angles and curvature changes. The deformation gradient matrix and its decomposition capture the time-varying nature of super-large deformation including rotational components.
Solution Approach 2:
Additional deformation parameters (rotation angles, curvature, orthogonal tensor components) are introduced to fully characterize super-large deformation. These parameter changes enable comprehensive description of both tensile and rotational deformation modes without oversimplification.
3Measurement precision
If unified measurement standard is not established, then measurement flexibility is maintained, but measurement objectivity and comparability are lost
Solution Approach 1:
The measurement system is designed to be universally applicable to various super-large deformation scenarios including rubber, biological tissues, and metal forming. The same mark point-based image recognition and deformation gradient calculation methodology can be applied across different materials and deformation modes.
Solution Approach 2:
A standardized set of deformation parameters (deformation gradient matrix, elongation tensor, orthogonal tensor, rotation angle, curvature) is established as the unified measurement standard. These parameters provide objective and comparable measurements across different applications while maintaining measurement flexibility.
Data Source
AI summary
A method includes the steps of arranging mark points for image recognition on a plane of a test piece to be measured; recognizing and recording positions of two-dimensional Cartesian coordinates of each mark point of the test piece to be measured before and after each stretching; and determining a deformation gradient of each mark point and deformation measurement parameters of each mark point through a numerical method, where the deformation measurement parameters include a deformation gradient matrix, an elongation tensor matrix, a finite strain tensor matrix, an orthogonal tensor matrix, an angular tensor matrix, a rotation angle, and a curvature. According to the method, objective measurement of super-large deformation of the plane relating to rotation deformation is achieved.