Related Experiment Video
Updated: Feb 4, 2026

Full-field Strain Measurements for Microstructurally Small Fatigue Crack Propagation Using Digital Image Correlation Method
Published on: January 16, 2019
Dynamic Visualization of Stress/Strain Distribution and Fatigue Crack Propagation by an Organic Mechanoresponsive AIE
Zijie Qiu1,2,3, Weijun Zhao2,3, Mingkui Cao1
1School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China.
Abstract:
Stress exists ubiquitously and is critically important for the manufacturing industry. Due to the ultrasensitive mechanoresponse of the emission of 1,1,2,2,-tetrakis(4-nitrophenyl)ethane (TPE-4N), a luminogen with aggregation-induced emission characteristics, the visualization of stress/strain distributions on metal specimens with a pure organic fluorescent material is achieved. Such a fluorescence mapping method enjoys the merits of simple setup, real-time, full-field, on-site, and direct visualization. Surface analysis shows that TPE-4N can form a nonfluorescent, crystalline uniform film on the metal surface, which cracks into fluorescent amorphous fragments upon mechanical force. Therefore, the invisible information of the stress/strain distribution of the metal specimens are transformed to visible fluorescent signals, which generally matches well but provides more details than software simulation. Remarkably, fatigue crack propagation in stainless steel and aluminum alloy can be observed and predicted clearly, further demonstrating the ultrasensitivity and practicability of TPE-4N.
Related Concept Videos
Problem Solving on Stress and Strain
Stress-Strain Diagram
True Stress and True Strain
In contrast, true stress offers a more precise portrayal. It is computed by dividing the...
Stress-Strain Diagram - Ductile Materials
Elastic Strain Energy for Normal Stresses
If...
Elastic Strain Energy for Shearing Stresses

