Hydrogel fracture experiment: from different stimuli to delayed fratured study (A)

• Main Author: Yip, Zi Hao
• Other Authors: Li Hua
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/168137
• Institution: Nanyang Technological University

Polyacrylamide (PAAm) hydrogel is viewed as a material with immense research potential and market value. PAAm hydrogel has been used in multiple applications that ranges from medicinal field, water and oil treatment, and agriculture purposes. More importantly, it was also nominated as the model material to conduct fracture studies on hydrogel. In this report, dynamic fracture was the mode of fracture selected for the study. While previous studies may have conducted various analysis on dynamic fracture, they have yet to base the research on a material of such significance. Thus, this project would focus on investigating the dynamic fracture properties of PAAm hydrogel and exploring, the relationship between the crack tip velocity and the different pre-stretched conditions. In addition, a proposed crack tip velocity tracking algorithm, using MATLAB image processing toolbox, will be developed to facilitate the project analysis. PAAm hydrogel will undergo tensile loading under dynamic fracture conditions for three sets of pre-stretch configurations. As mentioned, the proposed algorithm will be used to analyse the video recordings of each experimental sets. The algorithm adopted an image processing workflow that comprises of four main stages namely (i) image acquisition (ii) image pre-processing (iii) crack detection, (iv) algorithm calculation. Upon analysing the results with the algorithm, an apparent proportional relationship between the average crack tip velocity and pre-stretched configuration was obtained. Various other key observations were also produced. These pioneer dynamic fracture insights of PAAm hydrogel would provide diverse research opportunities for future developments of its applications.