Development of universal testing machine with digital image correlation system for soft and biomaterials
Project from MECH4429 Integrated Capstone Experience
Project supervisor: Dr. Ko M.W.L. (Department of Mechanical Engineering)
Project leader: Dai Shui Hong Siddhartha, Mechanical Engineering
Team member(s): W.Y.Leung, Mechanical Engineering; C.Y.Leung, Mechanical Engineering; T.K.Pan, Mechanical Engineering; Y.W. Zheng, Engineering Science
The title of the project is “Development of Universal Testing machine with Digital Image Correlation system for soft/biomaterials”
Research on the development of new types of biomaterials has become one of the major focus in the engineering field in recent years. The biomaterial is integrated with medical engineering so it can be engineered to interact with the biological system in the human body for the different medical purpose. In order to opt for the optimal biomaterial for a certain medical purpose, several testing related to the measurement of displacement and strain should be performed on the biomaterial. This project aims to develop an Universal Testing Machine (UTM) with Digital Image Correlation method (DIC) to provide a full field true strain measurement and reduces the disturbance on the local mechanical response of the the local mechanical response of the testing material, providing a better, more precise and immediate strain/displacement analysis of the experiment than using the extensometer.
First, students study the theory of material testing and DIC technology. Second, students design and build up a single column UTM for the material tensile test together with the program coding for the control and sensor system.
After that, the students integrate the UTM and DIC system together, including the sample preparation and testing procedure. Also, the student connects the machine with the camera to provide data and image for DIC system analyze.
Finally, students are successful to measure the field stress-strain distribution and proof the DIC method can improve the UTM measurement performance.
This project consists of two major parts including the development of an universal testing machine (UTM) and the digital image correlation (DIC) system.
From the development of UTM, students acquire different experience from machine design, SolidWorks modelling and fabrication of key components. One of the vital outcomes is learning cross-discipline knowledge. Students need to develop their own control system. They need to integrate the knowledge not only from the mechanical discipline but also from computer science and electronics engineering. For example, control programme coding and circuit board design.
For the DIC system, students also gain different exposure in terms of MATLAB application and analysis. Students make use of MATLAB for image processing, DIC analysis and post DIC analysis. Students need to analyse the data acquired and formulate into meaningful results for calculation.
Students can earn these precious experience other than mechanical engineering lesson. They can also be self-motivated to equip themselves in terms of cross-discipline learning which equips them to be professional engineers in the future.
The project demonstrated how the students could apply their fundamental knowledge obtained during the first three years as an engineering student in a hands-on project. Students can rarely delve into a specific field of study and work on a hands-on project that they are interested in, most of the engineering courses would be theoretical-based. Therefore, this project acts as a balance between the practical and the theoretical element in the curriculum.
The project requires each student to apply their engineering sense and knowledge in different fields, such as Solid Mechanics, Stress and Strain analysis, Product Design and Manufacture, etc. Understanding every basic mechanical theory will be the basis of the capstone project, allowing students to realise the significance of each engineering courses that they’ve enrolled in the previous years.
More importantly, the project provides a good example to the engineering students on how to manage a project or even a start-up business in their future career, from making drafts, purchasing different key components to budget control and work distribution. The final year capstone project is not only a milestone in the engineering students’ university life, it’s also a valuable opportunity to let the students to better equip themselves before going into different industries.
The project requires connect different independent equipment, method and system together. Students need to have a good understanding to each part of the project and develop a new method and system. That’s mean students pick up different skillset such as programming, control and digital image analyze in the short period and find the way to complete the testing system.
The project has been completed with satisfying result among all the groups. It is rare and so difficult that a machine development project can be finished with in a tight schedule. However, showing what they have learnt in their tertiary education is also an important criterion to a good project. From my observation, the team can apply their engineering sense to the project as well as the theories they learnt in lessons.