Simulation of heat flow through composite with defects

• Main Author: Mohammad Shahril Bin Bakar.
• Other Authors: Ng Yin Kwee
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mathematics and analysis::Simulations
• Online Access: http://hdl.handle.net/10356/55205
• Institution: Nanyang Technological University

C040: Simulation of Heat Flow through Composite with Defects is a project dedicated to study the effects of heat transfer characteristics on carbon fibre reinforced composites used in the aircraft industry. This is done for the purpose of defect detection via non-destructive means. The scope of this project involves the following steps: 1. Extracting experimental and simulated data from various research resources and comparing them to the simulated results done by the author. This is done to ensure the competency of the author. 2. Creating a simulation model for the purpose of a combined pulsed thermography & pulsed shearography study together with the analysis on the feasibility of such combination of non-destructive evaluation techniques. The defect depth and size are varied and the results relating to thermography and shearography are analyzed and discussed. A comparison is made between the two methods with the application of a single thermal load. It was found that the temperature difference on the surface of the sound area and the defect is related to the depth of defect beneath the surface up to the midpoint of the specimen thickness. The time difference between the maximum temperature of the sound area and defect was found to be related to the diameter of the defect. Both thermography and shearography has its own advantages and has been applied individually with success in the aviation industry. Pulsed thermography was found to be effective in determining the depth of the subsurface defect while it lacks the resolution to determine the shape of the defect when compared to pulsed shearography. On the other hand, pulsed shearography was capable of detecting the shape of deep subsurface defects and was able to provide a better image contrast seconds after the heat pulse was applied. This is due to the remaining thermal stress that was left behind.