Non-linear analysis of brittle and ductile plastic beams in bending

• Main Author: Budi, Christopher Otto
• Other Authors: Chai Gin Boay
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/76268
• Institution: Nanyang Technological University

This project aims to investigate and analyze failure modes of Fiber-Metal Laminates (FML) by simulating their behavior using Polycarbonate and Acrylic. The experiments were done on different stacking order and span lengths of the specimens. Observations on the two factors specifically the specimens’ failure modes and performance were also performed. Airliners today hold a big contribution in the aviation industry all over the world compared to other purposes such as military aircraft, general and business aviation. Being the main body component of most airliners is Fiber-Metal Laminates. However, FML itself does not allow for visual analysis on its failure process due to its constituent materials that are not transparent. To get a better analysis on how the failure initiates and propagates in FML, polycarbonate and acrylic were used in place of the respective aluminum and composite material. This is to simulate the behavior of FML and exploit their transparency for a better observation. Tensile and three-point bending tests were conducted on (i) a single layer polycarbonate, (ii) an acrylic, and (iii) the laminates combining the two of them. Laminates tested in this experiment were in two different stacking order of PC-A-PC (PAP) and A-PC-A (APA). Moreover, the laminates were treated with 2 different gluing methods which were analyzed through bending test. In addition, different span lengths of 100, 150, and 200 mm were also tested with the bending test. The results obtained from this experiment includes a comparison between single layer and multilayer specimens based on both tensile and bending tests. Analysis on the effect of using modified flexural stress formula for large bending, different gluing methods, and different span length in bending were also examined. Moreover, the analysis also includes observations on specimens’ failure modes for both tests.