Perpustakaan Digital ITB

Aluminum foam sandwich (AFS) is a novel class of sandwich structures that has promising applications due to their good mechanical properties. However, buckling is the most serious failure of sandwich structures under in-plane and compressive loads. The objectives of this thesis include to theoretically study the buckling behaviors of AFS plates, to conduct numerical analysis to simulate the buckling phenomena, and to develop a digital image correlation (DIC) method for measurements of three-dimensional (3D) and whole-field displacements. Finite element simulations using both linear and nonlinear methods were conducted. Numerical results of buckling loads were in good agreements with analytical predictions. It was shown that AFS offers higher wrinkling resistance than some honeycomb sandwiches and that geometrical imperfection and material plasticity induce negative effects to buckling resistance. A 3D-DIC system was developed based on the principle of computer vision. Images of a deformable specimen are recorded by two digital cameras during its loading process and analyzed by an image processing code for 3D shapes and 3D displacement fields. Accuracy of the system was evaluated by an error analysis and a translation test. This 3D-DIC system is supposed to be applied for sandwich buckling experiments in following stage of the research work, as well as many other experiments.