Effect of External Perimeter on Flexural Strength of FDM Build Parts

Abstract

Current manufacturing trend adopts newer technology that can reduce both the design and manufacturing lead time in order to face the challenging demands of the customer in an effective manner. In this regard, rapid prototyping technology, among all newly developed technologies, is reliable one because it is capable of manufacturing accurate and durable parts with 3D complex geometry within a stipulated time with less material waste. In this research work, effect of six relevant controllable input parameters (contour number or external perimeter, layer thickness, raster width, part orientation, air gap and raster angle) on flexural strength of the fused deposition modelling (FDM) build parts is analysed. Experimentation has been carried out using face-centred central composite design to reduce the number of experimentation. Contour number appears to be more influencing parameter because it helps to move the stress concentration zone from outer edge to the centre avoiding premature failure of the specimen. The study develops a statistically valid empirical model relating flexural strength with process parameters to ease prediction of flexural strength by tool engineers. Scanning electron microscope micrographs are used to explain the microstructure behaviour of FDM build parts when subjected to three point bend test. Finally, one nature-inspired metaheuristic approach known as Firefly algorithm is adopted to obtain optimal parameter setting for improving the flexural strength.