The present work investigates, by both mathematical modelling and experiment, the contribution of bonding between the filaments to the strength of the parts manufactured by fused deposition modelling (FDM). A mathematical model for neck growth between cylindrical filaments is derived based on viscous sintering for cylindrical filaments. Theoretical ultimate tensile load is determined from the layer thickness information and predicted average final neck size between filaments. The experimental ultimate tensile load is obtained by conducting a simple tension test with two different build directions. Agreement between theoretical and experimental ultimate tensile load and scanning electron microscope (SEM) photomicrographs of the fracture surface indicate that the strength of the FDM part is primarily due to intra-layer bonding, interlayer bonding and neck growth between filaments. It also indicates that the total time and heat available to the filaments are just sufficient to grow necks but not enough to fully coalesce.
Fused deposition modeling (FDM) has evolved as one of the fastest growing layer manufacturing (LM) technology because of its capability to build even functional plastic parts with geometrical complexity in a reasonable time period. The quality of the production process depends on various process parameters, the most important of them being layer thickness (h), raster angle (θ), orientation (φ), contour width (c) and part raster width (w). In the present study, the influence of these parameters on two process quality parameters, namely, build time and the support material volume are studied on a rotational part modeled on a FDM 200mc machine. A 25 full factorial Design of Experiments (DOE) methodology was employed and the results for build time and support material volume of the 32 experiments were analyzed using Design Expert®. Analysis of variance (ANOVA) was done and based on the ANOVA results the model equation for the two quality parameters in both coded and original factors has been developed. Comments on the results obtained and interaction effects are included at the end of the paper.
This paper investigates the effect of element size and adaptive re-meshing technique in numerical simulation of incremental sheet forming (ISF) process. In ISF a hemispherical headed tool moves along the specified trajectory to deform the sheet in to required shape. This tool path is generally very long and thus increases the computational time. Therefore, in this work adaptive remeshing technique has been used to minimize the computational time without sacrificing the accuracy of the results. For this a varying wall angle conical frustum was simulated using shell elements with different element edge lengths and adaptive mesh. Effects of these mesh parameters on plastic strain, punch force and form accuracy of deformed geometry has been studied. The necessary simulations for this study are performed using explicit finite element code LS-DYNA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.