0000000000018197
AUTHOR
Liviu Rosca
Study regarding the influence of material type on economic objectives in MEx fabrication
Material Extrusion has been used extensively as an additive manufacturing technology for a variety of applications like visual models, functional prototypes, tooling components, patterns for castings, and final parts. The current research paper proposes a study on the material type influence on economic objectives in material extrusion fabrication of complex assemblies. Three economic objectives have been analysed, namely, estimated fabrication time, material usage and material cost, whilst two commercial additive manufacturing machines have been considered for the simulation. Cura and ZSuite slicing software were used for the generation of Gcode and project files. Five filaments were selec…
Numerical-Experimental Study Regarding the Single Point Incremental Forming Process
The present paper proposes a numerical-experimental comparative study on the single point incremental forming process. A DC04 steel sheet with a thickness of 0.6 mm was used for both the numerical simulation using the finite element method and the experimental research. The type of trajectory used was a spiral trajectory and the finished part obtained was a truncated cone-shaped part. The analysis program used for simulation was Ls-Dyna. The simulations were performed in several variants: with a fixed mesh and with an adaptive mesh, using two different element formulations: 25 (Belytschko-Tsay formulation with thickness stretch) and -16 (fully integrated shell element modified for higher ac…
The integration of information technologies in the knowledge based organizations
Relations between the users' expertise, complexity of tasks to be solved by knowledge-based organizations and mission of smart information systems, is a multi-dimensional structure that should provide the necessary conceptual framework of sustainable integrated smart development. The users of smart information systems face a variety of problems, such as: system access, data recovery, identifying and retrieving a specific document and its contents, and difficulties associated with understanding and interpreting of the used system on stages and methods following to be used, respectively problems on understanding the meaning of information provided. Using smart information systems and smart da…
Comparison of problem solving tools in lean organizations
As global market competition is getting fiercer, and companies are looking at ways to stay on top, more and more organizations are looking at Lean Manufacturing and lean tools to support them in achieving their goals. Especially within the automotive industry, lean practices are very well received. The speed at which the automotive industry is evolving, especially but not only, in countries like Romania, leads to the need to carefully analyze lean manufacturing concepts, examine them against local production conditions, and to develop and standardize them. One of the most important things to take into consideration here is the application of an adequate problem solving technique to avoid wa…
Comparative Study for Springback Prediction on Single Point Incremental Forming Process
The present paper proposes a comparative study in order to determine the springback in single point incremental forming process. Using the Ls-Dyna software the process was simulated for one piece in frustum of pyramid shape. In the end of the explicit dynamic analysis, it was run, using the same software, an implicit analysis to determine the springback. For this comparison study we selected four different shell formulations. The results obtained in this simulation were compared with those obtained experimentally for the same part. The experimental research was conducted on a robot and, on the opposite side of the machined surface, an Aramis measuring optical system was placed to allow the …
Inverse Analysis Used to Determine Plastic Flow and Tribological Characteristics for Deep-drawing Sheet
Abstract The present paper aims to develop a simple method based on inverse analysis that allows us to determine the laws of plastic flow coefficients and the friction coefficient between the material and punch. Selecting from different types of tests, we have chosen the Hecker test, because this test requires a single form of punch, the hemispherical one. In this test, the friction between the punch and the blank-sheet is caused by the blank-sheet strains and not by the movement it makes (as in deep drawing case). Besides the friction coefficient, other parameters like hardening and strength coefficients (n and k), influence the distribution of stresses and strains in the material. Using t…