Material flow

About: Material flow is a research topic. Over the lifetime, 3050 publications have been published within this topic receiving 36844 citations. The topic is also known as: material stream.

Using metaheuristic and fuzzy system for the optimization of material pull in a push-pull flow logistics network

Abstract: Alternative material flow strategies in logistics networks have crucial influences on the overall performance of the networks. Material flows can follow push, pull, or hybrid systems. To get the advantages of both push and pull flows in networks, the decoupling-point strategy is used as coordination mean. At this point, material pull has to get optimized concerning customer orders against pushed replenishment-rates. To compensate the ambiguity and uncertainty of both dynamic flows, fuzzy set theory can practically be applied. This paper has conceptual and mathematical parts to explain the performance of the push-pull flow strategy in a supply network and to give a novel solution for optimizing the pull side employing Conwip system. Alternative numbers of pallets and their lot-sizes circulating in the assembly system are getting optimized in accordance with a multi-objective problem; employing a hybrid approach out of meta-heuristics (genetic algorithm and simulated annealing) and fuzzy system. Two main fuzzy sets as triangular and trapezoidal are applied in this technique for estimating ill-defined waiting times. The configured technique leads to smoother flows between push and pull sides in complex networks. A discrete-event simulation model is developed to analyze this thesis in an exemplary logistics network with dynamics.

Numerical simulation of friction stir welding

Abstract: Friction stir welding is a solid-state welding technique that utilizes thermo-mechanical influence of the rotating welding tool on parent material resulting with monolith joint-weld. On the contact of welding tool and parent material, significant stirring and deformation of parent material appears, and during this process mechanical energy is partially transformed into heat. The paper describes the software for the numerical simulation of friction stir welding developed at Mechanical Engineering Faculty, University of Nis. Numerical solution for estimation of welding plates temperature is estimated using finite difference method-explicit scheme with adaptive grid, considering influence of temperature on material's conductivity, contact conditions between welding tool and parent material, material flow around welding tool etc. The calculated results are in good agreement with the experimental results.

Material flow analysis in the incremetal forging technology

Abstract: An incremental forging process created on the basis of the modified orbital forging press is investigated in the paper. Development of the finite element model, which simulates metal flow in this process, is the main objective of the work. This model is used in research on possibility of modification of classical orbital forging technology to obtain more efficient process. Due to the novelty of the developed process, the investigation on path of material flow during deformation is of particular interest in this work. A numerical simulation involve subsequent pressing of a set of anvils into the material. Direction of material flow and strain path change, due to incremental character of deformation, are analysed. The results showing flow of metal under the anvils are presented and discussed in the paper. Zone affected by the incremental character of deformation is identified in narrow region in-between subsequent dies. Examples of results of numerical simulations of modified orbital forging press are presented in the paper, as well.