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.

Complex material flow problems: a multi-scale model hierarchy and particle methods

Abstract: Material flow simulation is in increasing need of multi-scale models On the one hand, macroscopic flow models are used for large-scale simulations with a large number of parts On the other hand, microscopic models are needed to describe the details of the production process In this paper, we present a hierarchy of models for material flow problems ranging from detailed microscopic, discrete element method type, models to macroscopic models using scalar conservation laws with non-local interaction terms Numerical simulations are presented at all levels of the hierarchy, and the results are compared to each other for several test cases

Method and apparatus for determining the material flow rate of conveying mechanisms

Abstract: A method and apparatus for determining the material flow rate of bulk material, transported by belt conveyers or the like, by continuously determining the contour of the free surface of the bulk material, at right angles to the direction of transport, via continuous non-contact distant measurement using transmitter-receiver mechanisms coupled with a computer, and by computing the cross section of the bulk material. A precise and reliable measurement of the height of bulk material on the conveyer belt is achieved by using, as the transmitter-receiver mechanisms, respective laser distance-measuring devices which emit and receive a reflecting laser beam. These devices preferably operate pursuant to the pulse transit time measuring principle. The laser distance-measuring devices are accommodated in a housing.

Compression molding simulation of chopped fiber reinforced polymeric composites in plate‐rib type geometry

Abstract: A study on anisotropic material flow of polymeric composites in compression molding was conducted. Flow resistance and material anisotropy were measured by compression and tension tests to quantify the inhomogeneity of chopped fiber reinforced polymeric composites. The material was assumed to obey Hill's anisotropic yield criterion with its associated flow rule. An anisotropic finite element formulation was developed to simulate the material flow under various conditions. This two-dimensional model was applied to plane strain compression in a mold with plate-rib type geometry to substantiate the effect of fiber induced anisotropy. The predictions were compared with experimental results.

Control of the material flow in sheet-bulk metal forming using modifications of the tool surface

Abstract: Sheet-bulk metal forming (SBMF) processes are characterized by a successive and/or simultaneous occurrence of different load conditions such as the stress and strain states. These conditions influence the material flow and often lead to a reduced geometrical accuracy of the produced components. To improve the product quality, a control of the material flow is required. One suitable approach, the local adaption of tribological conditions by means of surface modifications of tool or workpiece, so-called tailored surfaces. To control the material flow and thus to improve the component accuracy, methods to reduce and to increase friction are needed. The aim of this study is to determine requirements for necessary adaptions of the friction, the identification of tribological mechanisms for different types of tool-sided tailored surfaces as well as the verification of the effectiveness of these surface modifications to improve the results of a specific SBMF process. The numerical analysis of a combined deep drawing and upsetting process revealed that this process is characterized by two areas of varying tribological load conditions. Using a numerical analysis, the friction factor gradient between these two areas was identified as a main influencing factor on the material flow. Based on this finding, Chromium-based hard coatings for the reduction of the friction and high-feed milled surfaces for an increase of the friction were investigated regarding their frictional behaviour. The results of the ring-compression tests revealed that the carbon content and the post treatment of coated tool surfaces are relevant to reduce the friction. The increased profile depth of the milled surfaces was identified as the main influencing factor on the tribological behaviour of this kind of tailored surfaces. The effectiveness of both types of tailored surfaces was verified for the combined deep drawing and upsetting process.