Extrusion Operations Research Articles

Streamlining BIM models for GIS integration: an advanced approach to building envelope extraction

ABSTRACT Building Information Modelling (BIM) models are crucial for urban building modeling in three-dimensional (3D) Geographic Information Systems (GIS); however, their intricate nature requires lightweight design for seamless GIS integration. Envelope extraction is a primary method for achieving lightweight BIM; nevertheless, it encounters challenges related to robustness and simplification. To tackle this issue, this study proposes a more effective envelope extraction method. Initially, BIM elements are categorized into three types based on their semantics: space-occupying, portal, and other facility elements. Subsequently, for space-occupying elements, a 3D alpha wrapping algorithm is employed to obtain a tightly enveloped triangular mesh and then simplified into a lightweight polygonal mesh. Finally, portal elements are replaced with simplified proxies and embedded into a polygonal mesh through extrusion operations to refine the model. The refined model is combined with other facility elements to achieve the final simplification result. Experiments were conducted using publicly available datasets and manually created BIM models of various types and complexities. The experimental results demonstrate that our method significantly reduces the data volume of BIM models while maintaining their accuracy. Furthermore, this approach does not necessitate strict geometric requirements for BIM building elements and allows for gaps between them, thereby exhibiting higher robustness.

Fabrication of graphene-rapped melamine sponge and its photothermal adsorption on viscous oil spill

Graphene oxide melamine sponges (GOMSs) were prepared by impregnating melamine sponge (MS) with graphene oxide (GO) dispersion. Thereafter, reduced graphene oxide melamine sponges (HGOMSs) were obtained by one-step heat treatment of GOMSs, and the effects of heat treatment and GO load on sponge structure, hydrophobicity/ lipophilicity, photothermal properties, mechanical properties and light-aided adsorption performances were evaluated. The results show that heat treatment under 400 °C is an optimum choice. A small amount of graphene could effectively wrap on the melamine sponge skeleton and closely combined with the sponge. This effectively wrapped structure can not only improve the photothermal and mechanical properties of the sponge, but also retain the rich pore structure of the sponge to provide sufficient space for oil adsorption. HGOMS prepared under 400 °C with 1 mg·ml−1 of GO concentration shows an average light absorption rate of 84.4% in the full solar spectral range. Under 1 sun illumination in air, the surface can quickly rise to 99.4 °C, and the bottom surface is 72.8 °C, showing excellent photothermal conversion performance. The saturated adsorption capacity on heavy oil reached 103.2 g·g−1 under 1 sun illumination. The material was reused through mechanical extrusion method. After 10 times of adsorption- extrusion operations, its saturated adsorption capacity still retained more than 80% of the first time. These characteristics make HGOMS an energy efficient and reusable adsorbent for oil spill.

Liquid to Fused Deposition Modeling (L-FDM)—A Revolution in Application Chemicals to 3D Printing Technology—Mechanical and Functional Properties

A novel L-FDM technique that builds upon the fundamentals of the FDM additive manufacturing process has been developed. It includes a mechanism that directly incorporates a chemical substance and alters polymer fibers throughout the fine process. This method eliminates the need for additional extrusion operations and compounding equipment to introduce chemical additives and solvents. This advancement opens up new opportunities for printers to be used in chemical labs to test new or known chemical substances. The paper outlines the technological assumptions, potential applications, and practical examples of direct filament modification using the L-FDM technique. The modifications made to the mechanical properties of the printed objects were confirmed through thermal analysis techniques (DSC), water contact angle measurements, electron microscopy (SEM-EDS), and mechanical analysis.

Al/Al-B4C Dairesel Hibrit Kompozitlerin Mekanik Özelliklerinin İncelenmesi

Hybrid composites are material types obtained by combining two different composite structures. In this study, the mechanical properties of the circular hybrid composite materials which was produced in the form of rod with aluminum sheath and metal matrix composite core (Al-Ceramic mixture) were investigated under compression and bending loads. Although some mechanical properties of metal matrix composites (MMC) are improved with ceramic reinforcement, some of their properties as deformation ability is reduced. It was aimed to increase them by forming aluminum sheath on the outside of these materials. Al7075 aluminum alloy was used as sheath material while Al2124 alloy and B4C were used as core material. Extrusion process was used to produce the composite rods. The extrusion billets were produced with PIT (powder in tube) method. In this method, Al2124-B4C powder mixture was compressed in Al7075 tubes. Al2124-B4C powder mixture was prepared volumetrically at three different ratios (% 5, % 10 and % 15). The extrusion operation was realized at constant temperature (500 °C) and constant extrusion rate (R=14) and the composite rods produced in 8 mm diameter. The composite bars produced with and without sheaths were subjected to compression and three-point bending tests. According to the test results, with increasing of the B4C ratio in MMC bars, the deformation rate decreased rapidly. In the composites produced as hybrid, it was seen that the deformation ability increased and this showed that the aluminum sheath provided the desired improvement.

Thermal and mass aspects of Maxwell fluid flows over a moving inclined surface via generalized Fourier’s and Fick’s laws

The fascination with the presentation of features of non-Newtonian fluid is due to practical applications in the food processing, chemical, biomedical, and allied processing industries. The modes class of non-Newtoinian rate-type fluids is Maxwell fluid which has engineering and industrial applications. These applications include the movement of organic liquids, food dispensing, the application of paints, glass fiber, electronic chips, extrusion operations, and papermaking. Due to above said significance the present study is focused on the boundary layer flow of Maxwell fluid with Generalized Fourier's and Ficks’ Laws along the moving plate with constant velocity is organized. The mathematical description of the suggested mechanism is given in terms of partial differential equations, which are then converted to ordinary differential equations using the proper similarity transformation and solved via a bvp4c solver. The solutions for velocity, temperature, and concentration profiles along with their gradients against the pertinent parameters are obtained and displayed in graphs and tables. It is deduced from the presented results that the velocity field is increasing functions concentration relaxation parameter but decreasing the function of Deborah number, angle of inclination, and thermal relaxation parameter. The temperature and concentration fields show an increasing trend against Deborah's number, and angle of inclination. These show the decreasing trend against the concentration relaxation parameter. A comparison of the present results with previously published results is presented for the validation of current solutions.

SHAPING OPERATIONS OF EXTRUSION AND ROTATION OF SOLID-STATE MODELING OF GEOMETRIC OBJECTS IN THE POINT CALCULUS

The shaping operations of extrusion and rotation within the framework of point calculus are implemented. The principles of parametrization of bodies in point calculus are described. When considering the extrusion operation, the cases of performing this operation at a right angle and with a variable inclination angle of the generatrix are taken into account. When implementing the rotation operation, the method of polar parameterization of the sketch plane is considered. Due to the use of point calculus, the proposed approach makes it possible to obtain body models in the form of a three-parameter set of points in the three dimensional space, the density of which depends on the parameters of the three dimensional model set by the designer. The analysis of existing systems of solid modeling and their capabilities in the direction of creating solid models of bodies is carried out. It showed that almost all of them provide the user with models presented as surfaces of body shells and are not filled with points. None of the existing CAD makes it possible to model a body in the form of a three parameter set of points. And when trying to use the proposed modeling apparatus within existing computeraided design systems (for example, outputting a model in the form of a set of points through the API of these systems), we risk getting a body model that is simply impossible to work with due to the excessive consumption of PC resources used for modeling (for example, even a model of a simple body with a high density of points can lead to a “freeze” of the system even on a computer with high computing power). In addition, the evaluation of the effectiveness of the mathematical apparatus embedded in the modeling systems cannot be effectively carried out since the mathematical basis of these CAD systems is a trade secret. In this case comparison is necessary, since the proposed three dimensional models consist of the same type of equations along all coordinate axes, which, if used correctly in CAD, can lead to significant savings in computing power due to parallelization of the data processing across different computational threads.

EVALUATION OF DEFORMABILITY OF MATERIAL OF PREPARATIONS IN DIRECT AND REVERSE EXTRACTION BY ROLLING STAMPING METHOD

The article presents the results of development and research of various technological schemes of the process of stamping by rolling cylindrical and conical rolls to obtain complex profile workpieces. It is shown that the achievement of significant dimensions of the various elements of the workpiece is possible by providing a directed flow of metal by changing the relative position of the roll and the workpiece. The most effective rolling operations are landing, settling, unloading, reverse and direct extrusion. The paper focuses on the analysis of operations of reverse and direct extrusion to obtain complex profile blanks with developed, including thin-walled elements. Since the technological capabilities depend on the deformability of the material, the analysis of the stress-strain state of the workpieces was performed using the method of grids, hardness measurement and microstructural analysis. The main result of the analysis was the construction of ways to deform the particles of the workpiece material in the coordinates "deformation intensity - stress index". Zones of blanks that are deformed in the conditions of "rigid" stress state are established, therefore for these zones the deformability of metals was assessed using the criteria of phenomenological theory. In addition, the assessment of deformability was also performed for areas with the maximum degree of deformation of the material. The manufacture of thin-walled elements of the workpiece, using the operation of reverse extrusion, is accompanied by the appearance of significant contact stresses. To prevent the roll from being pushed out of the workpiece and forming elements with a constant thickness, support rollers should be provided. In the case of direct extrusion, the increase in contact stresses requires the application of additional measures to increase the strength of the tool.

Theoretical studies of reverse extrusion of steel pipe by conical punch

The reverse extrusion operation of steel pipe by a conical punch for manufacture of semi-finished parts of the "body" type with a difference in wall thickness along the height is considered. Computer simulation and mathematical modelling of this process is carried out. Rational modes of deformation during reverse extrusion of pipe blanks are established.

CAD-integrated topology optimization method with dynamic extrusion feature evolution for multi-axis machining

This paper proposes a subtractive geometry projection topology optimization approach to simulate the multi-axis machining process and remove material from the initial design domain. Each geometric primitive is described by a plane extrusion operation based on a 2D closed cubic spline curve controlled by boundary points. The reference plane for the 3D extrusion operation can freely rotate and translate in the design space for optimization. The primitive is then projected onto the mesh based on the Heaviside function to modify the density distribution. The cutting primitives are combined using the p-norm aggregation function to produce the final subtractive design. The method of moving asymptotes method is implemented to optimize each geometry primitive based on analytical gradients. One of the major advantages of the proposed method is its ability to readily integrate the modeling history into the optimization process, paving the way to construct commercial CAD compatible designs.

Innovative Technology for Stamping a Small-Sized Sleeve Blank

The work is devoted to the development of an innovative technology of stamping from low-carbon steel for small-size liner blanks. The sequence of punching transitions includes a cold back extrusion operation, two cold drawing operations with thinning, and a cold crimping operation. Simulation with the use of the finite element method established the forces and specific forces during operations, the thermal effect during shaping, the shape and size of semi-finished products with distributions of the intensity of deformations. An elastoplastic metal model was used, which made it possible to reveal the deformation forces, tool extraction from deformed semifinished products and the effort to remove semifinished products from the dies. A hollow semi-finished product is obtained by reverse extrusion. The possibility of carrying out the first drawing operation with thinning through two sequentially located dies with the formation of a hole in the bottom part is shown. After this operation, annealing of the semi-finished product is required to restore plasticity. In the second operation, thinning stretching. The shape and dimensions of the wall of the semi-finished product after the second drawing, the distribution of the intensity of deformations in it are determined from the condition of reaching the final dimensions and mechanical properties of the sleeve blank at the last crimping operation. For this, the deformations obtained as a result of the second drawing are taken into account when modeling the crimp. For each transition of stamping, a construction of stamping equipment has been developed. The proposed technology for stamping a sleeve blank can be implemented on a universal pressing equipment, has a high productivity due to a reduction in the number of transitions and minimizes mechanical processing.

Extracting datums to reconstruct CSG models from 2D engineering sketches of polyhedral shapes

Our goal is to automatically generate CAD 3D models from 2D sketches as part of a design chain where models should be procedural, containing features arranged in a model tree and linked to suitable datums. Current procedural models capture much about the design intent and are easy to edit, but must be created from scratch during the detailed design state—given conceptual sketches as used by designers in the early part of the design process, current sketch-based modeling approaches only output explicit models. Thus, we describe an approach to extract high-level information directly from 2D engineering wireframe sketches and use it to complete a CSG feature tree, which serves as a model tree for a procedural 3D CAD model.Our method extracts procedural model information directly from 2D sketches in the form of a set of features, plus a set of datums and relationships between these features. We detect and analyze features of 2D sketches in isolation, and define the CSG feature tree by the parent–child relationships between features, and combine this information to obtain a complete and consistent CSG feature tree that can be transferred to a 3D modeler, which reconstructs the model. This paper focuses on how to extract the feature datums and the extrusion operation from an input 2D sketch.

Simulation Upper Bound Theorem to Prediction Extrusion Load

A metal extrusion was process that extrusion puncture perforate surface of material to throw and flow across outlet of die. This operation was a complex process in extrusion while penetration occurred at same time. This process can be seen in many production operations, like in forming of making portion of metal strip, and forming of extruded portion in a complex fineblanking with extrusion operation. Also exhibit the operation properties and give the method of numerical solution. So increasing load to 610KN with increased friction factor to 0.7 and increased with increasing the reduction ratio and stroke of operation. For the results and mesh distortion, with allocations of strains may be predicted. Analyzing results was submitted of metal extruded may be classified into two zones for the different lineaments deformation. moreover, energy in the zones of deformation may be classified into two parts for their different lineaments of internal zone and contact zone with the die . Fracture location has been found from simulations. Keyword Load, Extrusion, upper bound, numerical solution

Stamping a medium – sized cartridge blank from low – carbon steel

The work is devoted to obtaining a medium – sized cartridge blank from low-carbon steel. The sequence of punching transitions includes a hot back- extrusion operation, two cold draw – thinning operations, and a cold crimp operation. Modeling using the finite element method established: efforts and specific forces during operations, thermal effect during shaping, shape and size of semi – finished products with distributions of strain intensity. An elastoplastic metal model was used, which made it possible to reveal the forces of extracting the tool from deformed semifinished products and the forces of removing semifinished products from the matrix. A hollow semifinished product with the required dimensions of a protrusion on the bottom part from the side of the cavity and a protrusion on the end for forming a flange is obtained by reverse extrusion. The possibility of carrying out the first drawing operation with thinning through three sequentially located matrixes is shown. After this operation, annealing of the semi-finished product is required to restore plasticity. In the second operation of drawing with thinning and additional stamping of the bottom part, the final dimensions of this part from the side of the cavity and the shaping of the flange on the lateral surface of the semi-finished product are provided with the creation of a macrostructure to ensure the required operational properties. The shape and dimensions of the wall of the semi-finished product after the second drawing, the distribution of the intensity of deformations in it are determined from the condition of reaching the final dimensions and mechanical properties of the cartridge blank at the last crimping operation. For this, the deformations obtained as a result of the second drawing are taken into account when modeling the crimp. The proposed technology for stamping a blank of a sleeve can be implemented on a universal press – forging equipment, has a high productivity and minimizes mechanical processing.

Experimental study of the simultaneous effects of severe plastic deformation and secondary radial strain on copper

Due to the widespread use of copper wires in electrical power transmission, the need for raw materials with a homogeneous structure and high strength while maintaining their conductive properties is of high importance. The present study investigates the production of copper wire with improved mechanical properties and homogeneous microstructure due to its nanometre-sized structure. Therefore, the commercial pure copper specimens were subjected to severe plastic deformation (SPD) by means of equal channel angular pressing (ECAP) during four steps at ambient temperature. Due to the creation of a structure with elongated grains in the ECAP process, the deformed specimens were subjected to the direct extrusion operations; thus, a more homogeneous structure was created in them due to the appearance of a secondary radial strain. The obtained results indicate that by applying the simultaneous effects of SPD and direct extrusion on the microstructure, the mechanical properties such as strength and hardness have improved significantly, while the electrical conductivity of pure copper decreased slightly. The outcome can be used as an alternative to current methods for producing high-strength copper wires with suitable electrical conductivity properties.

A study on melt recycling of bio‐based polypropylene/thermoplastic starch compound

AbstractThe compulsion to use bioplastics has increased significantly today. One of the important aspects of plastics is their recyclability. Therefore, the important question of this research is that although bio‐based compounds containing starch are sensitive to thermal‐mechanical recycling processes, are such products thermally recyclable? To answer the question, polypropylene (PP)/thermoplastic starch (TPS) compound granules were extruded up to five times, and in the other part, single‐extruded granules were blended at different ratios with virgin granules by extrusion. In order to characterize these samples, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, rotational disc rheometry, tensile properties, and appearance evaluation were used. The results showed that it is possible to recycle PP/TPS granules up to four times repetition of the extrusion operation and the fifth repetition also showed slight changes. There was also a blend of single‐extruded granules with virgin material up to a 50:50% composition without significant variation.

Tectonic history related to the southern section of the Kalinjala Shear Zone, Eyre Peninsula, South Australia: And correlations with Terre Adélie Craton, Antarctica

The southern edge of the Eyre Peninsula, experienced a separation from proto-Antarctica in the Cretaceous and has been projected to extend into Terre Adélie Craton, Antarctica. The Archaean and Palaeoproterozoic rocks of the southern Eyre Peninsula, have been modified by the Kimban Orogeny (~1730–1690 Ma) with the development of the regionally extensive Kalinjala Shear Zone, which has been correlated with the Mertz Shear Zone in Antarctica. In this contribution, new structural observations associated with the granulite facies Kalinjala Shear Zone, together with other shear zones, all showing similar kinematics of dextral top-to-the-north transport will be described. The Kimban Orogeny overprints and reworks a major lithospheric boundary between the Gawler Craton and a sequence of preceding events related to the ~ 1850 Ma Cornian Orogeny. Shear zones were initiated during the early stage of the Kimban Orogeny (KD1) in a dextral simple-shear regime, transitioning into a pure-shear (KD2) dominated regime. With shortenings of > 90% in the Kalinjala Shear Zone localized into regions containing pre-existing Tourneford Metdolerite Dykes emplaced at ~ 1810 Ma into the granites of the Donington Suite (1850–1843 Ma) and a basement of 2000–1859 Ma paragneisses. Geometrical relationships reveal the operation of oblique extrusion during the Kimban Orogeny, where a coaxial component acted sub-horizontal and orthogonal to the trend of the Kalinjala Shear Zone. Regions of low-strain and a ‘pinched-in’ and inverted sequence of Mesoproterozoic metasedimentary cover, the Hutchison Supergroup, are bounded by major km-scale shear zones with steep west-dipping tectonic contacts. Post-Kimban subvertical east–west-trending joints and faults record a rifting event which can be related to a Gondwana breakup. With post-rift Neogene fault activity recording additional tectonic episodes where pre-existing basement structures exert significant control on their orientation and distribution. Palaeogeographical reconstructions between the Eyre Peninsula and the Terre Adélie Craton, based on matching basement geology and structural style, are compared and reconciled with this new information.

Study of dependence of hardness of steel cylindrical parts on technological parameters

On the basis of the conducted experiments with the use of pressing and thermal equipment, a mathematical model of the value of the wall hardness of the semi-hot extrusion machine as a key process in the manufacturing technology of steel cylindrical hollow parts manufactured for the mechanical engineering and mining industries was obtained using experimental planning methods. It is noted that the technological process of manufacturing steel cylindrical hollow parts with a key operation of double-sided semi-hot extrusion with distribution is a promising process that allows to ensure high plasticity and strength of the semi-finished product material and obtain the required mechanical properties of the metal. The developed mathematical model made it possible to solve the actual problem of choosing the optimal modes and parameters of the semi-hot extrusion process (processing temperature, degree of deformation, temperature of the cooling medium, geometry of the working tool) and to provide the ability to control the formed properties of the product together with the finishing operations of drawing. Graphical dependences of the wall hardness of the semifinished product on the processing temperature at different values of the radius of the working part of the punch, the degree of deformation and the temperature of the cooling medium are constructed and analyzed. Analysis of the obtained graphs allowed us to identify the parameters that have the greatest impact on the wall hardness of the semi-finished product.

Mechanical properties comparison between new and recycled polyethylene terephthalate glycol obtained from fused deposition modelling waste

The recycling of materials and the efficient use of resources are nowadays fundamental in a circular economy perspective. This concept also applies to additive manufacturing (AM) where waste can be reused to produce new material. Using mostly thermoplastic polymers, fused deposition modeling (FDM) is an AM technique that allows to melt waste materials and, successively, using a suitable extruder, obtain new filament. In the process, polymers are subject to multiple re-melting and polymer orientations by extrusion operations. The aim of this work is to evaluate the influence of the recycling process over polyethylene terephthalate glycol-modified (PETG) mechanical properties by tensile testing of samples produced using pure and recycled material. Furthermore, filament itself has been tested to evaluate recycle process influence before FDM printing.

Contribution to process digitisation of cold forging processes using additive manufactured tools

Cold forging tools become increasingly complex and require enhanced functionality, especially in the context of digitisation. Conventional subtractive manufacturing processes often reach their limits when the geometric complexity of the workpiece increases, hence additive manufacturing processes have become increasingly important in the last decades. Additive manufacturing processes have already been used in many fields of manufacturing technology to produce tool components with promising results, but the potentials of additive manufacturing processes have not yet been applied to cold forging tools. Therefore, the Institute for Metal Forming Technology (IFU) of the University of Stuttgart has developed an additive manufactured cold extrusion tool with integrated functional features. As functional features in the additive manufactured extrusion tool, a close contour glass fiber sensor for temperature measurement, a cooling system and a lubrication system for the controlled injection of minimal lubricant amounts during the forming process were integrated. Due to the integrated functional features, structural degradation appears in the tool, therefore the structural-mechanical tool properties were analyzed numerically with the FE-Software DEFORM 3D™ in this report as well. Furthermore, the additive manufactured cold extrusion tool was experimentally evaluated in sequentially executed extrusion operations. Thereby the integrated functional features were used and gathered data were recorded. As a result of the experimental forming tests, near-contour temperature measurements in the extrusion tool with and without the use of the integrated cooling system as well as the modification of the maximum punch forces by an inline lubricant application were obtained. In addition, the experimentally determined temperature fields in the extrusion die are validated with numerically calculated results.

Advances and Trends in Forming Curved Extrusion Profiles.

Curved profiles/sections have been widely used for manufacturing lightweight structures with high stiffness and strength due to aerodynamics, structural properties, and design reasons. Structural components fabricated using curved aluminum profiles satisfy the increasing demands for products used in many high-technology industries such as aerospace, shipbuilding, high-speed rail train, and automobile, which possess the characteristics of lightweight, high strength/stiffness relative to weight, superior aerodynamics performance, and aesthetics. In this paper, the advances and trends in forming techniques of curved extrusion profiles of metal alloys have been reviewed. The curved profile forming techniques are classified into three major categories: conventional cold bending technique, stress/moment superposed cold bending technique, and extrusion-bending integrated forming technique. Processes for innovative development in the field of forming curved profiles are identified; the extrusion-bending integrated technique which can directly form the billets into curved profiles by one single extrusion operation possesses the full potential for further innovation. Due to the nature of the research to date, much of the work referred to relates to hollow circular and rectangular tube cross-sections.