Search results for "PROCESSES"
showing 10 items of 3831 documents
Geomaterials in green building practices: comparative characterization of commercially available clay-based plasters
2013
Three pre-mixed powdered clay-based (earthen) plasters produced in Europe and specifically designed for wall undercoating were analyzed in this paper. These materials are commercially available and successfully employed in green building practices all over the world. Their compositional and textural characteristics, as well as plastic behaviour were investigated through a multi-analytical approach: X-ray powder diffraction (XRPD), polarized light microscopy (PLM), X-ray fluorescence spectrometry (XRFS), scanning electron microscopy equipped with an energy dispersive spectrometer (SEM-EDS), mercury intrusion porosimetry (MIP), grain-size distribution (GSD) and semi-empirical tests (Atterberg…
Energy Efficiency of Sheet Metal Working Processes: Where do we stand today?/Energieeffizienz in Prozessen der Blechumformung – eine aktuelle Standor…
2014
Due to increasing energy and resource costs at the one hand and upcoming regulations on energy and resource efficiency at the other, a growing interest of machine tool builders to the environmental performance of their machine tools can be observed today. The last decade, academic as well as industrial research groups started to assess the energy demand of discrete part manufacturing processes and indicated a significant potential for improvement [1]. In contrast to conventional machining processes (e.g. milling, turning…), (sheet) metal forming processes are still less well documented in terms of their energy demand [2]. In consequence, potential energy efficiency improvement measures for …
ROUGHNESS CONTROL OF PARTS OBTAINED THROUGH INCREMENTAL SHEET FORMING
2007
Abstract The present paper adresses the issue of controlling the quality of surface in the case of a new sheet metal forming process by which various curved shells are formed without the help of expensive dies. The roughness of the surface which comes in direct contact with the punch at incremental sheet forming suffers an obvious worsening compared to the initial blank surface roughness. The present paper discusses the measuring of the roughness of parts obtained through the previously mentioned process and highlights the factors that influence it. There were taken into account the initial roughness of the punch, the punch diameter and the friction coefficient between the punch and the bla…
Contributions Regarding Incremental Forming Process of Bimetallic Sheets
2014
Incremental forming is a process with a high degree of novelty, so this paper describes first of all a series of theoretical principles of the incremental forming process. A main objective of the paper was the usage, as blanks in incremental forming process of bimetallic sheets. So the experimental researches have targeted the realising of parts with different shapes made from such type of blank. In the experimental researches was chosen as technological equipment for incremental forming the numerical controlled milling centre. The paper also present the tools used in incremental forming in order to obtain a hemispherical parts.
Robot-Forming - An Incremental Forming Process Using an Industrial Robot by Means of DELMIA Software Package
2013
The purpose of this research is to present an alternative method for manufacturing sheet metal parts using an asymmetric incremental forming process by means of an industrial robot. This method is based on designing, simulating and generating the toolpath for the tool attached to the robot using DELMIA software package. The proposed approach allows users to check for system collisions, robot joins limitations and singularity problems. After a comprehensive simulation of the movements of the robot is performed, the program code can be generated by means of a specific DELMIA function. The program can be used afterwards to control the robot during the experimental work. In order to demonstrate…
On-Line Control of Single Point Incremental Forming Operations through Punch Force Monitoring
2006
Abstract Among the innovative sheet metal forming processes, Single Point Incremental Forming (SPIF) represents the simplest and the cheapest one. Despite its relevant advantages, up to now no specific CAE tools for SPIF were developed and the tool trajectory is generally defined utilizing CAD/CAM software developed for machining applications. In the paper an innovative monitoring and control approach, aimed to define and in-process update the most relevant process parameters during an industrial SPIF operation, is proposed. The strategy utilizes as monitoring variable the punch force trend: a set of preliminary tests demonstrated, in fact, its suitability as “spy variable” of the process m…
Method for Manufacturing Custom-Shaped Prosthetic Parts from Titanium Alloys by Incremental Forming Using Industrial Robots
2014
The last decade has shown an increasing interest in a new class of forming processes known as Incremental Sheet forming (ISF). A possible application for this new procedure, targeted by the authors of this paper, is the manufacturing of custom-shaped prosthetic parts for use in various areas of human medicine. Such prostheses can have a functional role, when they target the replacing of a functional component of the human body, or an esthetic role, when they target the solving of problems related to the appearance of the human body. In this paper the authors aim to determine the strain hardening curves for the titanium alloy Ti6Al4V at room temperature and at 800°C. The incremental forming …
Springback evaluation in fully 3-D sheet metal forming processes
1997
Abstract In the modern manufacturing industries the knowledge and proper control of the sheet metal springback after forming is a fundamental aspect in the achievement of near net shape stamped parts. In this paper an effective springback prediction in some fully three-dimensional stamping processes is carried out. Such a prediction is based on a combined approach in which an explicit finite element code has been employed to simulate the forming phase while a traditional implicit procedure has been used to analyse the springback phase. The results obtained have been compared with a set of experimental tests and an excellent correlation between the predicted and experimental data has been fo…
A preliminary method for the numerical prediction of the behavior of air bubbles in the design of Air Cavity Ships
2016
Air-cavity ships (ACS) are advanced marine vehicles that use air injection under hull to improve the vessel’s hydrodynamic characteristics. Although the concept of drag reduction by supplying gas under the ship’s bottom was proposed in the 19th century by Froude and Laval, at this time there are not many systematic studies on this subject. This paper is a preliminary work with the purpose of being a basic tool for the design of the ACS with computational fluid dynamic methods. The study aims to conduct a series of computational tests to compare the numerical models of bubble with experimental data. The first step of this study was to investigate the behavior of free bubble in water, conside…
Measuring of Geometrical Precision of Some parts Obtained by Asymmetric Incremental Forming Process After Trimming
2007
Asymmetric Incremental Forming exalts the advantages of Incremental Forming process since no dies are strictly necessary. In this way complex geometries may be manufactured with a very simple clamping equipment. On the other hand, this characteristic determines some intrinsic drawbacks which penalise its industrial suitability; first of all, the dimensional control of the manufactured part is a still open point for researchers all over the world. Several approaches have been already proposed in the last years to solve the problem, resulting only in partial solutions. At the same time, up to now, the numerical simulation did not supply significant aid to the designers, due to the problem com…