Solidification Time Estimation and Simulation - In Case of HPDC

2010 ◽  
Vol 649 ◽  
pp. 467-472 ◽  
Author(s):  
Gabor Leranth
Keyword(s):  
Numerical Simulation ◽  
Metal Forming ◽  
Thermal Conditions ◽  
Time Estimation ◽  
Anglo Saxon ◽  
Casting Method ◽  
Technical Literature ◽  
German Speaking ◽  
Long Time ◽  
Cast Parts

Since cast parts are used by the mankind -and the casting method should be one of the oldest metal forming technologies- the foundrymen struggle with various kind of difficulties. The most elementary ones are thermal problems during pouring. The basic condition, filling the mould before the metal solidifies to get the whole required shape, underlies primarily the thinnest wall within the casting and the thermal conditions. The empiric, experience-based knowledge was for a long time the single clue at the practical work with castings. Chvorinov, in German-speaking publications also written as Chworinoff, summarized and through his theoretical as well as experimental work complemented the knowledge of his time concerning the estimation of solidification development in sand-casted steel parts. His theory –expressed with the certainly best known formula in this speciality- was later expanded, modified and adapted to new scientific informations, although in a different way regarding the German-speaking respectively Anglo-Saxon technical literature. Nowadays, in time of more correct predictions supported through modern tools, estimation formulas are still very useful, acting as a preliminary stage of the design and development. Numerical simulation, in effect the efficient instrument for the subsequent steps of the processing, can also help to make the basic approximations more accurate, but it has his own possible traps as well.

scholarly journals To the Delineation of “Depersonalization Allied” Phenomena: J. Reil’s and E. von Feuchtersleben’s Concepts of “General Feeling” (Coenaesthesis)

Psychiatry ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 100-112
Author(s):  
N. Yu. Pyatnitskiy
Keyword(s):  
Mental Disorders ◽  
Medical School ◽  
Anglo Saxon ◽  
Mental Diseases ◽  
Xixth Century ◽  
General Feeling ◽  
German Speaking ◽  
Long Time ◽  
Muscular Temperature ◽  
Temperature And Pressure

The origin of the term and notion of “coenaesthesis” of German-speaking medical school was analyzed. Whereas in Germany the term “Coenaesthesis” was presumably fi rst used by J. Reil’s pupil Ch.F. Huebner (1794) in his written in Latin dissertation and the concept that considered the changes in “general feeling” as a ground for some psychiatric disorders was elaborated by J. Reil (1799, 1805), in Russia the similar ideas were expressed by A.F. Solnzev (1825) in his also written in Latin dissertation as D.D. Fedotov and V.G. Ostroglazov indicate. It may be assumed that the Scotch doctor A. Crichton (Alexander Kreiton in Russian transcription) contributed to the propagation of the concept of “Coenaesthesis” from Germany to Russia, due to his account of German concept of “General feeling” in his “Inquiry into the nature and origin of mental derangement” (1798) and succeeding fi fteen years work in Russia. In German-speaking psychiatry the Reil’s concept of “Coenaesthesis” was farther developed by Austrian doctor and psychiatrist E. von Feuchtersleben (1845), who underlined its meaning not only in hypochondrial but also in hysterical disorders and actively used the term “Coenaesthesis” along with the German term “general feeling”; the concept of general feeling is also refl ected in the famous W. Griesinger’s “Pathology and therapy of mental diseases”. In connection with the following separation from general feeling the muscular, temperature and pressure feelings its notion got narrowed as also the circle of mental disorders that was considered as determined by the different changes in general feeling. That is noticeable in German-speaking psychiatry in the concepts of R. von Kraft-Ebing and E. Kraepelin; while H. Schuele did not use the notion of general feeling at all. In Russia A.F. Solnzev’s concept of Coenaesthesis was for a long time forgotten, but in France in the second half of the XIXth century psychologist and philosopher Th. Ribot opened “cenesthesie” anew. In anglo-saxon psychiatry the disorders of general feeling were never considered as a special psychopathological syndrome (with the exception of its presentation by A. Crichton).

Multi-Step Forward Finite Element Method for the Numerical Simulation of Sheet Metal Forming

2011 ◽  
Vol 474-476 ◽  
pp. 251-254
Author(s):  
Jian Jun Wu ◽  
Wei Liu ◽  
Yu Jing Zhao
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Mapping Method ◽  
Constitutive Relationship ◽  
Element Method

The multi-step forward finite element method is presented for the numerical simulation of multi-step sheet metal forming. The traditional constitutive relationship is modified according to the multi-step forming processes, and double spreading plane based mapping method is used to obtain the initial solutions of the intermediate configurations. To verify the multi-step forward FEM, the two-step simulation of a stepped box deep-drawing part is carried out as it is in the experiment. The comparison with the results of the incremental FEM and test shows that the multi-step forward FEM is efficient for the numerical simulation of multi-step sheet metal forming processes.

Comparison between an Advanced Numerical Simulation of Sheet Incremental Forming Using Adaptive Remeshing and Experimental Results

2013 ◽  
Vol 554-557 ◽  
pp. 1375-1381 ◽  
Author(s):  
Laurence Giraud-Moreau ◽  
Abel Cherouat ◽  
Jie Zhang ◽  
Houman Borouchaki
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Sheet Metal ◽  
Metal Forming ◽  
Tool Path ◽  
Incremental Forming ◽  
Computation Time ◽  
Experimental Results ◽  
Forming Process ◽  
Adaptive Remeshing

Recently, new sheet metal forming technique, incremental forming has been introduced. It is based on using a single spherical tool, which is moved along CNC controlled tool path. During the incremental forming process, the sheet blank is fixed in sheet holder. The tool follows a certain tool path and progressively deforms the sheet. Nowadays, numerical simulations of metal forming are widely used by industry to predict the geometry of the part, stresses and strain during the forming process. Because incremental forming is a dieless process, it is perfectly suited for prototyping and small volume production [1, 2]. On the other hand, this process is very slow and therefore it can only be used when a slow series production is required. As the sheet incremental forming process is an emerging process which has a high industrial interest, scientific efforts are required in order to optimize the process and to increase the knowledge of this process through experimental studies and the development of accurate simulation models. In this paper, a comparison between numerical simulation and experimental results is realized in order to assess the suitability of the numerical model. The experimental investigation is realized using a three-axis CNC milling machine. The forming tool consists in a cylindrical rotating punch with a hemispherical head. A subroutine has been developed to describe the tool path from CAM procedure. A numerical model has been developed to simulate the sheet incremental forming process. The finite element code Abaqus explicit has been used. The simulation of the incremental forming process stays a complex task and the computation time is often prohibitive for many reasons. During this simulation, the blank is deformed by a sequence of small increments that requires many numerical increments to be performed. Moreover, the size of the tool diameter is generally very small compared to the size of the metal sheet and thus the contact zone between the tool and the sheet is limited. As the tool deforms almost every part of the sheet, small elements are required everywhere in the sheet resulting in a very high computation time. In this paper, an adaptive remeshing method has been used to simulate the incremental forming process. This strategy, based on adaptive refinement and coarsening procedures avoids having an initially fine mesh, resulting in an enormous computing time. Experiments have been carried out using aluminum alloy sheets. The final geometrical shape and the thickness profile have been measured and compared with the numerical results. These measurements have allowed validating the proposed numerical model. References [1] M. Yamashita, M. Grotoh, S.-Y. Atsumi, Numerical simulation of incremental forming of sheet metal, J. Processing Technology, No. 199 (2008), p. 163 172. [2] C. Henrard, A.M. Hbraken, A. Szekeres, J.R. Duflou, S. He, P. Van Houtte, Comparison of FEM Simulations for the Incremental Forming Process, Advanced Materials Research, 6-8 (2005), p. 533-542.

scholarly journals St Bruno of Querfurt: the Missionary Vocation

2009 ◽  
Vol 14 (1) ◽  
pp. 41-52
Author(s):  
Darius Baronas
Keyword(s):  
Community Life ◽  
Anglo Saxon ◽  
Close Link ◽  
Long Time ◽  
Noteworthy Feature

The aim of this article is to reconstruct the picture of the missionary as it appears in the writings of St Bruno of Querfurt (d.1009). Scholars have noted for a long time that St Bruno saw a very close link between the missionary calling and martyrdom. From his writings it becomes quite clear that he personally had a desire to suffer martyrdom. Such a desire, however, did not have much in common with a precipitous drive to become a martyr. He saw it, rather, as a crown awaiting the missionary at the end of a long road of self-mortification and self-renunciation. He put forward for himself and for his ascetic readers a three-stage course of perfection: community life (coenobium) for beginners, a life in seclusion (eremus) for the advanced, and the mission to the pagans for the most perfect. Such a course of ascetic life was characteristic of Irish and Anglo-Saxon monks (in the sixth-eighth centuries) whose pilgrimages tended to evolve into missionary trips among the pagans. In the context of medieval missionaries St Bruno stood out as he personally pondered over this issue in a methodological fashion. In the eyes of the saint, preparation for missionary activities should lead to rational martyrdom (rationale martyrium) in which one could hardly fail to notice the original notion of martyrdom as a witness to the Faith. Another noteworthy feature of St Bruno’s thoughts may be his insistence on having a papal licence to conduct evangelization, which was not asked for usually in his days. Thus, he may be viewed not only as a devotee of St Peter and his successors, but also as an advocate of papal missions, which tended to be most promising to newly converted rulers and their subjects.

scholarly journals The Role of Metamorphosis in Anglo- Saxon Ballads, Albanian Ballads and Frontier Warrior Songs

2020 ◽  
Vol 6 (1) ◽  
pp. 28
Author(s):  
Danela Bala Kraja
Keyword(s):  
Social Development ◽  
Human Being ◽  
Anglo Saxon ◽  
Negative Effects ◽  
Form Of Life ◽  
Long Time ◽  
Ending Process

This article aims to point out the role of metamorphosis in Anglo- Saxon ballads, Albanian ballads and frontier warrior songs. The Anglo- Saxon ballads and Albanian frontier warrior songs and ballads came into existence a long time ago and they had a certain number of influences which as a result had their great impact on their creation, development and circumstances when and where they were composed. They were created as a consequence of some special historical, cultural and social development. It has to be emphasized that those influences were of different character and size such as human, non-human or divine ones and the compositions of songs or ballads were inspired and conditioned by a lot of circumstances. Metamorphosis is used to express that never- ending process and of course it is transforming. The changes are either positive or negative and consequently people may perceive different good or bad feelings. It is related to the magic world and the unrealistic one and sometimes it is a beautiful feeling when a human being transforms into a rose and showing a form of life continuation after death but in many cases it transforms into a non-desirable object or animal. It is a quick transformation from one thing to another and it may have either positive or negative effects on the audience.

Optimization for Stamping Process Parameters of Front Fender Based on Numerical Simulation Technology

2010 ◽  
Vol 102-104 ◽  
pp. 232-236 ◽  
Author(s):  
Zhi Feng Liu ◽  
Qi Zhang ◽  
Wen Tong Yang ◽  
Jian Hua Wang ◽  
Yong Sheng Zhao
Keyword(s):  
Numerical Simulation ◽  
Sheet Metal ◽  
Process Parameters ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Simulation Analysis ◽  
Explicit Method ◽  
Simulation Technology ◽  
Stamping Process ◽  
Automotive Panel

According to the characteristic which is more and difficult to determine about the automotive panel forming factors, based on the dynamic explicit method, taking the typical automobile front fender for example, do the simulation analysis by using of DYNAFORM. On the premise of taking springback factors into account, analog the best stamping process parameters has been optimized from the analysis results after simulation such as sheet metal forming limited drawing(FLD)and sheet metal thinning drawing.

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