Entwicklung eines neuartigen Eisenpulvers mit ungewöhnlichen Eigenschaften

The Development of a New Type of Iron Powder with Unusual Properties A short time ago the Mannesmann Research Institute developed a new, highly interesting and, in the meantime, patented product, namely an iron powder which does not feature the compact particle form of conventional powders but, instead, a more elongated, fibrous structure. This unique structure means that the powder has a number of unusual properties, e.g. an apparent density which can be regulated down to values below 0.7 g/cm³. It is expected that a number of important and possibly even unusual areas of application and uses will arise for this material which has been given the disignation “Super Light Iron Powder” (abbreviated code: “SL 200”).     

Einfluß von Gasadsorbaten auf die Eigenschaften eines Glühkatoden- Ionisationsmanometers mit axialer Emission nach CHEN und SUEN

The influence of adsorbed gases on the pressure reading of the axial emission ionization gauge according to CHEN and SUEN [1] was investigated in the UHV pressure range. The anodes of the investigated gauges were made from molybdenum and platinum. After exposure to argon, nitrogen, oxygen and hydrogen the ion current versus time characteristic was determined during pumpdown. The pressure reading of the axial emission gauge was compared with the readings of a commercial Bayard-Alpert gauge and an extractor gauge. After exposure to oxygen the gauge with the Mo-anode showed the largest deviation of the pressure readings of the gauges, while the gauge with Pt-anode showed strong deviations after oxygen and hydrogen exposure.     

Entwicklung und Einsatz eines PC-Programms für das Problem der Palettenbeladung mit Pharmaprodukten via Kartonverpackung

Zusammenfassung Das Beladen von Paletten mit Pharmapräparaten via Kartonverpackung stellt ein zweistufiges Packproblem dar. In diesem Beitrag werden drei konkrete Ausprägungen dieser allgemeinen Problemstellung behandelt. Es wird ein Lösungskonzept vorgestellt, in das neben einem bekannten heuristischen Lösungsverfahren für Lagenpackprobleme auch eigens für die konkreten Problemausprägungen entwickelte Verfahren integriert sind. Anschließend wird über Erfahrungen bei der Inhouse-Entwicklung und dem Einsatz eines PC-Programmes, durch welches das Lösungskonzept realisiert wurde, berichtet.     

Entwicklung eines hybriden Genetischen Algorithmus zur Tourenplanung

Subject of this paper is the development of a Genetic Algorithm (GA) for the Vehicle Routing Problem (VRP). At first a simple GA for the one-depot “standard” VRP with travel distance and capacity restrictions is presented. Then the GA is enhanced by hybridization. The performance of the enhanced GA is evaluated. Finally, the GA is modified to handle a cost function and some real world restrictions.     

Entwicklung eines wissensbasierten Informationssystems zur rechnerischen Lebensdauervorthersage

Development of a Knowledge Based Information System for Fatigue Life Prediction Summary The automotive manufacturer oppose the increasing competition with shorter development times and reduced costs. For this new development tools are necessary specially for the reduction of the experimental development expenditure. If computer aided fatigue life prediction methods supply reliable fatigue life values the experimental stage of development can be reduced. These computer simulations have to include internal experiences, of companies rules of improvement, facts, experimental results and the proved calculation methods. Together with the Adam Opel AG in Rüsselsheim the Fraunhofer-Institut für Betriebsfestigkeit has developed the knowledge based information systems FALIXS ( FA tigue LI fe E X pert S ystem) for fatigue life prediction of automotive components. It is an effective tool for the design fatigue resistant structures.     

Entwicklung eines Berechnungsverfahrens zur Behandlung viskoser reagierender Strömungen

Ohne Zusammenfassung     

Entwicklung und Validierung eines Kühlmittelsensors zur Bewertung der Korrosionsschutzwirkung

A sophisticated thermal management is one of the main subsystems that enables combustion engines with high power density. In this context the demands on coolants are also increasing. There has to be a certain level of corrosion protection to ensure the functionality of the cooling system. Hereafter the result of an electrochemical sensor development is presented. With the knowledge of analytical and electrochemical results a quick test for characterizing coolants corrosion protection has been developed and validated.     

Personalaufwandsplanung mit Hilfe eines erweiterten linearen Modells

Zusammenfassung Die Personalaufwandsplanung hat für die Unternehmensplanung eines Großunternehmens besondere Bedeutung. Orientierungspunkte dabei sind die gesamtwirtschaftliche Entwicklung und die Absatzmarktlage. Aufgabe ist die Ermittlung des Personalaufwands in Abhängigkeit von Belegschaftszahlen, Arbeitszeitbedarf usw. mit Hilfe eines allgemeinen Matrizenmodells, das auch nichtlineare Komponenten enthält. Das Modell ist routinemäßig im Einsatz.

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Summary Personnel expense planning is of great importance within big enterprise corporate planning. Orientation points are given from total economic development and from the market. The task is to find out personnel expense depending on personnel figures, work time requirement, etc. by implementation of a general matrix model. Non linear components are includet. The model runs in routine.

     

Bruchverhalten eines vergüteten und eines kaltgezogenen Stahles im Gleichgewichtszustand mit Druckwasserstoff

Fracture of Tempered and Cold Drawn Steel in Equilibrium with Compressed Hydrogen Tensile specimens are surface activated and stored in compressed hydrogen until equilibrium is attained. Charged and uncharged reference specimens are tested in air and in compressed hydrogen. The embrittlement of colddrawn steel (plenty of traps) is independent of strain rate and is caused mainly by the prior charging. Tempered steel (fewer traps) is not embrittled by charged hydrogen but by the effect of external hydrogen during the test. The degree of embrittlement decreases with increasing strain rate. In all cases of embrittlement there is in addition a strong notch sensitivity.     

Nachrechnung der Leistungsparameter eines Sicherheitsventils mit ANSYS CFX

The effect of the grid fineness and that of the choice of the turbulence model are discussed in this paper concerning the reproduction of air mass flow rates in two small size safety valves for relieving pressures between 4 and 40 bar. The results show that in both valves the fineness of the grid is the key factor and that the effect of the turbulence model is secondary.     

Entwicklung eines Universal Tractor Transmission Oil (UTTO) auf Basis nachwachsender Rohstoffe

Development of a Universal Tractor Transmission Oil (UTTO) based on renewable raw materials The 2^nd generation of an environmentally friendly fluid for vehicles with a common oil tank for transmission and hydraulics was developed in a governmentally funded research project. The fluid consists to about 75 % of native rapeseed oil. The boundary conditions as well as the intentions and goals of this new development will be explained as well as the reasons which led to this unique lubricant conception. The fluids properties will be illustrated by experimental investigations and their results. The discussion based on the comparison of results achieved with BIO‐HY‐GARD II and parallel tests with reference fluids enables the validation of different lubricants technology performance as well as the verification of the achieved progress with this new development.     

Entwicklung eines Osteosyntheseverfahrens zur winkel- und rotationsstabilen Versorgung kopfnaher Brüche des Oberarmes

Development of an osteosynthetic technique for internal fixation of proximal humerus fractures with angle and rotation stability With a share of 4 to 5 % of all fractures seen during in-patient treatment, fractures of the proximal humerus are a common injury playing a major role in the clinical routine. A major part of proximal humerus fractures are to be treated in a conservative and functional way on condition that they show solid impaction or minimal displacement. However unstable displaced fractures are not suited for conservative treatment but require fixation provided by surgery. The currently used minimal implants such as Kirschner wires, wire loops, PDS tension bands and lag screws often cause considerable irritation of the sorrounding soft tissue and rarely reveal sufficiently stable results. The also used common T-plates, bended and rigged up cloverleaf plates or a combination of one-third-tubular plates cannot be accepted as satisfactory because they are oversized in width and thus tend to cause impingement against the acromion during arm abduction by the patient. Furthermore, screws may not find a stable hold in the osteoporotic bone of older patients, loose their grip and hence give rise to implant failure. Facing an unsatisfactury situation in the clinical routine it was the aim to develop a completely new implant designed with special regard for proximal humerus injury. Essential demands on the new implant were defined as follows: – absolutely stable internal fixation enabling active mobilisation and providing safe rotation and angle stability – reliable refixation of fractured tubercels – perfect adjustment to the anatomy without relevant muscle detachment – no implant-generated restriction of the degree of movement in the shoulder joint – simple and safe operation technique with a minimum of soft tissue harm – simple implant explantation – high biocompatibility of implant materials Based on these demands the new implant was designed as a hybrid construction between to an internal fixator and a neutralization plate. Hence the implant is called a fixator plate. The head fragment of the humerus is engaged by two stable screws angled at 37,5 ° towards the humerus axis which are fixed in the proximal part of the humerus fixator plate. The shaft fragment is engaged by common cortex screws set in the lower part of the humerus fixator plate. The new implant type was investigated up to now in 11 patients, in 10 of which absolutely stable internal fixation was achieved. Within a few days after the operation most patients were able to do simple chores such as combing hair and dressing unassistedly. The first clinical investigations of the novel fixator plate provide essential advances in the treatment of instable proximal humerus fractures.     

Die numerische Behandlung eines Schrankenverfahrens mit Anwendung auf axialsymmetrisches Stauchen

Zusammenfassung Das Stauchen einfacher axialsymmetrischer Proben wird mit Hilfe des Verfahrens von der oberen Schranke untersucht. Die angegebene numerische Methode, ein iteratives Ritz-Verfahren für mehrparametrige Ansatzfunktionen, liefert bessere Schranken für die Stauchkraft als vergleichbare Verfahren in der Literatur. Zudem erhält man eine gute Approximation des momentanen Geschwindigkeitsfeldes und kann damit den Verlauf der Umformung schrittweise verfolgen. Das angegebene Verfahren läßt sich durch Wahl geeigneter Ansatzfunktionen sinnvoll auf andere Umformprozesse anwenden.

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Numerical Evaluation of an Upper Bound Theorem with Application to Axisymmetric Compression

Summary The compression of simple axisymmetric specimen is treated by means of the upper bound theorem. An iterative Ritz-method, proposed in this paper, yields better upper bound loads than comparable methods known in literature. Moreover, a good approximation of the instantaneous velocity field is derived. Using this field the non-stationary deformation is examined step by step. By choosing a proper system of functions for the velocity field the given method well applies to other forming processes.

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Betriebsnahe Schadenserkennung mit Hilfe der holografischen Interferometrie und eines Doppelimpulslasers

Holographic Investigation on Failure Mechanisms in Homogenous Materials There is a relation between defects occuring in the wall material of pressurized equipment and the deformation of wall surface under load. If the deformation at the surface exceeds 35 nm, it is possible to use holographic interferometry for detection. The object is illuminated by a double pulsed ruby-laser. The frequency of the flashes is very large. Therefore it is not necessary to use of a stabilized holographic equipment. In this way it is possible to detect damage progression in the material of equipment during operation with non-destructive methods. Usually the severity of a failure is characterized by the apparent perturbation of its holographic fringe pattern. The method is applicable to pressure vessels, if the holographic taken fringe pattern is related quantitatively to the size of a failure. In this report we present the experimental results which give the relation between the perturbation of the holographic fringes and the size of different kinds of failures. The size of the smallest detectable failure is smaller the critical size of a flaw in the material.     

Interdisziplinäre Entwicklung eines künstlichen Kniegelenks (Kniegelenks-Endoprothese) in Kunststoff-Metall-Kombinationsbauweise

Interdisciplinary development of an artificial knee joint endoprosthesis as a “combined plastic-metal-construction” . Endoprostheses for joints of the human locomotor apparatus under certain indications serve as permanent implants for eliminating painful changes of joints (e. g. arthrosis) as well as for restoration of essential joint functions (e. g. knee bending). The complexe correlation of biological-physiological factors and problems concerning materials and nature of load requires the adequate interdisciplinary co-operation of orthopaedic surgeons and engineers. On example of the prototype development of a total prosthesis for the knee joint the biomechanical conditions are sketched by means of the kinematics, statics, dynamics and tribology of normal natural joints (hip and knee) as a basis for the derivation of compensational functions. Already existing models are discussed, and the conception as well as the construction and production of the prototype of an artificial knee joint (“hinge joint-principle”) as a combined “plastic-metal-system” is described.     

Entwicklung und Herstellung eines neuartigen,bauartzugelassenen Tankcontainers für Bortrifluorid und andere hochverdichtete Gase

Development and construction of a new type, design-approved tank container for boron-tri-fluoride and other highly compressed gases A new type of tank container was developed and tested during a period of about two years and approved by the Bundesanstalt für Materialprüfung (BAM) for transporting boron-tri-fluoride and nitrogen. The total weight of this tank container is about 1500 kg and its capacity about 450 litres. This tank container - in comparison to single pressure gas bottles - allows the transport of larger quantities and shall replace gas bottles or bottle batteries in a safe way or shall be used as a supplement to them. Since the container is mounted on a supporting structure, it can be moved by fork lifters, fork-lift trucks or cranes. The transport can be made by truck, rail or ship.