scholarly journals Investigations of the Influence of a Superimposed Oscillation on the Fatigue Strength

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1274
Author(s):  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Daniel Rosenbusch ◽  
Philipp Müller
Keyword(s):  
Fatigue Strength ◽  
Surface Quality ◽  
Collaborative Research ◽  
Mechanical Vibration ◽  
Research Centre ◽  
Term Strength ◽  
Forming Process ◽  
Vibration Resistance ◽  
Threshold Range

Within the scope of the transregional collaborative research centre TCRC73, the effects of an oscillation superimposed forming process for the production of a demonstrator component are investigated. Previous studies in this field were limited to a consideration of the process-related parameters such as the influence of the plastic work and the friction or the component-related parameters such as the influence of the surface quality and the mold filling. This research concentrates on the consideration of the mechanical vibration resistance of components that were manufactured superimposed oscillated. For this purpose, Wöhler tests are conducted in which the fatigue strength of superimposed oscillation pre-stretched test samples and oscillation-free pre-stretched test samples are investigated. First, Wöhler curves are generated in the tensile threshold range for tensile samples made out of the steels DC04 and DP600. Subsequently, tensile specimens are pre-stretched superimposed oscillated and oscillation-free. These specimens are subjected to a tensile threshold load until they break. The influence of the superimposed oscillation forming on the long-term fatigue of components is derived from the comparison of the bearable load cycles. Investigations of the microstructure of the specimens are conducted in order to draw conclusions about the influence on the long-term strength.

Influence of Manufacturing Process on the Fatigue Strength of Gears

2014 ◽  
Vol 1018 ◽  
pp. 269-276
Author(s):  
Andrea Reiß ◽  
Ulf Engel
Keyword(s):  
Fatigue Strength ◽  
Surface Quality ◽  
Fatigue Behavior ◽  
High Surface ◽  
Research Work ◽  
Dimensional Accuracy ◽  
Cold Forging ◽  
Hardness Distribution ◽  
Forming Process ◽  
High Surface Quality

With cold forging processes it is possible to produce parts characterized by high strength, high dimensional accuracy and high surface quality. In order to optimize the forming process and to be able to use the advantages of cold forging specifically and combined, it is necessary to find correlations between manufacturing parameters on the one side, strength and other properties like hardness distribution and surface quality of the component on the other side. The research work covered in this paper focuses on the correlation of the components properties influenced by its manufacturing history and their fatigue strength. The used component is a gear produced by a lateral cold forging process. For the investigations an experimental setup has been designed. The aim for the design of the setup is to reproduce the real contact condition for the contact of two gears. To obtain different component properties the production process of the gear was varied by producing the parts by a milling operation. First of all, the components’ properties, for example hardness distribution, remaining residual stresses, orientation of fibers and surface quality, were determined. The components’ fatigue behavior was determined using a high frequency pulsator and evaluated in terms of finite life fatigue strength and fatigue endurance limit. These examinations were used to produce Woehler curves for the differently manufactured components with a certain statistical data analysis method.

Investigation on the Influence of Manufacturing Parameters on the Fatigue Strength of Components

2013 ◽  
Vol 554-557 ◽  
pp. 280-286 ◽  
Author(s):  
Andrea Reiss ◽  
Ulf Engel ◽  
Marion Merklein
Keyword(s):  
Fatigue Strength ◽  
Surface Quality ◽  
Fatigue Behavior ◽  
High Surface ◽  
Research Work ◽  
Cold Forging ◽  
Hardness Distribution ◽  
Forming Process ◽  
High Surface Quality ◽  
Manufacturing Parameters

With cold forging processes it is possible to produce parts characterized by high strength, high dimensional accuracy and high surface quality. In order to optimize the forming process and to be able to use the advantages of cold forging specifically and combined, it is necessary to find correlations between the manufacturing parameters, the strength and the properties, like hardness distribution and surface quality, of the component. The research work covered in this paper focuses on the influence of the components properties influenced by its manufacturing history on their fatigue strength. The used component is a flange hub, produced by a four-stage cold forging process. To obtain different component properties the production process of the hub was varied for example by changing the heat treatment or by producing the parts by turning process. First of all, the components’ properties, for example hardness distribution, remaining residual stresses, orientation of fibers and surface quality, were determined. Moreover, a special experimental setup for the fatigue tests has been designed. The components’ fatigue behavior was determined using a high frequency pulsator and evaluated in terms of finite life fatigue strength and fatigue endurance limit. These examinations were used to produce Woehler curves for the differently manufactured components with a certain statistical data analysis method.

scholarly journals Introduction to tailored forming

2021 ◽  
Author(s):  
B.-A. Behrens ◽  
J. Uhe
Keyword(s):  
Collaborative Research ◽  
Lightweight Design ◽  
Production Quality ◽  
Research Centre ◽  
Lightweight Construction ◽  
Forming Process ◽  
Process Chains ◽  
Finishing Processes ◽  
Tailored Forming ◽  
Joining Process

AbstractIn recent years, the requirements for technical components have been increasing steadily. This development is intensified by the desire for products with lower weight, smaller size and extended functionality, but at the same time higher resistance against specific loads. Mono-material components manufactured according to established processes reach their limits regarding conflicting requirements. It is, for example, hardly possible to combine excellent mechanical properties with lightweight construction using mono-materials. Thus, a significant increase in production quality, lightweight design, functionality and efficiency can only be reached by combining different materials in one component. The superior aim of the Collaborative Research Centre (CRC) 1153 is to develop novel process chains for the production of hybrid solid components. In contrast to existing process chains in bulk metal forming, in which the joining process takes place during forming or at the end of the process chain, the CRC 1153 uses tailored semi-finished workpieces which are joined before the forming process. This results in a geometric and thermomechanical influence on the joining zone during the forming process which cannot be created by conventional joining techniques. The present work gives an overview of the CRC and the Tailored Forming approach including the applied joining, forming and finishing processes as well as a short summary of the accompanying design and evaluation methods.

scholarly journals Methods and Technologies for Research- and Metadata Management in Collaborative Experimental Research

2018 ◽  
Vol 885 ◽  
pp. 170-183
Author(s):  
Nils Preuss ◽  
Georg Staudter ◽  
Moritz Weber ◽  
Reiner Anderl ◽  
Peter F. Pelz
Keyword(s):  
Experimental Research ◽  
Collaborative Research ◽  
Web Application ◽  
Experimental Studies ◽  
Independent Solution ◽  
Research Centre ◽  
Data Repository ◽  
Metadata Management ◽  
Research Environments

Newly developed technologies and methods for the purpose of controlling uncertainty in technical systems must be proven and validated against reliable experimental studies. The availability of descriptive metadata is mandatory to enable long term usability and sharing of such experimental research data. This article introduces a concept for a software independent solution for managing data in collaborative research environments. The proposed approach leverages the advantages of capturing metadata in a uniform, modular data structure and providing software independent access to a centralized data repository as well as its contents by means of a web-application. The article presents a prototype implementation of the proposed approach and discusses its application on the demonstrator test rig of a collaborative research centre in the field of mechanical engineering.

Subcritical Crack Growth and Long-Term Strength in Rock and High-Strength and Ultra Low-Permeability Concrete

2009 ◽  
Vol 58 (6) ◽  
pp. 525-532 ◽  
Author(s):  
Yoshitaka NARA ◽  
Masafumi TAKADA ◽  
Daisuke MORI ◽  
Hitoshi OWADA ◽  
Tetsuro YONEDA ◽  
...  
Keyword(s):  
Crack Growth ◽  
Subcritical Crack Growth ◽  
High Strength ◽  
Low Permeability ◽  
Term Strength

Schwingungsüberlagertes Axialformen/Superimposed Oscillated Axial Forming

2020 ◽  
Vol 110 (11-12) ◽  
pp. 838-843
Author(s):  
Philipp Müller ◽  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Hendrik Vogt ◽  
Daniel Rosenbusch ◽  
...  
Keyword(s):  
Surface Quality ◽  
Economic Importance ◽  
Combined Effect ◽  
Wird Eine ◽  
Forming Force ◽  
Forming Process ◽  
Forming Technology ◽  
Great Economic Importance ◽  
Gear Geometry

Techniken zur Steigerung der Formgebungsgrenzen in der Umformtechnik sind von hoher wirtschaftlicher Bedeutung. In dieser Arbeit wird eine Schwingungsüberlagerung im Krafthauptfluss eines Axialformprozesses zur Ausprägung einer Verzahnungsgeometrie untersucht. Die Auswirkungen der Schwingung auf die erzielbare Ausfüllung der Zahnkavitäten werden analysiert sowie die Parameter Schmierung und Oberflächengüte der Halbzeuge in ihrer kombinierten Wirkung untersucht. Es konnte eine Reduzierung der mittleren Umformkraft sowie eine Erhöhung der Formfüllung festgestellt werden. Techniques for extending the production limits in forming technology are of great economic importance. In this research, a superimposed oscillation in the main force flow of an axial forming process to form an axial gear geometry is investigated. The effects of the superimposed oscillation on the achievable form-filling of the tooth cavities are analyzed and the parameters lubrication and surface quality of the semi-finished products are investigated in their combined effect. A reduction of the averaged forming force as well as an increase of the form-filling could be achieved.

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