Analytical Strength Assessment 7th. Ed. 2020 EN | Print

7th Edition 2020
232 pages

The actual 7th edition of the FKM-Guideline “Analytical Strength Assessment for Machine Components” has been completely revised. Hence, a listing of all changes is not manageable.
The following important changes were carried out in the calculation algorithm:
-  ductility now clearly referred to elongation at rupture,
-  new parameters for long-term temperature factors,
-  addition of elastic strain to the total critical strain for calculation of section factor,
-  introduction of the hardening factor,
-  static strength values of welded components with reference to Eurocode 9,
-  enhanced stress definition for general possibility for application of critical plane approach in fatigue,
-  parallel description of fatigue strength assessment via maximal stress amplitude and via equivalent stress amplitude,
-  adjusted parameters for the Kt/Kf-ratio according to Siebel & Stieler for aluminium castings
-  extended the applicability of the coating factor to zincplated steel
-  limitation of the maximum amplitude formulated with considering mean stress and mean stress sensitivity,
-  slight modifications in S-N curve system,
-  new formulated sign rule for combined utilisation,
-  clarification of decisive result of assessment (single utilisations vs. combined utilisation),
-  complete revision of material tables,
-  new material group "Ausferritic cast iron with nodular graphite" (ADI),
-  new table of fatigue notch factors for press-fitted shafts according to DIN 743,
-  new formulation of fatigue strength assessment of welded components on base of notch stresses or effective stresses,
-  introduction of specific surface treatment factors for weld post-treatment according to IIW.
The description for overload cases F3 and F4 has been removed because of their rather rare practical application.
Their use in accordance with the sixth edition of the FKM Guideline is still permissible.

Contents

0 General
0.1 Scope
0.2 Technical basics
0.3 Required Assessments
0.4 Stresses and component types
0.5 Calculation procedure
1 Static strength assessment with nominal stresses
1.0 General
1.1 Characteristic values of stress
1.2 Material properties
1.3 Design parameters
1.4 Component strength
1.5 Safety factors
1.6 Assessment
2 Fatigue strength assessment with nominal stresses
2.0 General
2.1 Characteristic values of stress
2.2 Material properties
2.3 Design parameters
2.4 Component strength
2.5 Safety factors
2.6 Assessment
3 Static strength assessment with local stresses
3.0 General
3.1 Characteristic values of stress
3.2 Material properties
3.3 Design parameters
3.4 Component strength
3.5 Safety factors
3.6 Assessment
4 Fatigue strength assessment with local stresses
4.0 General
4.1 Characteristic values of stress
4.2 Material properties
4.3 Design parameters
4.4 Component strength
4.5 Safety factors
4.6 Assessment
5 Annexes
5.1 Material tables
5.2 Stress concentration factors
5.3 Fatigue notch factors
5.4 Fatigue classes for welded components made of steel and aluminium alloys
5.5 Estimation of fatigue limit of surface treated components
5.6 Experimental determination of component strength values
5.7 Load assumptions
6 Examples
6.1 Shaft shoulder
6.2 Cast component
6.3 Compressor flange made of GJL
6.4 Welded perforated rod
6.5 Welded aluminium T-profile
6.6 Welded aluminium component

 The guideline was written on behalf of the Forschungskuratorium Maschinenbau e.V. (FKM) under the leadership of IMA Materialforschung and Application Technology GmbH by:

Prof. Dr.-Ing. Roland Rennert, IMA Materialforschung und Anwendungstechnik GmbH, Dresden
Prof. Dr.-Ing. Eckehard Kullig, HTW University of Applied Sciences for Technology and Economics, Dresden
Prof. Dr.-Ing. Michael Vormwald, TU Darmstadt, Department of Mechanics of Materials
Prof. Dr.-Ing. Alfons Esderts, TU Clausthal, Institute of Mechanical Plant Engineering and Structural Durability
Dr.-Ing. Michael Luke, Fraunhofer Institute for Mechanics of Materials, Freiburg