Analytical Strength Assessment Sintered Steel | Buch

Analytical Strength Assessment of Components Made of Sintered Steels
1st Edition 2024
46 Seiten

The FKM Guideline “Analytical strength assessment of components made of sintered steels” is the first publicly available, engineer‑ready design rule dedicated to pressed and sintered steels and fully aligned with the established FKM framework for local, elastic stress assessment. It closes a long‑standing gap: while wrought and cast steels are well covered, powder‑metallurgy (PM) components have lacked a coherent, validated assessment method.

The guideline enables reliable static and fatigue verification using only two material inputs: Vickers hardness (HV10) and density. From these values, all necessary properties and influence factors are derived so that the degree of utilization for static and fatigue strength can be evaluated. In addition to hardness and density, the method requires only a linear‑elastic finite‑element analysis to obtain local principal or von Mises stresses and their distribution.

The assessment approach is grounded in an exceptional database – over 22,000 fatigue data points and 64 × 2 static tests – covering 12 widely used sintered steel families and 35 specimen geometries. This breadth supports confident application across typical hardness and density ranges and complex local stress states. 

Engineers benefit from minimal inputs, fast FE‑based workflows, reduced testing effort, and consistent, traceable decisions. The guideline is ideal for automotive and machinery applications, integrates seamlessly with existing CAE processes, and helps avoid overdesign while safeguarding durability. In short, it turns PM component design into a data‑guided, efficient, and robust process.

Contents
0 General
0.1 Scope
0.2 Technical background
0.3 Required assessments
0.4 Stresses and stress components
0.5 Material data
0.6 Safety factors
0.7 Calculation procedure  
1 Assessment of static strength
1.1 General
1.2 Acting stresses
1.3 Material properties.
1.3.1 General
1.3.2 Estimation of material properties
1.4 Design parameters
1.5 Component strength
1.6 Safety factors
1.6.1 General
1.6.2 Load factor
1.6.3 Material factor  
1.7 Assessment
1.7.1 General
1.7.2 Assessment
2 Assessment of fatigue strength
2.1 General  
2.1.1 Characteristic values of stress
2.1.1.0 General
2.1.1.1 Stress components
2.1.1.2 Stress spectrum and S-N curve
2.1.1.2.1 Parameters of the stress spectrum  
2.1.1.2.2 Parameters of the S-N curve
2.2 Material properties
2.2.0 General
2.2.1 Fully reversed reference fatigue strength
2.3 Design parameters
2.3.0 General
2.3.1 Design factors
2.3.1.1 Highly stressed volume  
2.3.1.2 Surface treatment factors
2.4 Component strength
2.4.0 General
2.4.1 Component fatigue strength
2.4.2 Mean stress evaluation
2.4.2.0 General  
2.4.2.1 Maximal amplitude assessment
2.4.2.2 Equivalent amplitude assessment
2.4.2.3 Mean stress sensitivity  
2.4.2.4 Fatigue strength diagram
2.4.2.5 Mean stress factor
2.4.2.6 Single mean stress
2.4.3 Variable amplitude fatigue strength  
2.4.3.0 General  
2.4.3.1 Evaluation of damage equivalent stress  
2.4.3.2 Limitation of maximal amplitude
2.4.3.3 S-N curve  .
2.4.3.4 Calculation for constant amplitude stress
2.4.3.5 Calculation for variable amplitude stress
2.4.3.6 S-N curve for variable amplitude loading
2.5 Safety factors
2.5.0 General
2.5.1 Components
2.5.2 Total safety factor
2.6 Assessment  
2.6.0 General
2.6.1 Degree of utilization  
3 Examples
3.1 Strength assessment of a synchronizer hub
3.1.1 Description
3.1.2 Input data
3.1.3 Assessment of static strength
3.1.4 Assessment of cyclic strength
3.2 Strength assessment of a conrod
3.2.1 Input data
3.2.2 Assessment of static strength
3.2.3 Assessment of cyclic strength
4 Database
4.1 Analytically derived fatigue strength
4.2 Raw data for deriving Eq. 2.3.1.2
4.3 Database for Haigh-diagram