Jan Schubnell
Fraunhofer Society
Composite materialMaterials scienceWeldingResidual stressHardening (computing)
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Publications 7
#1J. Schubnell (Fraunhofer Society)H-Index: 1
#1Jan Schubnell (Fraunhofer Society)H-Index: 3
Last. Volker Schulze (KIT: Karlsruhe Institute of Technology)H-Index: 27
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Abstract In the present study, the effect of process-induced residual stress and work hardening was separately analyzed to describe the fatigue life improvement by High Frequency Mechanical Impact (HFMI) treatment. For this purpose, blunt notched specimens made of mild steel S355J2+N and high strength steel S960QL were HFMI-treated under different mechanical pre-stress conditions. In that way, the effect of residual stress and work hardening could be separated. The generated residual stress stat...
2 CitationsSource
#1Jan Schubnell (Fraunhofer Society)H-Index: 3
#2C. Eichheimer (Fraunhofer Society)H-Index: 1
Last. Majid Farajian (Fraunhofer Society)H-Index: 7
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Abstract The High Frequency Mechanical Impact (HFMI) process is a comparably new, manually-driven machine hammer peening (MHP) process applied to increase the fatigue performance of metallic components. The HFMI-process is characterized by a large number of impacts, also when the tool was used with a high feed rate. This leads to a fast saturation and highly plastic deformation at the surface layer. Experimental investigations of the surface topography, near-surface residual stresses, and work h...
1 CitationsSource
#1Jan Schubnell (Fraunhofer Society)H-Index: 3
#2Matthias Jung (Fraunhofer Society)H-Index: 12
Last. J. Baumgartner (Fraunhofer Society)H-Index: 9
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The joining by welding processes of components is usually related to the creation of additional notches and geometrical peculiarities. Multiple investigations have shown that a clear correlation between the local weld geometry and the fatigue life of welded joints exist. Thereby, the local increase of the local stress can be expressed by a stress concentration factor at the transition from the base material to the filler material, the so-called weld toe. The stress concentration factor can be de...
5 CitationsSource
Abstract The material properties of the heat affected zone (HAZ) in welds can significantly differ from the material properties of the base material (BM) due to recrystallization effects during hea...
1 CitationsSource
#1Clément Ernould (Fraunhofer Society)H-Index: 1
#2Jan Schubnell (Fraunhofer Society)H-Index: 3
Last. Michael StoschkaH-Index: 9
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The weld seam is generally the weak point of welded mechanical parts subject to fatigue loading. For this issue, a post-weld mechanical surface process called high-frequency mechanical impact (HFMI) was developed. This process combines both mechanical effects and a weld geometry improvement by generating compressive residual stresses and making a smoother transition between the base plate and the weld. Benefits of the process are statistically proven by numerous fatigue test results. Finite-elem...
1 CitationsSource
#1Jan Schubnell (Fraunhofer Society)H-Index: 3
#2Volker Hardenacke (Fraunhofer Society)H-Index: 6
Last. Majid Farajian (Fraunhofer Society)H-Index: 7
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After post-treatment with high frequency impact treatment (HFMI) of weld toes, a significant increase of fatigue strength or fatigue life can be achieved. Due to the lack of methods for the quantitative prediction of the HFMI benefits depending on the process and treated material, a widespread use of this process has not yet happened. One reason for that issue is that at the moment, no methods exist to predict the influence of the HFMI-treatment on welded components and structures at the moment ...
4 CitationsSource