Beitrag zur Optimierung von Zerkleinerungs- und Verschleißprozessen in der Holzaufbereitungstechnik

Translated title of the contribution: A contribution to the optimization of comminution and wear processes in the wood processing technology

Philip Pichler

Research output: ThesisDoctoral Thesis


Chipping drums in wood processing machines are exposed to high cyclic operating loads and harsh environmental conditions. An essential aim is to treat the wood as economically and efficiently as possible in order to increase throughput and reduce energy consumption. This work provides an essential contribution to the optimization of the underlying comminution process. A novel measuring method for determining the local loads on a highly dynamic chipping drum is being developed. Validation experiments in the laboratory made it possible to create cutting force models and load collectives for different wood species. Furthermore, a hypothesis shows how blunt blades change the acting force direction on the tool. This explains why the intake behaviour changes with increasing blade wear. Model-based cutting force measurements serve as a basis for characterizing the influence of wet wood, but they have also been utilized to generate a numerical material model for finite element method simulation. Another point in this work addressed the study of wear resistant hard coatings which are subject to high abrasiveness. It has been shown that under the developed friction wheel test with rubber disc damage-equivalent wear phenomena are generated, which can be seen on components in the wood processing industry. In addition, models for wear mechanisms were described. The inclusion of hard, fine particles such as tungsten carbide shows 75% less material loss compared to conventional hard coatings. The fatigue strength is tended to be reduced by applied hard coatings; compared to mild steel a reduction of the fatigue strength up to 46% is recognizable. If also coarse hard particles are added, the fatigue strength is reduced up to 78%. In the future, the gained knowledge of this work will enable the targeted optimization of chipping drums in terms of durability at an early stage of development. The knowledge of the changing force direction can be used to detect worn tools early and to promote the improvement of security measures which protect the drum of impurities. Furthermore, by targeted use of numerical methods, the material flow within the chipper drum can be visualized and the structures can be optimized during the early development stage. The high potential of interspersed coarse tungsten particles in hard coatings in regard to wear resistance is shown, but a compromise should be found in terms of particle density distribution to minimize abrasive wear without significantly reducing the fatigue strength.
Translated title of the contributionA contribution to the optimization of comminution and wear processes in the wood processing technology
Original languageGerman
Awarding Institution
  • Montanuniversität
  • Grün, Florian, Assessor A (internal)
  • Hick, Hannes, Assessor B (external), External person
  • Leitner, Martin, Co-Supervisor (internal)
Publication statusPublished - 2018

Bibliographical note

embargoed until 16-02-2023


  • wood processing
  • cutting forces
  • tribology
  • abrasive wear

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