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Licensed Unlicensed Requires Authentication Published by De Gruyter August 10, 2018

An experimental study of the chipping process with focus on energy consumption and chipping angles

Jonas L. Nyström, Per A. Gradin and Benny Thörnberg


A series of chipping experiments were performed under both dynamic and quasi-static conditions in a laboratory wood chipper (dynamic) and in a MTS-servohydraulic testing machine (quasi-static). One aim with the experiments was to investigate the rate dependency of the energy consumption during chipping. Another aim was to try to determine the load per unit knife edge length required to initiate cutting. The experiments were carried out using different combinations of spout and edge angles. It was found that for large edge angles (keeping the spout angle constant at 30°) there was a slight rate dependency such that the energy consumption was larger at higher cutting rates which is quite in opposite of what is expected if wood is assumed to be a viscoelastic material. It was also found that to determine the force at initiation of cutting, is not a trivial task. Both Acoustic Emission monitoring and visual inspection was used to this end. The wood species used in this study was pine (Pinus silvestris).


Staffan Nyström at Mid Sweden University’s mechanical testing laboratory is greatly acknowledged for performing the chipping trials.

  1. Conflict of interest: There are no conflicts of interest.


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Received: 2018-04-05
Accepted: 2018-06-27
Published Online: 2018-08-10
Published in Print: 2018-09-25

© 2018 Walter de Gruyter GmbH, Berlin/Boston

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