Modelling the process of splitting wood and chipless cutting Pinus sylvestris L. wood in terms of designing the geometry of the tools and the driving force of the machine

Abstract

The size of wood is reduced by splitting or chipless cutting whilst logging trees, limbing, or preparing wood to be a fuel, for example, or in order to improve the efficiency of wood drying processes. Low costs of wood processing are desirable in each of these processes. The article presents experimental and simulation tests run in ABAQUS software, which allow for an analysis of the geometry of cutting tools used during the splitting or chipless cutting of wood in order to determine the cutting force and driving force of the machine executing such a process. The tests involved wood of Pinus sylvestris L. (moisture content: 8.74% ± 0.1%) in four configurations (chipless cutting transverse to the fibres (90°–90°), splitting along the fibres (0°–90°), splitting radially to the grain (90°–0°) and splitting tangentially to the grain (90°–0°)). Analysis of the force and strength of the blade proved that an effective tip angle of the knife blade falls between 30° and 45°. The presented results also suggested that splitting wood along the fibres (0°–90°) is preferable in a machine process, while splitting tangentially and radially to the wood grain (90°–0°) is preferable when splitting wood using manual tools.

Wood Chipper Design for Biofuel Production in a Global Catastrophic Loss of Infrastructure Scenario

“…The direction of the cutting blade relative to the grain of the wood has a significant impact on cutting force-in some cases, up to 300% [45]. Wood is weaker cutting along its fiber direction or with the grain, such as splitting wood with an ax, than compared to cross-cutting, such as sawing orthogonally [46].…”

“…Testing various sizes of branches, Hatton et al were able to quantify a relationship between cutting force and branch area [51]. Warguła et al found that thinner blades used less energy but required more frequent repair; although the relationship between repair cost and energy was not quantified, a 10 mm blade and 30 degree cutting angle were recommended [45].…”