Gradeability of a Forwarder Based on Traction Performance

Based on the knowledge of the dimensional and mass features of a forwarder, a model was developed to assess its mobility during timber forwarding uphill in a safe and eco-efficient way. The model is based on knowledge of the position of the forwarder’s centre of gravity, its declared payload and the...

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Main Authors: Zoran Bumber, Andreja Đuka, Zdravko Pandur, Tomislav Poršinsky
Format: Article
Language:English
Published: MDPI AG 2023-01-01
Series:Forests
Subjects:
Online Access:https://www.mdpi.com/1999-4907/14/1/103
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author Zoran Bumber
Andreja Đuka
Zdravko Pandur
Tomislav Poršinsky
author_facet Zoran Bumber
Andreja Đuka
Zdravko Pandur
Tomislav Poršinsky
author_sort Zoran Bumber
collection DOAJ
description Based on the knowledge of the dimensional and mass features of a forwarder, a model was developed to assess its mobility during timber forwarding uphill in a safe and eco-efficient way. The model is based on knowledge of the position of the forwarder’s centre of gravity, its declared payload and the length of the loaded timber, as well as the gradeability for uphill timber forwarding based on the traction characteristics of the vehicle. The model connects two research approaches, (1) vehicle–terrain approach (distribution of axle loads depending on the longitudinal terrain slope) and (2) wheel–soil approach (estimation of the traction characteristics of the forwarder based on the wheel numeric), concerning previous research: (i) underload on the front axle of the vehicle, (ii) overload on the rear axle of the vehicle, (iii) permissible tire load, (iv) minimal soil bearing capacity, (v) wheel slip. Simulation modelling for the assessment of the forwarders’ mobility range during timber forwarding uphill was conducted on an example of an eight-wheel Komatsu 875 forwarder, with a declared payload of 16,000 kg, equipped with 710/45-26.5 tires, for which the position of the centre of gravity was determined by the method of lifting the axle. The results of the distribution of the adhesion load on the front and rear axles of the forwarder indicated that, during timber forwarding of 16,000 kg and 4.82 m long hardwood logs on a terrain slope below 68%, there is no critical unloading on the front bogie axle, nor overloading on the rear bogie axle, i.e., wheel tire overload that could limit forwarder mobility. For the specified range of longitudinal terrain slope, a minimal cone index of 950 kPa for an exemplary forwarder is an environmental factor and was calculated based on the nominal ground pressure of the reference (heavier loaded) rear wheels of the vehicle. The forwarders’ mobility range was determined by the intersection curves of the gradeability (based on forwarders’ traction characteristics at wheel slip of 25% vs. cone index) and the curve of the minimal soil cone index.
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spelling doaj.art-6c6cb47e95ce4423895f59eb6163f24e2023-11-30T22:17:47ZengMDPI AGForests1999-49072023-01-0114110310.3390/f14010103Gradeability of a Forwarder Based on Traction PerformanceZoran Bumber0Andreja Đuka1Zdravko Pandur2Tomislav Poršinsky3Croatian Forests Ltd., Forest Administration Zagreb, 10000 Zagreb, CroatiaDepartment of Forest Engineering, Faculty of Forestry and Wood Technology, University of Zagreb, 10000 Zagreb, CroatiaDepartment of Forest Engineering, Faculty of Forestry and Wood Technology, University of Zagreb, 10000 Zagreb, CroatiaDepartment of Forest Engineering, Faculty of Forestry and Wood Technology, University of Zagreb, 10000 Zagreb, CroatiaBased on the knowledge of the dimensional and mass features of a forwarder, a model was developed to assess its mobility during timber forwarding uphill in a safe and eco-efficient way. The model is based on knowledge of the position of the forwarder’s centre of gravity, its declared payload and the length of the loaded timber, as well as the gradeability for uphill timber forwarding based on the traction characteristics of the vehicle. The model connects two research approaches, (1) vehicle–terrain approach (distribution of axle loads depending on the longitudinal terrain slope) and (2) wheel–soil approach (estimation of the traction characteristics of the forwarder based on the wheel numeric), concerning previous research: (i) underload on the front axle of the vehicle, (ii) overload on the rear axle of the vehicle, (iii) permissible tire load, (iv) minimal soil bearing capacity, (v) wheel slip. Simulation modelling for the assessment of the forwarders’ mobility range during timber forwarding uphill was conducted on an example of an eight-wheel Komatsu 875 forwarder, with a declared payload of 16,000 kg, equipped with 710/45-26.5 tires, for which the position of the centre of gravity was determined by the method of lifting the axle. The results of the distribution of the adhesion load on the front and rear axles of the forwarder indicated that, during timber forwarding of 16,000 kg and 4.82 m long hardwood logs on a terrain slope below 68%, there is no critical unloading on the front bogie axle, nor overloading on the rear bogie axle, i.e., wheel tire overload that could limit forwarder mobility. For the specified range of longitudinal terrain slope, a minimal cone index of 950 kPa for an exemplary forwarder is an environmental factor and was calculated based on the nominal ground pressure of the reference (heavier loaded) rear wheels of the vehicle. The forwarders’ mobility range was determined by the intersection curves of the gradeability (based on forwarders’ traction characteristics at wheel slip of 25% vs. cone index) and the curve of the minimal soil cone index.https://www.mdpi.com/1999-4907/14/1/103forwarders’ centre of gravitydeclared payloadaxle load distributionwheel numeric
spellingShingle Zoran Bumber
Andreja Đuka
Zdravko Pandur
Tomislav Poršinsky
Gradeability of a Forwarder Based on Traction Performance
Forests
forwarders’ centre of gravity
declared payload
axle load distribution
wheel numeric
title Gradeability of a Forwarder Based on Traction Performance
title_full Gradeability of a Forwarder Based on Traction Performance
title_fullStr Gradeability of a Forwarder Based on Traction Performance
title_full_unstemmed Gradeability of a Forwarder Based on Traction Performance
title_short Gradeability of a Forwarder Based on Traction Performance
title_sort gradeability of a forwarder based on traction performance
topic forwarders’ centre of gravity
declared payload
axle load distribution
wheel numeric
url https://www.mdpi.com/1999-4907/14/1/103
work_keys_str_mv AT zoranbumber gradeabilityofaforwarderbasedontractionperformance
AT andrejađuka gradeabilityofaforwarderbasedontractionperformance
AT zdravkopandur gradeabilityofaforwarderbasedontractionperformance
AT tomislavporsinsky gradeabilityofaforwarderbasedontractionperformance