Modeling and validating the grabbing forces of hydraulic log grapples used in forest operations

Abstract

The grabbing forces of log grapples were modeled and analyzed mathematically under operating conditions when grabbing logs from compact log piles and from bunch-like log piles. The grabbing forces are closely related to the structural parameters of the grapple, the weight of the grapple, and the weight of the log grabbed. An operational model grapple was designed and tested to validate grabbing forces of the mathematical models while grabbing logs from five alternative diameter classes under two different working conditions. The working conditions and log sizes affected the grabbing forces significantly. Validation results suggest that the mathematical models developed can be used to estimate the grabbing forces required in the design process of log grapples. The results can be used by equipment manufacturers and researchers involved in the engineering design of grapples used in harvesting operations.

Citation

Wang, Jingxin; LeDoux, Chris B.; Wang, Lihai. 2003. Modeling and validating the grabbing forces of hydraulic log grapples used in forest operations. International Journal of Forest Engineering. 16(1): 77-85.