Often these machines are operated in harsh conditions such as in swamps or on steep slopes. Both static and dynamic simulations will be performed using this model to predict the gradability, slope stability and tractive effort of the feller buncher under a wide variety of operating conditions. STS feller bunchers are typically operated in densely forested areas, where there is a high likelihood of an accidental collision occurring between the machine boom and a standing tree. The computer model will be used to evaluate the design signficance of such an impact. The final model will be used to aid in the design of new feller bunchers that are both safer to operate and more effective in many different forest environments.
Skidders differ in their form, size, and application from agricultural tractors.
They have to work on various terrains including steep slopes and swampy ground. The grapple is used to grasp the logs during skidding. A track-type grapple skidder is being dynamically modeled in this research so that designers may modify the machine in the computer to find out the effects this will have on machine operation in the forest. Modeling of the skidder will be used to analyze it's drawbar pull and stability with various log weights and soil types on steep slopes. This dynamic simulation can predict machine behaviors such as engine performance, rpm, overturns, turning radius, and pulling capacity.