The Simulation Of The Mechanical Excavator Working Resistance Based On Discrete Element Method

Mechanical mine excavators mining process is a complex physical process. Ore excavating resistance is one of the main design parameters of excavators, which is directly related to structural, mechanical strength, total weight of frame, power and transmission choices. The accurate extent of this indicator plays an important role in the design of excavator. At present, china’s mechanical mine excavators digging resistance calculation formula is still using the former soviet union raised in the 1950s.Soil types, tooth shape, blasting ore size are the main factors affecting digging resistance. The same soil sample, same bucket-shaped, different degrees of block blasting rock and mining 55m3 mechanical excavator has been used to study in this paper. This paper use discrete element theory, simulate by EDEM software, different degrees blocks of rock after blasting and weathering simplified as spherical discrete element. The particle has been judged as normal distribution after analyzing of the three groups particle size. Establishing stockpile model, bucket model and digging bucket trajectory mining process to get the curve of digging resistance in X, Y and Z direction. Maximum tangential, normal resistance and the time with mining thickness have been gotten by calculating.Analysis obtained that with the increasing block degree particle size, the maximum tangential digging resistance and maximum normal digging resistance are increased. The total angle of the arm and mining thickness trends are much the same when maximum digging resistance appears.When μ=0.3m, the distribution of the ore radius is mainly in (1.3-1.6) m. Discrete element method predicting the maximum tangential resistance error is 2.63%. The maximum normal resistance error is 2.14%. The lifting force error is 2.98%. The measuring thrust-pressure error is 3.48%.When μ=0.26m, the distribution of the ore radius is mainly in (1.0～1.3) m. Discrete element method predicting the maximum tangential resistance error is 13.98%. The maximum normal resistance error is 12.22%.The lifting force error is 9.53%. The measuring thrust-pressure error is 13.69%.These errors are within the acceptable range of projects, it can be seen that the discrete element method could be used as a research tool in study digging resistance in the mining process.