A Method For Estimating The Wear Of The Disc Cutter Based On Contact Mechanics

The cost of the disc cutter replacement due to wear accounts for about 1/3 of the entire tunneling cost. So the wear of the disc cutter is a crucial issue to be solved. However, to date, the methods for quantitative calculating the wear of the disc cutter are still defective. In this paper the wear of the disc cutter is studied, and a method for estimating the wear of the disc cutter based on contact mechanics is proposed. This method provides a basis for estimating the life of the disc cutter, determining the replacing time of the disc cutter and extending the life of the disc cutter.The specific contents of this paper include:1) According to the friction theory, the wear rate is introduced. This paper argues the wear of the disc cutter is mainly due to slip wear, the abrasive volume of the disc cutter and the friction power is proportional,the ratio coefficient is wear rate.2) The slip ratio is introduced to calculate the friction power. According to the slip theory of rolling object under the effect traction from contact mechanics, the slip ratio and the slip speed are expressed. Then according to the relationships between the slip distance, friction force and the friction power, the friction power is expressed.3) According to the geometry of the disc cutter, the abrasive volume is expressed by structural parameters. It can be seen from the expression, the abrasive volume is the function of the radial wear.4) According to the relationship between the abrasive volume of the disc cutter and the friction power, an equation is proposed, in which the boring parameters、the structural parameters and the geological parameters are known, the radial wear is unknown. So the radial wear can be obtain by solve the equation.5) Establish the finite element contact model between the disc cutter and the rock by ANSYS. The slip situation of the disc cutter under the static force is analyzed by suing this model. The results obtained by Numerical and theoretical calculation are compared, in order to verify the correctness of theoretical calculation.Through analyzing example, the conclusions include:1) When the penetration depth is unchanged, with the boring distance Increasing, the value of the incremental radio wear decreases and is basically unchanged. With the boring distance increasing, the radial wear is also increased. The radial wear and the boring distance have linear relationship after the disc cutter edge is worn. The boring distance is an important factor on the wear of the disc cutter.2) When boring same distance, with the penetration depth increasing, the incremental radio wear is increased, the radio wear is also increased. The penetration depth is also an important factor on the wear of the disc cutter.3) Compare the incremental radio wear and the radio wear obtained by two estimation formulas; we can see the force is also an important factor on the wear of the disc cutter. With the force increasing, the wear is also increased.