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冲击凿入效率(施于岩石破碎的能量对冲击能量之比)是评价和设计冲击凿入系统的重要参量.本文运用一维应力波理论导出了任意入射应力波形的凿入函数;对任一给定的单圆柱和双圆柱活塞-长杆硬岩凿入系统,其各阶凿深系数(u~*k)可示为波形向量(ψ_k)的线性变换;由矩阵或递推公式表达为: (u~*_k)=(α_(kp))(ψ_k)或u~*_k=u~*_k-1~(e-λ+ψ_k)则凿入效率: η=4θ(1-e~(-λ))~2(maxu~*_k)~2式中(α_(kp))——系统特性方阵; (λ,θ)——系统常数. 用电子计算机计算了活塞柄头长度比j=(4,5)(工程常用值)两种情况下具有不同断面特性的双圆柱活塞的凿入效率(单圆柱活塞可视为双圆柱活塞的特例). 对任意确定的入射应力波形,都可用足够小周期△t的阶梯函数来逼近,所以这个方法可以推广到任意入射应力波形凿入效率的计算.
Impact chipping efficiency (applied to rock crushing energy to impact energy ratio) is an important parameter to evaluate and design impact chipping system.In this paper, one-dimensional stress wave theory is used to derive the capping function of any incident stress waveform. Given a single-cylinder and double-cylinder piston-longwall hard rock chisel system, the chisel depth factor (u ~ * k) of each step can be expressed as a linear transformation of the waveform vector (ψ_k); expressed by a matrix or recursion formula : (u ~ * _k) = (α_ (kp)) (ψ_k) or u ~ * _k = u ~ * _k -1 ~ (e-λ + ψ_k) (- λ)) ~ 2 (maxu ~ * _k) ~ 2 where α_ (kp) - the square of the system characteristic; (λ, θ) - the constant of the system. j = (4, 5) (engineering common value) The cutting efficiency of double-cylinder pistons with different cross-sectional characteristics in both cases (single-cylinder piston can be considered as a special case of double-cylinder piston.) For any given incident stress waveform, Can be approximated by a staircase function with a small enough period Δt, so this method can be generalized to the calculation of the efficiency of any incident stress waveform.