TY - THES

T1 - Optimization of a quick-release fastener for cutting discs in industrial mining applications

AU - Kernbichler, Christoph

N1 - embargoed until 07-12-2022

PY - 2017

Y1 - 2017

N2 - The availability of an underground mining machine forms the basis for the economic operation of each mining industry. Production downtime for maintenance- and repair activities have to be reduced to a minimum to reach given production-, respectively road development targets. This thesis represents the optimization process of a Disc Cutter tensioning system for the prototype of a new hard-rock miner, which was developed to lower the downtime during cutting disc replacement. The concept is based on a frictionally engaged cone connection consisting of shaft, fastener and cutting disc. Various kinds of finite element models (axisymmetric, 30°-, 180°-segment) are used to perform parametric studies, while varying the cone angle, the frictional ratios and the initial clearance between fastener and shaft. In these models, contact problems and the implementation of bolted joints in the FE analysis have to be dealt with. Therefore, the influence of different contact approaches, bolt models and simplifications are tested in view of their applicability in the FE models of the Disc Cutter tensioning system. The subsequent optimization process is divided into the three main application scenarios assembling, dismantling and the impact of external loads. The aim is to identify the influence of the different parameter configurations and to find a design that is able to transfer the cutting forces across the frictionally engaged cone connection without slipping and that, at the same time, keeps the stresses in the fastener in an acceptable range.

AB - The availability of an underground mining machine forms the basis for the economic operation of each mining industry. Production downtime for maintenance- and repair activities have to be reduced to a minimum to reach given production-, respectively road development targets. This thesis represents the optimization process of a Disc Cutter tensioning system for the prototype of a new hard-rock miner, which was developed to lower the downtime during cutting disc replacement. The concept is based on a frictionally engaged cone connection consisting of shaft, fastener and cutting disc. Various kinds of finite element models (axisymmetric, 30°-, 180°-segment) are used to perform parametric studies, while varying the cone angle, the frictional ratios and the initial clearance between fastener and shaft. In these models, contact problems and the implementation of bolted joints in the FE analysis have to be dealt with. Therefore, the influence of different contact approaches, bolt models and simplifications are tested in view of their applicability in the FE models of the Disc Cutter tensioning system. The subsequent optimization process is divided into the three main application scenarios assembling, dismantling and the impact of external loads. The aim is to identify the influence of the different parameter configurations and to find a design that is able to transfer the cutting forces across the frictionally engaged cone connection without slipping and that, at the same time, keeps the stresses in the fastener in an acceptable range.

KW - Schneiddisken

KW - Hinterschneidtechnik

KW - Kontaktsimulation

KW - Kegelspannsatz

KW - disc cutter

KW - cutting disc

KW - undercutting

KW - contact simulation

KW - frictionally engaged cone connection

M3 - Master's Thesis

ER -