Statistical analysis of the lifetime of diamond impregnated tools for core drilling of concrete

Malevich, N.1, a; Müller, C.1, b; Kansteiner, M.2, c; Biermann, D.2, d; Ferreira, M.3, e; Tillmann, W.3, f

Lehrstuhl Statistik mit Anwendungen im Bereich der Ingenieurwissenschaften, Fakultät Statistik, TU Dortmund, 44221 Dortmund
Institut für Spanende Fertigung, Technische Universität Dortmund, Baroper Str. 303, 44227 Dortmund
Lehrstuhl für Werkstofftechnologie LWT, Technische Universität Dortmund, Leonhard-Euler-Str. 2, 44227 Dortmund

a); b); c); d); e); f)


The lifetime of diamond impregnated tools for core drilling of concrete is studied via the lifetimes of the single diamonds on the tool. Thereby, the number of visible and active diamonds on the tool surface is determined by microscopical inspections of the tool at given points in time. This leads to interval-censored lifetime data if only the diamonds visible at the beginning are considered. If also the lifetimes of diamonds appearing during the drilling process are included then the lifetimes are doubly interval-censored. A statistical method is presented to analyse the interval-censored data as well as the doubly interval-censored data. The method is applied to three series of experiments which differ in the size of the diamonds and the type of concrete. It turns out that the lifetimes of small diamonds used for drilling into conventional concrete is much shorter than the lifetimes when using large diamonds or high strength concrete.


Discussion paper SFB823 Nr.30/2018, (2018), doi: 10.17877/DE290R-19809