Deep hole drilling methods are used for drilling holes with a high length-to-diameter ratio, good surface finish and straightness. Due to the slender tool-boring bar combination needed for producing holes with a high length-to-diameter ratio, the process is susceptible to dynamic disturbances. These disturbances can be classified as chatter vibration or spiralling. The work presented in this pa...

Due to the lower tool as the research object to analyze the vibration of the drill string, causes the loss of the low order natural frequency of the drill string and the inherent vibration mode, give rise to the distortion and error of the result from the transient analysis of the drill string. For this purpose, the whole drill string of the deep wells is studied in the article, build the mecha...

To assess whether zona drilling with a 1,480-nm laser induces heat shock in eight-cell embryos, we measured hsp70i RNA levels in sets of single blastomeres isolated after laser treatment of mouse embryos that had or had not been heated at 43 degrees C. Unlike heating, laser zona drilling did not stimulate hsp70i expression, even in the blastomeres closest to the laser beam, corroborating the sa...

In automated manufacturing systems such as flexible manufacturing systems (FMSs), one of the most important issues is the detection of tool wear during the cutting process. This paper presents a hybrid learning method to map the relationship between the features of cutting vibration and the tool wear condition. The experimental results show that it can be used effectively to monitor the tool we...

Many vibration-exposed workers have been found to suffer from muscle fatigue and decreased grip strength. Therefore in order to quantify and determine safe levels of human exposure to vibration, measurements and analysis of significance vibration factors are necessary. There are three main objectives in this study. The first one is to investigate the characteristics of vibration factors (vibrat...

Resonant Sonic Head drilling (RSHD) induces axial vibrations along the drillstring system which affect the accuracy and quality of pre-reinforcement required to tunnels excavation in complex soils. The main goal of this paper is to control these vibrations in order to improve this process. First, an infinite dimensional equations as vibration model are elaborated with Neumann boundary condition...

A modified model for predicting the friction force between drill-string and borehole wall under in-plane vibrations was developed. It was found that the frictional coefficient in sliding direction decreased significantly after applying in-plane vibration on the bottom specimen. The friction reduction is due to the direction change of friction force, elastic deformation of surface asperities and...

Ultrasonic vibration-assisted rock breaking is a potentially effective technique to accelerate hard drilling processes. Fatigue damage primary factor that governs fragmentation subject ultrasonic vibration, and when such accumulates critical level via crack initiation propagation, macro-damage (e.g., macro-cracks) will occur. To date, however, the specific fatigue mechanism of materials under h...

Emily Stone Department of Mathematical Sciences, The University of Montana, Missoula, MT 59812 U.S.A. Abstract In this paper we present stability analysis of a nonlinear model for chatter vibration in a drilling operation. The results build our previous work [1, 2], where the model was developed and the nonlinear stability of the vibration modes as cutting width is varied was presented. Here we...