the occurrence of chatter vibrations in boring operation has a great influence in improving workpiece dimensional accuracy, surface quality and production efficiency. in this paper instability analysis of machining process is presented by dynamic model of boring machine. this model, which consists of machine tool’s structure, is provided by finite element method and ansys software. the model is...

Boring is a frequently employed finishing operation in machine shops. Boring is a process in which pre-drilled holes or holes in cast, forged or extruded components are enlarged or finished with a cutting tool mounted on a boring bar. The process is mostly used in applications where close dimensional tolerances and good surface finish are required. In this research work based on the theoretical...

greater levels of complexity in tunnelling with tunnel boring machine (tbm) allow higher chances of failures that may increase the potential hazardous risks. this paper presents the results of a study on tbm reliability using risk analysis. machinery failure mode and effect analysis was applied to analyze the risks of a tbm using qs9000 and sae.j1739 recommendations. for this purpose, 48 failur...

earth pressure balance tunnel boring machines (epb-tbms) are favorably applied in urban tunneling projects. despite their numerous advantages, considerable delays and high maintenance cost are the main disadvantages these machines suffer from. reliability, availability, and maintainability (ram) analysis is a practical technique that uses failure and repair dataset obtained over a reasonable ti...

clogging occurs during mechanical tunneling with a tunnel boring machine (tbm) because of adhesion of clayey soils to the cutterhead and conveyor system. the present study examined the effects of water and sand contents on clogging in montmorillonite clayeysoil. testing was carried out using an adhesion test device on 28 samples with different water and sand contents to determine adhesionstress...

1. SOLID MODEL The main aim of the 3D design is to obtain a system that is very close to the real model considering the imposed functional conditions. In the machine tool design the parts are calculated for a proper strength and the stress level in each part is imposed to do not exceed material accepted values. A machine tool, particularly one that is used for drilling and boring processes (Fig...

For rotating-tool machining, such as milling, line boring, and cylinder boring, the tool rotation causes the machining force on each tooth to rotate repetitively relative to the inertial coordinate frame. This is quite different than stationary-tool machining, such as turning or boring with a stationary boring bar, in which the force directions are fixed relative to the inertial frame. Although...

The theoretical research objectiveis to create prerequisites for the development of new designs boring tools. task which paper is devoted: identification constructive varieties tools; improvement geometric shape conical part tool. Research methods: modeling elastic deformations various novelty work: a design with transitional section from prismatic in form cone and barrel-like proposed introduc...