Computer aided design of machine tool bed structures

ABSTRACT COMPUTER AIDED DESIGN OF MACHINE TOOL BED STRUCTURES AKPOLAT, Abdullah Ph.D. in Mechanical Engineering Supervisor: Prof. Dr. İ. Hüseyin FİLİZ April 1997, 147pages in this thesis, a study on the design of machine tool bed structures by using the finite element method is presented. Bolted and welded joints are analysed. Emphasis is given to the analysis and design of slidevvays. Deformations and pressure distribution on the slidevvay surfaces are mainly considered. A thorough revievv on the stiffness of the members of bolted joints is presented. The effects of bolt diameter, grip length and thickness ratio on the stiffness of the members are investigated. A practical formula is suggested for the calculation of member stiffness. Fillet welded joints are analysed and stress distribution on welded regions in different directions are represented in graphical form. Analysis of machine tool slidevvays has been carried out by using two and three dimensional slidevvay models. Models are considered to consist of contact elements at the interface of sliding surfaces. Flat, combined (flat and vee) and dovetail type of slidevvays ara nıodelled. Pressure distributions and deformations are determined vvith the use of ANSYS Rev. 5.0A non-linear contact elements. Key VVords: Machine Tool Slidevvays, Contact Deformations, Stiffness, Pressure Distribution