Dynamics of the Grinding Wheel

The thesis commences with a review of the published work on high speed grinding and a description of the nature and structure of grinding wheels is detailed. The technique of metal removal during grinding is discussed and a number of photographs of the swarf produced during different stages of grinding are shown. A method of mounting electrical resistance strain gauges on grinding wheels is described together with the technique developed of cutting the grinding wheel to produce the test pieces required for the determination of the mechanical characteristics of the grinding wheel materials. The tests of mechanical characteristics and the results obtained are detailed. The equipment, instrumentation and procedure for measuring the dynamic strains in grinding wheels are specified together with the method of mounting the grinding wheels on the machine for the tests to be carried out. The method and results of determining the clamping force exerted by the flanges on the grinding wheel is explained. The results of the tests to determine the stresses, caused by centrifugal action, in grinding wheels clamped with different sizes of flanges are given, and the theoretical stress distribution in the grinding wheel is studied with the help of a computer program. The technique and the results of tests to determine the stresses, caused by centrifugal action, in a duralumin disc clamped by different size flanges and also in a non-clamped mode are given. The experimental results are compared with the theoretical results which indicates the advantages of clamping the grinding wheel. Between flanges and that the safety factor when using grinding wheels clamped by large flanges is greater than that generally assumed. The tests using the photo-elastic technique to determine the stress pattern in a wheel subject to two systems of forces are described. The effect of the internal shape of a guard on a grinding machine in retaining the sections of a grinding wheel which burst in use are examined. In the two appendixes the theory of electrical resistance strain gauges and photo-elasticity are detailed in some length