Cutting process in grinding is transitional and the transitional regions which precede the cutting region affect significantly grinding results. Therefore in order to understand and improve grinding process, the grinding process should be analyzed after making clear the interaction between cutting edge and workpiece from a point of view of the transitional cutting. From the above mentioned point of view, in the 1st Report the surface formation curve, which is fundamental to make clear the interaction between cutting edge and workpiece, has been determined.
In this report, grinding results such as grinding force, work hardened layer and surface roughness will theoretically be analyzed based on various information from the analysis of the transition cutting process and the surface formation curve, and then effects of working conditions such as velocity ratio, successive cutting edge spacing and spring constant of grain mounting on grinding results will be discussed.

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In this paper, the stresses acted upon the tool edge surtace in the rubbing-cutting transient are analized by the photo-etastic experimental method, in which the lead plates are cut with roundish tool of epoxy resin, and the material flow along that surface is discussed. And, in order to investigate the effects of cutting fluid at the beginning of cut, it is not only to carry out by dry cutting but by wet cutting when using colza oil, carbon tetrachloric or polyflon (D-1) as cutting fluid. The main results are as follows.
At a point of the tool-pilled up material interface, the tangential stress τ is zero and the normal stress σ takes the maximum value. The sign of τ differs at the right and left of this point, and the material flow away to the each other side. Now, it may sately to say that is the separating point. According to the addition of tool-material contact length followed by the tool advance, σ and τ gradually increase and the separating point travels toward the rake surface side. Moreover, about these stress distributions and the position of separating point, there are varied with kind of cutting fluids. Cansequently, it is able to estimate the effects of cutting fluid.

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This paper describes some analyses and experiments about surface roughness generated by rolling tool. The results obtained are as follows. When the tool point is not located on the rolling center, surface roughness depends on n/N (n : number of tool rolling, N : number of work rotation). At n/N= i (i = 0, 1, 2, …) surface roughness becomes minimum, and at n/N= i+ 0.5 it becomes maximum, while except the case of n/N=i, i+ 0.5, waviness is generated generally. But when the tool point is just on the rolling center, surface roughness is not affected by rolling.

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It is intended to verify how a fused state of the worn surface, called the secondary zone, is formed on the wear-land of alundum wheel and also how it changes in the grinding process. In this experiments, high carbon tool steel is ground with alundum wheel under two grinding speeds, and the observation is performed not on replica but on the worn surface with metallurgical microscope. And then the forming conditions of the nuclei that grew into the secondary zone are considered. The results are as follows :
(1) When a wheel is used at the speed of 2000 m/min, nuclei appear at the trailing edge of the wear-land while with decreasing of the speed the appearing position graduary travels toward the central portion. And at 1160 m/min a closed type of the secondary zone is formed.
(2) If the secondary zone is formed on a cutting edge with conparatively large length of the wear-land, it spreads rapidly to the other cutting edges lying the same grinding direction with smaller length of the wear-lands.

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In the previous paper, a statistical approach for determining the undeformed chip length in grinding was described. In this paper the probability density function for the following factors are succesively obtained under the assumption that conical grain tips distribute three-dimensionally at random in a grinding wheel :
(1) grain depth of cut, grain cutting breadth and grain cutting area on any cross sectional plane of work,
(2) the maximum grain depth of cut.
Abreast of theoretical analysis, the Monte Carlo simulations of the grinding process are carried out in two ways, one is on a cross section perpendicular to grinding direction and the other in a three dimensional space. Those results show good agreement with theoretical analysis.

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A phenomenon in the beginning of cutting is classified rubbing region and ploughing region. In the rubbing region the deformation of bulk is elastic though tips of surface asperities are deformed plastically. It is obtained that the phenomenon is influenced by many foctors, especially by the tool-edge roundness.
In this study, in order to find the factors influencing the beginning phenomenon of cutting, an experiment was carried out on low speed orthogonal-cutting with a gradual increasing depth of cut.
As the results, there is a critical normal force which has a linear relation to the tool-edge roundness at the stage when the rubbing phenomenon changes into ploughing phenomenon, and the rubbing phenomenon is influenced by the machined surface layer of workpiece. Then, from the distribution of shear-stress, it is suggested that the transition to ploughing occures because the yielding of work-material developes in neighbourhood of the boundary region (the bulk and the surface layer).

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This paper describes some experimental results with the influence of grinding stiffness, stiffness of grinding wheel and mechanical system on the grinding process as well as their characteristics. These results are summarized as follows.
(1) The strongest correlation is observed between the grinding stiffness and the attritions wear (cutting edge ratio) of grinding wheel. Namely the grinding stiffness shows a rapid increase when the magnitude of cutting edge ratio reaches an almost constant value.
(2) The stiffness of grinding wheel is considerably large as compared with the grinding stiffness or stiffness of mechanical system, then it can be considered that the elastic deformation of grinding wheel is negligible.
(3) The actual depth of cut is affected remarkably by the stiffness of mechanical system.

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In order to facilitate ways to estimate the structural dynamics of machine tools in the design stage, and also to provide a theory for designing dynamically optimum machine tools which would have minimum chance of machining chatter, a computer program was developed which could calculate the dynamics of three-dimensional structures. The present simulation technique does not rely on the conventional lumped-parameter model which assumes that the structure is composed of lumped masses, springs and dampers, but calculates the harmonic response of elastic structures and its mode shapes based on the data as they appear on the design drawings. Since the machine tool structures are three-dimension, it is possible to enlighten their dynamics only by analyzing them as composite three-dimensional systems. This first report describes the approach of the computer program and discusses the results of simulations on some simple models. The accuracy of the computer program is demonstrated by comparing the computed and experimental results of harmonic response of a particular model.

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