This paper presents the effects of modeling the stress in the burnished layer of a complex spatial surface that was previously milled. A spatial kinematic-geometric model of the surface structure after milling is used. This paper presents the results of a numerical experiment on the synergic influence of the technological milling and burnishing parameters responsible for the final state of the geometric structure of a surface on the post-machining stress in the surface layer. The stress in the surface layer plays an important role because it is frequently responsible for the development of cracks, corrosion, and cavitation (in the surface area of injection aluminum molds, press tools, and core cutters). A proper understanding of the mechanisms responsible for the origin and development of residual stress will be conducive to the improvement of functional properties and longer tool life.

During measurements, the crankshafts of marine engines are usually supported on a set of rigid prisms. Such prisms maintain a constant height position, cause different values of reaction forces and, consequently, may cause elastic deformations of the crankshafts. Thus, the measurements of the dimensions and geometry of the crankshaft may be distorted. This article proposes a measuring system developed to support the crankshaft with a set of flexible supports. These supports implemented the given reaction forces, which ensured the elimination of the crankshaft deformations, regardless of the possible deviations, i.e., in the coaxiality of the main crankshaft journals. The values of these forces were calculated using the finite element method (FEM). These calculations showed that in order to eliminate the crankshaft deformations, the values of the reaction forces must change not only on individual supports, but also with the change of the shaft rotation angle during the measurement. The numerical experiments showed that the application of flexible supports results in uniform contact reaction forces on adjacent main journal supports. This uniformity occurs regardless of the quality of the crankshaft geometry. Thus, the necessity to use a set of flexible supports for measuring marine engine crankshafts was confirmed. The research also showed that the values of the reaction forces ensuring the elimination of shaft deflections under the assumption of nodal support can be treated as corresponding to the resultant reaction forces realized by the prismatic heads.

Large crankshafts are highly susceptible to flexural deformation that causes them to undergo elastic deformation as they revolve, resulting in incorrect geometric measurements. Additional structural elements (counterweights) are used to stabilize the forces at the supports that fix the shaft during measurements. This article describes the use of temporary counterweights during measurements and presents the specifications of the measurement system and method. The effect of the proposed solution on the elastic deflection of a shaft was simulated with FEA, which showed that the solution provides constant reaction forces and ensures nearly zero deflection at the supported main journals of a shaft during its rotation (during its geometry measurement). The article also presents an example of a design solution for a single counterweight.