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The continuous advancement in the field of automotive engineering supports the development of new working techniques regarding the definition of new machine parts. In this study, the topological optimization of a tangentially loaded brake caliper is treated. For the first part of the study, the distribution of forces inside the caliper is explained. In the next stage, the computation stage, the working method approached for topological optimization is described. The results and conclusions are commented in the last part of this paper.

Continuous progress in the automotive field involves the use of new working methods in the calculation and optimization of the internal combustion engine parts. On this occasion, in this paper, the impact of a topological optimization on the piston in the combustion engine of the conventional or hybrid electric car was studied. Starting from the simulation of the Otto cycle, the dimensional calculation is reached, after which a classical FEA analysis is carried out in order to establish the reference values. In the last part, the data of the classical analysis are compared with those of the topological analysis in order to perform a comparison of their results. The purpose of this study is to reduce the volume of the optimized part and to increase its rigidity.

The piston ring is one of the main elements in an internal combustion engine. Together with the cylinder sleeve, the piston ring has two basic functions: (1) contacting the cylinder sleeve to prevent the gases formed above the piston from migrating to the crankcase and (2) as a translation couple, formed of the piston-ring and cylinder-sleeve assembly. Complex tribological phenomena occur in the piston-ring and cylinder-sleeve tribosystem, according to variations in sliding speed, gas pressure, and temperature. This paper presents a method of calculation of the thickness of the lubricant film in the piston-ring and cylinder-sleeve tribosystem, using the Reynolds equation, integrated in specific conditions. According to the Newtonian behaviour of the lubricant, the shear stresses in the lubricant film between the piston ring and cylinder sleeve are determined. A computational procedure to determine flash temperatures in the piston-ring and cylinder-sleeve tribosystem is presented. The theoretical results, including film thickness, sliding speed, gas pressure, and flash temperatures for a complete crankshaft cycle are also presented.