APPROXIMATE INTEGRATION FOR DETERMINING THE SURFACE ROUGHNESS

Measurement of surface irregularities, forming in aggregate its relief, belongs to linear-angular measurements. Their main feature is the smallness of the measured values. Measurements at production are subject to values: the heights of inequalities of 0.025 μm and steps – starting from 2 μm. A quantitative approach in analysis allows us to identify the optimal surface structure, which most closely meets the conditions of service material. It is worth noting that it is roughness, which has the strongest impact on the performance of engines of machines, as well as parts and components of various equipment. In case of roughness, as a rule, the parameter of the arithmetic mean deviation of the profile is used. Consideration of the mathematical aspects of data processing profilograms aimed at increasing the adequacy of the results. In the work the well-known formulas for determining the roughness of the surface of metals and alloys are analyzed, additional criteria for estimating microgeometry of surfaces are determined based on the methods of approximate integration, and the proposed correction of the formula for determining the mean arithmetic deviation of the investigated profile is determined. It is proposed to use the corrected formula, using the form factor k for practical calculations , where – amplitude values of deviations from the middle line of the profilogram, = 0,5 ... 0,67 – is chosen depending on the predominant form of the protrusions and depressions on the profilogram (triangles or curvilinear trapezes). The facts confirming the correctness of the correction of the calculation formula using are the relation between and . The process of determining the roughness of parts surfaces in the analysis of work profilograms based on the use of approximate integration, the application of the coefficient of form for projections and concaves on the profilogram in the formula for increasing the adequacy of determining the surface roughness by values and in a range of nominal values is investigated.