## 2 Part Type, Machine-Made Parts and Experimental Characterizations
For the parts with numbers 13 to 24, uniform distribution was used, for which more extreme values are more likely. For better handling, the nominal values were rounded to integer multiples of 0.05 mm. In addition, for some parts (no. 8 to 12 and no. 20 to 24), a single dimension was manually manipulated in each case. This should achieve a geometric value outside the usually expected interval of three times the scatter value from the mean value. According to the geometric specifications, all parts were machined from a single batch of rolled 6082 aluminum alloy (which is also commonly referred to as material no. 3.2315, AlSi1 MgMn or AlMgSi1) using a consistent production strategy to reflect a reproducible series process. In addition, various cuboidal material samples were cut out of the raw material. They were produced for material property investigations. After manufacturing, the parts were characterized with multiple methods. Hereby, two aspects were considered for quantitative information such as actual geometry, material characteristics, and eigenfrequencies. Temperature was recorded consistently, whereby values between 19.5\({}^{\circ}\)C and 25\({}^{\circ}\)C were observed. With the help of a linear model and suitable temperature coefficients based on literature or experiments, temperature effects were eliminated or derived characteristics were corrected to a temperature of 20 \({}^{\circ}\)C. Regarding measured eigenfrequencies, for example, sample temperatures between 19.5\({}^{\circ}\)C and 22 \({}^{\circ}\)C were registered indirectly via air temperature. Former experiments with the help of a climatic chamber showed a frequency decrease in the magnitude of a quarter per thousand due to a temperature increase of 1 K for the real connecting rods. Single outliers were also identified and eliminated with a proper rule. Both of these aspects regarding temperature and outliers should ensure a high data quality and minimize perturbation effects as far as possible. The machine-made connecting rods were measured geometrically in order to precisely identify the actual dimensions, which inevitably differ from the specified nominal geometry. For this, a coordinate measuring machine was used. Only the edge radii were analyzed manually via a radius gauge. The measured data were finally applied to three geometric models with increasing level of complexity, that is, increasingly realistic models. The first model, which was mentioned before and is addressed as standard unless otherwise stated, uses 8 individually updated dimensions per part. It includes an averaged and identical value for both cylinder ring heights and a nominal value of 3 mm for the edge radii. The second model with 10 individually updated dimensions uses individual values for the two cylinder ring heights as well as measured edge radii. The third model, which has 17 individual geometric values per part, also takes into account additional geometric parameters with which deviations of the primitive geometry elements from perfect symmetry or idealized form can be represented. The surface quality of the manufactured parts was not measured quantitatively. However, a visual inspection using specular reflections showed that the surfaces are of high quality with minor machining marks corresponding to a milling fine machining with modern equipment. Density measurements were made at several material samples from different regions of the raw material following Archimedes' principle. A homogeneous density of slightly more than 2705 kg/m\({}^{3}\) was found with a negligible uncertainty in the range of only a few per thousand. Ultrasound time-of-flight measurements (longitudinal as well as transversal waves, 5 MHz each) using suitable samples indicated slightly anisotropic elastic properties for the rolled raw material. Nevertheless, mean isotropic properties were calculated from ultrasound data by averaging. As a result, values of approximately 71.58 GPa and 26.58 GPa were found for [PERSON]'s modulus and shear modulus.