Design of a turboshaft engine mounting bracket with static and modal analysis

In this thesis study, the engine connection, which is the engine test system interface, has been structurally examined in order to work in a safe area in the test room where turboshaft engines are tested. Accuracy of the measurements to be collected in the test cell and safety of the engines subjected to the test is the first priority. Therefore, the robustness of the engine connection has critical importance. Also, test chamber components are examined in detail. Sub-systems such as dynamometer, air and fuel supply systems and data acquisition system are mentioned. In the thesis, static and modal analyses are performed on the engine connection interface. Mesh independence study is carried out by comparing different mesh structures. The Cartesian mesh structure and element size of 1.25 mm were found to have the lowest skewness metric and the highest element quality. According to the static analysis results, the maximum equivalent stress was calculated as 65.7 MPa and the maximum total deformation as 0.484 mm. It was verified that these values were not above the specified limits. In addition, with the parametric analysis study, the effect of the analyses performed by changing some thicknesses of the engine connection parts on the general behaviour of the system was evaluated. The first eight natural frequencies and mode shapes of the engine mount were determined by modal analysis and the dynamic behaviour of the system was investigated. Particular attention has been paid to ensure that the low frequency modes are far away from the frequencies coming from the gas turbine engine. The design regions with the possibility of resonance are emphasised. The results are obtained from the analyses have provided important information when evaluated in terms of creating more rigid engine connections and increasing the reliability of the test system. In conclusion, this thesis study aimed to evaluate the engine connection interfaces with the philosophy of structural analysis with finite elements in the design of turboshaft engine test chamber. The results of the analyses have both contributed to the literature and provided information for use in test field.