Verification of a modal transmission model to predict NVH parameters

Manufacturers and buyers of modern vehicles are paying increasing attention to vibroacoustic performance as the main indicator of comfort. Noise and vibration are undesirable phenomena and lead to energy losses and a decline in service life, and their reduction is achieved by using modern methods for optimizing NVH parameters of transmissions. An integral part of the implementation of this methodology and, at the same time, the goal of the proposed work is to create a verified modal model of a promising automatic transmission (AT). This modal model of automatic transmission should adequately describe its vibroacoustic behavior during operation. The paper presents the results of the calculated and experimental modal analysis, both of individual parts of AT and assembly of AT. During the experimental study, the LMS Scadas Mobile SCM05 hardware-software complex with Simcenter Testlab software in the Impact Testing software application was used. The experimental study results were processed in the Simcenter Testlab Modal Analysis software using the PolyMAX method. The analytical study was carried out using the Simcenter 3D software product with the Real Engenvalues solver and the subsequent transformation of the obtained results for verification. Verification was carried out by assessing the degree of convergence of modal characteristics using a modal assurance criterion (MAC). The novelty of the research lies in the development of a verified modal model of a promising AT, which allows optimization of NVH parameters at the early stages of design. In accordance with the purpose of the work, a verified modal model of a promising AT was created. As a result of the computational and experimental studies, modal characteristics of individual structural elements and AT were obtained. The results of the study made it possible to clarify a set of methods and approaches for carrying out studies of modal characteristics, which can later be used in the design of transport vehicles.