Acoustic Emission Monitoring as a Non-invasive Tool to Assist the Conservator in the Reactivation and Maintenance of Historical Vehicle Engines

Historical cars are an important part of the cultural heritage of the last 150 years. Their preservation in technical museums raises the question of how to preserve their primary functionality, namely their mobility. This implies being able to reactivate and to maintain their thermal engines, which are the source of their motion. However, the diversity and complexity of these engines generally require the presence of highly qualified personnel as well as detailed condition reports to assist the conservators. This study proposes to use acoustic emission techniques to facilitate these conservation procedures by objectifying the evaluation of the state of the engines and by providing systematic quantitative indicators for their health monitoring. To illustrate the implementation and the potentialities of this approach, different tests have been carried out at the National Automobile Museum of Mulhouse, on a Renault Type AG1. A dedicated experimental setup and the associated measurement protocol are presented in this paper. The derived results show the ability of this method to detect specific types of engine malfunctions, both during bench test and in situ measurement conditions. A critical discussion is finally proposed to highlight the feasibility and the possibilities of such laboratory techniques in the context of conservation assistance.