Prévention de la charge de travail au-dessus de la tête - le cas assemblage/désassemblage des turbines à gaz

Abstract

In industrialized countries, workers often face musculoskeletal disorders (MSDs), which affect both their health and company productivity. To prevent these disorders, it is essential to identify the risks and factors contributing to their occurrence. The main objective of this thesis is to evaluate overhead work in the context of gas turbine assembly. A critical literature review was conducted to define this type of work and identify the parameters influencing its occurrence, to select the most appropriate ergonomic methods for evaluating the studied work system. The Siemens Tecnomatix Jack 7.1 software was used to design the workstation. Time calculations were performed using the predetermined time tool based on the Methods-Time Measurement-1 (MTM-1) method of Jack 7.1, and rest time was calculated according to the guidelines of the International Labour Organization. A virtual environment was created using a digital mannequin in Jack 7.1, and representative postures of real assembly situations were ergonomically analyzed using the Rapid Upper Limb Assessment (RULA) method integrated into Jack 7.1. The Occupational Repetitive Actions Index (OCRA Index) and Key Indicator Method For Manual Handling Operations (KIM-MHO) methods complemented the analysis, providing a more detailed assessment of ergonomic risks. For the study of hand movements, alternative methods were employed, including the use of the VMG 30 / VMG30+ Technical Datasheet (Virtual Motion Glove) data glove and the combination of VMG 30 with AnyBody Modeling System software. A qualitative evaluation of tool usage was also performed. However, creating the digital mannequin was a lengthy and complex process. Moreover, the hand displacement distance used for the time calculation is linear. Furthermore, this calculation does not include the tightening time. The RULA analysis focused primarily on posture without including other risk factors. The OCRA Index and KIM-MHO methods helped to overcome these limitations by offering a more comprehensive ergonomic assessment. While the data glove proved useful for studying hand movements, it has limitations due to sensor displacement, making the data imprecise for biomechanical analysis in AnyBody Modeling System. Finally, the qualitative evaluation allowed for an examination of the tools, considering variables such as diameter, weight, materials, vibrations, and assembly forces. We recommend improving the digital mannequin creation process in Jack 7.1 and adding tools that enable a more complete ergonomic analysis of the studied work system, considering various factors contributing to the development of MSDs. For hand studies, new projects on the use of common assembly tools, such as pneumatic tools and torque wrenches, should be undertaken using data gloves with human participants. The hand model in AnyBody Modeling System (Regensburg-Ulm Hand Model) is particularly promising for conducting detailed biomechanical analyses. To achieve this, we recommend developing a project dedicated to designing data gloves suitable for accurate biomechanical analysis, addressing the issue of sensor displacement. This project should also include a study aimed at standardizing the necessary criteria to ensure the reliability and accuracy of the collected data.

Date	20 Dec 2024
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Sylvie Nadeau (Supervisor) & Kurt Landau (Co-supervisor)