Design virtual and experimental comfort testers to predict and measure the static mechanical pressure (SMP) induced by earplugs on the ear canal walls
This internship is part of a major research project entitled "Development of a range of comfort indices for earplugs to improve the hearing protection of workers", conducted by a multidisciplinary team. The general objective of this project is to design a battery of hybrid objective/subjective comfort indices for earplug-type HPDs and provide tools (1) for OHS (Occupational Health & Safety) preventers to select earplugs that are more suited to the morphology and working conditions of workers (2) for manufacturers to integrate more efficiently the concept of comfort in the design phase of future earplugs.
In Quebec, deafness is the most widely recognized occupational disease and the number of workers affected is steadily increasing. The effectiveness of hearing protectors is often lower than expected, because they are badly worn or not long enough. The reason is well known: the protectors are uncomfortable.To design comfortable earplugs and to classify them, it is important to develop a series of comfort indices. The SMP induced by earplugs on ear canal walls is one of the source of discomfort. Currently, no test bench for measuring SMP exerted by an earplug on an ear canal is available. The development of such a test bench remains a challenge given the geometric complexity of the ear canal and the available sensor technologies. As far as the computation of the SMP is concerned, the existing publications are scarce and no model validation has been carried out yet.
The candidate will build finite element models to simulate the SMP induced by three types of earplugs (roll-down foam, premolded and custom molded) on the ear canal walls of an existing realistic artificial ear using an appropriate contact mechanics linear finite element software (LS-Dyna, Abaqus, Comsol) including geometrical non linearities. This includes assessing the mechanical properties of each component (earplug, synthetic ear canal wall materials) using the appropriate characterization methods. The candidate will also develop test benchs using adequate pressure sensors to validate these models. He will perform literature reviews and contribute to the writing of deliverables, articles and presentations.
• Ph.D. in computational mechanics, mechanical engineering;
• Knowledge of contact mechanics algorithms and softwares (ex Ls-Dyna, Abaqus, Comsol, …), ;
• Excellent interpersonal abilities and communication skills
• Familiarity with pressure sensors and mechanical pressure measurement is a plus;
• Be autonomous, resourceful and enjoy working as part of a team in a research project
• Be punctual, persistent and meet deadlines