Structural dynamics

The research focuses on:

  • The study of damage and material fatigue.
  • Implementation of technical control of noise and vibration.
  • Modal analysis of structures.

Projects related to the dynamics of machines:

Numerical and experimental modeling of fretting fatigue in surface-hardened gears (P. Bocher and R. Guilbault; one Doctorate student)

Joint studies are underway between Professor Bocher P. and Pratt & Whitney Canada to increase gear assemblies hardness through induction , and there are plans to continue the CRIAQ5 project in the longer term. Professors Bocher and Guilbault are currently co-supervising a Doctorate student whose project examines the induction-based digital modeling of fretting fatigue in surface-hardened gears. Moreover, to validate the developed model’s ability to recognise the presence of materials with varying degrees of hardness, part of the research is devoted to an experimental campaign. The experimental campaign will be conducted on a fretting fatigue test bench designed and manufactured at ÉTS. Because these fatigue tests are conducted with lubricants present, no commercial device for generating loads showing typical conditions has been identified. Although the system will soon be tested, the assembly complexity would seem to indicate that several corrections and adjustments must be implemented. Furthermore, the nature of the concepts studied requires detection methods that are yet to be developed. Although plans are underway to use vibration measure and visual inspection detection methods, these approaches may very well not allow for the timely detection of early signs of fatigue. Since fretting fatigue often begins below the surface, its detection is indeed difficult. As a result, it is therefore likely that more expensive detection techniques will be implemented.

An Experimental Study of Fretting Fatigue in Gears – The Effects of Operating Conditions (R. Guilbault; one Doctorate student)

The preceding device will also be used for another Doctorate project supervised by Professor Guilbault.  The experimental study will use the same sample type as the last project. However, the test campaign will be more extensive, and will examine the following parameters: the effects of curvatures and dimensions, the effects of sliding velocity and the effects of lubricant viscosity. Both projects are complementary, with the last one focusing entirely on studying the effects of the presence of hard surfaces. As a result, the large number of tests planned will lead to the degradation of the setup itself. Since some of the device’s components will in fact have a fatigue life spanning several tests (4 or 5), they will therefore need to be replaced during the projects.