2 research outputs found
Surface roughness evolution in hardened steel disks: an integrated profilometry and ansys-fea approach to assess contact conditions and residual stress profiles
This thesis investigates the impact of the running-in process on the surface roughness
of hardened and ground steel disks, which simulate gear tooth contact conditions. The
focus is on the changes in asperity shape due to plastic deformation and the associated
residual stresses at the asperity scale. In-situ profilometry quantifies these shape
changes, particularly in areas with high plastic deformation and tensile residual stress,
which could lead to surface micropitting during further use.
A novel method for repositioning and aligning measured surface profiles from mixed
lubrication experiments is presented. Finite element analysis (FEA) using ANSYS
software is central to this study, encompassing both elastic and plastic contact
analyses. The analysis starts with standard smooth elastic body contacts, validated
against Hertzian elastic solutions, and extends to include plastic behaviour, aligning
with established models. Various numerical case studies improved the predictive
accuracy of FEA, with increased mesh resolutions enhancing result precision and
scaled-down loading conditions managing convergence issues effectively.
The FEA simulations incorporate real surface profiles to assess how ground steel disk
surfaces react under different loads. By comparing profiles before and after loading, a
detailed representation of elastic/plastic interactions on real rough surfaces is achieved
within the ANSYS environment. This method predicts residual stress profiles beneath
select asperities.
Validation of the FEA analysis is conducted through a comparative study using an
innovative depth-profiling residual stress measurement technique. This technique
utilizes Focused Ion Beam (FIB) milling and digital image correlation to measure
near-surface residual stresses within asperities up to a depth of 3 microns, providing
accurate validation and aligning with experimental measurements.
Additionally, the thesis includes an appendix with detailed, step-by-step instructions
for conducting FEA contact modelling using ANSYS software, supported by visual
figures. The appendix also contains extensive comparative analyses to validate the
FEA results against analytical solutions
Proceedings of First Conference for Engineering Sciences and Technology: Vol. 2
This volume contains contributed articles of Track 4, Track 5 & Track 6, presented in the conference CEST-2018, organized by Faculty of Engineering Garaboulli, and Faculty of Engineering, Al-khoms, Elmergib University (Libya) on 25-27 September 2018.
Track 4: Industrial, Structural Technologies and Science Material
Track 5: Engineering Systems and Sustainable Development
Track 6: Engineering Management
Other articles of Track 1, 2 & 3 have been published in volume 1 of the proceedings at this lin