Thermo-vibratory analysis of engineering components
Prof E Patterson
Mr C Sebastian
Applications accepted all year round
Funded PhD Project (UK Students Only)
There is an increasing need for structural components to operate in extreme conditions characterized by thermal and mechanical excitation associated with, for instance hypersonic flight and advanced fusion reactors. Good progress has been made in developing materials for such applications but there are substantial technology gaps associated with assessing of the performance of structures in these extreme conditions.
In this project we will focus on the measurement of strain fields in simple engineering structures operating at temperatures up to 1600°C and subject to thermo-acoustic loading. Our primary interest will be to acquire stress and strain data for reinforced panels which modelling has predicted exhibit mode shifting and jumping at high temperatures. We will build on proof-of-principle work in which we have demonstrated the viability of measuring deformation of A5-size panels of Hastelloy X at temperatures between 600 and 800°C when they are subject to broadband or resonant excitation using both digital image correlation and thermoelastic stress analysis. These capabilities will be extended to higher temperatures (up to 1600°C) and frequencies up to 1kHz for larger panels. In addition, we will attempt to evaluate dissipated strain energy, or hysteresis energy directly. Hysteresis energy is well-known to be an indicator of damage but its direct evaluation in test panels is not possible at the moment. The research will involve fundamental work in experimental mechanics with contributions from structural dynamics, damage mechanics and high temperature phenomena. The outcomes will permit displacement and strain fields to be acquired in engineering components operating in extreme conditions of temperature and excitation. The data will be used in the validation of computational mechanics models which is a key step in providing confidence in engineering designs, particularly those used in safety critical applications in the aerospace and energy sectors.
You will join an international research group of about ten people working on a set of connected projects in well-equipped laboratories. There will be opportunities to interact with industry and to present your research to engineering community. On completion of the project you will be an expert in stress and strain analysis for high temperature structures, validation techniques for computational mechanics models and be skilled in both computational and experimental mechanics.
Funding is available to support UK citizens only.
Labeas, G., Pasialis, V.P., Lin, X. & Patterson, E.A., 2015, On the validation of solid mechanics models using optical measurements and data decomposition, Simulation Modelling Practice & Theory, 52:92-107.
Berke, R.B., Sebastian, C.M., Chona, R., Patterson, E.A., & Lambros, J., High temperature vibratory response of hastelloy-X: stereo-DIC measurements and image decomposition analysis, Experimental Mechanics, doi: 10.1007/s11340-015-0092-3