Nonlinear Dynamics of Structures with Material Degradation

13th International Conference on Motion and Vibration Control; 12th International Conference on Recent Advances in Structural Dynamics

Soltani, P.^1 ; Wagg, D.J.^1 ; Pinna, C.^2 ; Whear, R.^3 ; Briody, C.^3

Dynamic Research Group, University of Sheffield, S13JD, United Kingdom^1

Department of Mechanical Engineering, University of Sheffield, S13JD, United Kingdom^2

Jaguar Land Rover Ltd, CV35 0RR, United Kingdom^3

关键词: Bifurcation parameter;    Material degradation;    Non-linear response;    Numerical continuation;    Temperature-dependent material;    Temperature-induced;    Thermal environment;    Thermo mechanical fatigues (TMF);   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/744/1/012123/pdf
DOI  :  10.1088/1742-6596/744/1/012123

来源: IOP

【 摘 要 】

Structures usually experience deterioration during their working life. Oxidation, corrosion, UV exposure, and thermo-mechanical fatigue are some of the most well-known mechanisms that cause degradation. The phenomenon gradually changes structural properties and dynamic behaviour over their lifetime, and can be more problematic and challenging in the presence of nonlinearity. In this paper, we study how the dynamic behaviour of a nonlinear system changes as the thermal environment causes certain parameters to vary. To this end, a nonlinear lumped mass modal model is considered and defined under harmonic external force. Temperature dependent material functions, formulated from empirical test data, are added into the model. Using these functions, bifurcation parameters are defined and the corresponding nonlinear responses are observed by numerical continuation. A comparison between the results gives a preliminary insight into how temperature induced properties affects the dynamic response and highlights changes in stability conditions of the structure.