报告人：韩国KAIST Sung-Kie Youn教授
题目：Topology optimization of viscoelastically damped structures under transient dynamic loading
Structures with enhanced damping capabilities are of great interest to various engineering applications. The structures are commonly excited by transient dynamic loading such as wind, shock and seismic loadings. In these applications, viscoelastically damped structure are often used to attenuate undesired responses. The damping forces in the system depend on the past history of motion via convolution integrals. The viscoelastic damping is modeled by the generalized Maxwell model.
Multi-material topology optimization is presented to develop structures involving multi-phase materials with the quasi-static assumption. The density approach is applied to obtain the distribution of viscoelastic and structural material simultaneously. The damping is characterized by viscoelastic dissipation energy of the structures under general time-dependent loading.
The extension of this approach to dynamic problems will also be introduced.The design sensitivity analysis method of the dynamic system is developed using the adjoint variable method. The discretize-then-differentiate approach is adopted for deriving discrete adjoint equations. Based on the derived sensitivities, topology optimization of damped shells structure is presented. The proposed method can be used to effectively mitigate the dynamic response of the damped structures.