Two-dimensional nonlinear energy sink for effective passive seismic mitigation

• Published in: Communications in nonlinear science & numerical simulation 2021-08, Vol.99, p.105787, Article 105787
• Main Authors: Saeed, Adnan S., AL-Shudeifat, Mohammad A., Cantwell, Wesley J., Vakakis, Alexander F.
• Format: Article
• Language: English
• Subjects: Absorbers; Earthquake loads; Nonlinear dynamics; Nonlinear equations; Nonlinear systems; Numerical analysis; Optimization; Robustness (mathematics); Seismic engineering; Seismic mitigation; Seismic response; Structural failure; Targeted energy transfer; Two dimensional nonlinear energy sink; Vibration absorber; Vibration analysis; Vibration control
• ISSN: 1007-5704; 1878-7274
• DOI: 10.1016/j.cnsns.2021.105787

•Current studies in targeted energy transfer have focused mainly on uni-directional vibration absorbers for mitigating high-amplitude vibrations.•A two-dimensional nonlinear passive absorber (2D-NES) is proposed to passively and robustly suppress multi-directional seismic excitations applied to a primary structure.•The 2D-NES is optimized numerically for a severe seismic excitation using a set of quantitative measures.•The 2D-NES's robustness is verified using alternative seismic excitations with different frequency and energy contents.•The results demonstrate that the optimized 2D-NES is capable of effectively and rapidly suppressing seismic, multi directional excitations. Structures and machines are often exposed to sudden high-amplitude vibrations that may cause local or extended structural failure. This calls for effective and reliable methodologies for vibration mitigation, one of which is the use of linear or nonlinear dynamic vibration absorbers. Current studies in this area have focused mainly on uni-directional vibration absorbers, thus limiting their applicability in practical applications where the excitation is applied in the plane. For example, real-life structures are subjected to a multitude of multi-directional seismic excitations, so uni-directional devices for mitigating such effects would have limited effectiveness. Accordingly, in this work we propose a two-dimensional nonlinear passive absorber, which we term two-dimensional nonlinear energy sink (2D-NES), and investigate its efficacy to robustly suppress seismic excitations in arbitrary directions on the plane. First, a numerical optimization process is formulated to optimize the 2D-NES for the especially severe Kobe seismic excitation through a set of quantitative measures related to the seismic response of the primary structure. Then, its robustness is confirmed by applying two additional historic earthquakes with different frequency and energy contents. The results demonstrate that the optimized 2D-NES is capable of effectively and rapidly suppressing seismic, multi directional excitations. This work is one of the first studies of 2D nonlinear vibration absorbers capable of robust passive mitigation of seismic loads applied in arbitrary planar directions. This design can be suitable for broad applications ranging from the nano/micro- to the macro-scale.