進化計算を用いた床振動制御用TMDの最適設計
主に鉄骨造の建物において歩行などによる床振動が問題となることがある。その場合，一般的に床スラブとOAフロアの間に複数のTMD (Tuned Mass Damper, 同調質量ダンパー)を設置して，床振動を低減するという対策がとられる。TMDが効果的に作用するためには，同調振動数と減衰比という二つのパラメータを，設置する床に応じて適切に設計する必要がある。従来は複数のTMDを設置する場合であっても大きな一つのTMDと見なして，単一TMDの設計方法である定点理論に従って設計していたが，最適な設計ができておらず，本来の性能を発揮できていない可能性があった。本研究では，AIの一種である進化計算を用いて床振動制振用TMDの最適設計技術を開発し，実建物においてその有効性を検証した。TMDを設置した鉄骨造の床で歩行振動を測定したところ，定点理論で設計した10台のTMDと同等の制振効果を，進化計算で設計したTMDは6台で得ることができた。
キーワード：同調質量ダンパー，床振動，環境振動，進化計算，数理最適化
＊１ 技術センター 先進技術開発部 AI連携技術開発室
Optimum Design of TMDs to Suppress Floor Vibration Using Evolutionary Computation
Perceptible floor vibration occurs infrequently due to human activities such as walking, mainly in steel framed buildings. A general strategy to reduce the floor vibration is to install Tuned Mass Dampers (TMDs) between a floor slab and a raised OA floor. Two parameters of a TMD, resonance frequency and damping ratio, should be designed properly depending on the dynamic characteristics of the target floor so that the TMD acts effectively. Conventionally, even when installing multiple TMDs to a floor, they have been regarded as one large TMD and the fixed theory, which is a method to design a single TMD, has been applied. However, with this method the design cannot be optimized, and there is a possibility that the intrinsic performance of the system cannot be realized. We have developed an optimum design system for TMDs to reduce floor vibration using evolutionary computation, which is a subfield of artificial intelligence, and verified its effectiveness in an actual building. Vibrations due to people walking on a structural steel floor to which TMDs had been installed were measured. The results showed that six TMDs designed by evolutionary computation achieved vibration suppression performance equivalent to 10 TMDs designed by the fixed theory.
Keywords: tuned mass damper, floor vibration, environmental vibration, evolutionary computation, mathematical optimization
*1 AI Utilization Technology Development Section, Advanced Technology Development Department, Taisei Advanced Center of Technology