TMD's Optimization for Dynamic Analysis of Walkways Excited by Pseudorandom Pedestrian’s Load

Resumo

In this work, optimization of vibration absorbers (TMD) will be presented for dynamic analysis of walkways in aerospace structures excited by pedestrians. The dynamic loading used to excite the walkway will be a pseudorandom model. Using this type of loading, it is possible to cover a band of frequencies and amplitudes of possible excitation to the structure, similar to a PSD. The deterministic dynamic loading used as a basis is the Schulze loading. First, a simply supported beam representing a walkway will be modeled via a commercial FEM software to obtain modal mass, modal stiffness and frequency. Next, a two-degree-of-freedom model of the critical vibration mode of the structure close to the excitation frequency is presented, with a vertical TMD and a horizontal TMD, the latter modeled as a pendulum. Using MATLAB tools, the TMD mass ratio is optimized using as
objective function the minimization of the difference between the maximum acceleration of the system and limit
accelerations recommended by standards of human comfort. These optimal parameters will be carried back to the
FEM model for comparisons.