A lumped mass human model is proposed to minimize the energy absorption at the feet and hip level of the human body, subjected to vertical vibration. The optimum damping and stiffness coefficients of shoes are evaluated by the dynamic response of the human body. The contact forces are modelled are stiffness and damping forces. The coefficients are optmised such that the human body responses in the frequency domain assumes the minimum energy. The optmisation technique is based on quasi-Newton method to estimate optimal coefficients of the contact forces. As before mentioned, the optimal solution of the body's response is obtained in the frequency domain 0-15 Hz. In the standing postures, the frequency response shifts the peak of resonance of each human body segment from 3-4 Hz to 2-2.5 Hz. The coefficients of the damping and spring forces for the minimum energy associated with displacement, velocity, acceleration and internal forces are respectively, kopt=0.1 kNs/m and kopt=10 kNs/m. In addition, the optimal parameters reduce drastically total energy during contact conditions. The furure development of this research can be manufactured optmised shoes.
Optimization of the contact damping and stiffness coefficients to attenuate vertical whole body vibration
Cavacece Massimo
Membro del Collaboration Group
2017-01-01
Abstract
A lumped mass human model is proposed to minimize the energy absorption at the feet and hip level of the human body, subjected to vertical vibration. The optimum damping and stiffness coefficients of shoes are evaluated by the dynamic response of the human body. The contact forces are modelled are stiffness and damping forces. The coefficients are optmised such that the human body responses in the frequency domain assumes the minimum energy. The optmisation technique is based on quasi-Newton method to estimate optimal coefficients of the contact forces. As before mentioned, the optimal solution of the body's response is obtained in the frequency domain 0-15 Hz. In the standing postures, the frequency response shifts the peak of resonance of each human body segment from 3-4 Hz to 2-2.5 Hz. The coefficients of the damping and spring forces for the minimum energy associated with displacement, velocity, acceleration and internal forces are respectively, kopt=0.1 kNs/m and kopt=10 kNs/m. In addition, the optimal parameters reduce drastically total energy during contact conditions. The furure development of this research can be manufactured optmised shoes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
