Modelagem matemática e comportamento dinâmico da suspensão passiva de um pulverizador agrícola autopropelido

• Ano de defesa: 2008
• Autor(a) principal: Ferreira, André Luiz [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Agricultural machines; Agricultural sprayer; Passive suspension; Numerical simulations; Máquinas agrícolas; Pulverizador agrícola; Suspensão passiva; Simulações numéricas
• Link de acesso: http://hdl.handle.net/11449/136686; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/21-03-2016/000556918.pdf

This paper is based on the elaboration of mathematical suspension models which can evaluate performance parameters of an agricultural vehicle based on the vibration caused by irregularities on the soil surface. In this paper, these irregularities are represented by step input, sine input and obstacles of leveled road according to ISO 5008 specifications. The motion equations are obtained from the mathematical models of a quarter car and half car. Numerical simulations are performed on Matlab®, Simulink® and Visual Nastran®. Based on known input, characteristics of suspension elements can be determined in order to obtain desired levels of comfort and safety. Different system configurations were analyzed changing the stiffness ratio and the damping coefficient based on a standard model. Results were treated statistically and compared among themselves. It was verified that the increase in stiffness ratio results in the reduction of the vertical acceleration and in the increase of the suspension travel, improving comfort but reducing safety. On the other hand, the reduction of damping coefficient causes the reduction of vertical acceleration up to a certain point, and from this point on the acceleration increases again. The suspension travel, however, reduces as damping coefficient is reduced.