Desenvolvimento de uma máquina de ensaio mecânico para determinação do coeficiente de restituição em componentes de calçados / Development of a mechanical testing machine for determining the coefficient of restitution as components of footwear

ABSTRACT

Taking into consideration the importance of knowing mechanical properties of footwear components, this study aims to develop a mechanical testing machine able determine the restitution coefficient (RC) using the Conservation of Energy principle. The machine presents a "U" inverted shape, its both extremities (towers) having 40.00 x 10ˉ² m heigth, in which a 165.29 x 10ˉ³ kg freely falling body slips, having a piezoeletric sensor that after shocking the specimens produces an eletrical by an adjustable electromagnet making possible the variation of the heigth of fall. The machine is connected to a PC that makes possible the specimens release through an eletronic signal and also makes the signal acquisition and processing by SAD 32 software, which was developed by Mechanical Measurement Lab of the Federal University of the Rio Grande do Sul State. In this study, the machine was supported by a 1179.33kg/ m³ density wood block. Two new footwear midsoles were used and named specimen A and specimen B. The machine calibration was made separately for each specimen...