The Poisson s Ratio Of Multi Material Honeycomb - 1104 Words

As discussed in chapter 4, the Poisson’s ratio of multi-material honeycomb reentrant structure is tunable in method of changing E_r/E_v values. In order to prove the analytical simulation, the author has chosen the following Young’s modulus couple shown in Table 6-1. Table 6 1. Honeycomb reentrant samples composition Sample No. Reentrant struts E_r Vertical struts E_v E_r/E_v Flexible-FlexSL4 Flexible 10MPa FlexSL4 200MPa 0.05000 FlexSL4-Flexible FlexSL4 200MPa Flexible 10MPa 20.0000 Flexible-FlexSL5 Flexible 10MPa FlexSL5 152.2MPa 0.06557 FlexSL5-Flexible FlexSL5 152.2MPa Flexible 10MPa 15.2500 Flexible-FlexSL6 Flexible 10MPa FlexSL6 86MPa 0.11628 FlexSL6-Flexible FlexSL6 86MPa Flexible 10MPa 8.60000 Flexible-FlexSL7 Flexible 10MPa FlexSL7 54.5MPa 0.18349 FlexSL7-Flexible FlexSL7 54.5MPa Flexible 10MPa 5.45000 Flexible-FlexSL8 Flexible 10MPa FlexSL8 30MPa 0.30303 FlexSL8-Flexible FlexSL8 30MPa Flexible 10MPa 3.30000 There are four geometrical design parameters for the multi-material honeycomb re-entrant unit cell structure: vertical strut height H, re-entrant struts length L, the re-entrant angle ÃŽ ¸, and the strut cross section side length t. According to EMSL system’s manufacturing characteristic, these four parameters are chosen to be: ÃŽ ¸=60Â °, H / L / t = 10:5:1. Having these parameters, the re-entrant struts and vertical struts are designed in Solidworks and then assembled into lattice in Netfabb. Note that the entire lattice is divided into two material sets, so the