Autor(es): Figueira, Diogo ; Sena-Cruz, José ; Pereira, Eduardo ; Valente, Isabel B. ; Barros, Joaquim A. O. ; Castro, Fernando ; Soares, Delfim
Data: 2019
Identificador Persistente: https://hdl.handle.net/1822/65188
Origem: RepositóriUM - Universidade do Minho
Assunto(s): Polymeric foams; Polyisocyanurate; Shear creep; Findley’s power law; Polyisocyanurate (PIR); Temperature
An experimental campaign was carried out to assess shear creep behaviour of a rigid low-density closed-cell polyisocyanurate (PIR) foam. Two service temperature values were considered, 20 ºC and 30 ºC, and the applied stresses ranged between 20% and 60% of the corresponding shear strength. The results showed that a stress amplitude of 30% was enough to cause nonlinear creep response. Furthermore, creep deformations were slightly smaller in the tests at 30 ºC, a fact that matched the viscoelastic response of the PIR foam obtained from DMA testing. Finally, creep prediction curves were calibrated through an analytical approach based on the Findley’s power law.
