The curing of epoxy adhesives is a complex phenomenon where the thermal, the chemistry and the mechanics are coupled. Corresponding material properties such as mechanical and physics properties are evolving with the curing. This paper focuses on their predictions by a multiphisics FEM approach of the thermal, chemical and mechanical couplings involved by the curing for a novel assembly of radio telescope panel. The first part presents the constitutive model of an epoxy adhesive that is considered for the curing. The numerical solving, performed with a specific user subroutine of Ansys, is detailed and allows the study of real three-dimensional structure parts. Residual stresses and strains of different metallic membranes and internal adhesives in the interconnect during the assembly of radio telescope panel are investigated. The mechanical response of the interconnect is analyzed with respect to the poisson’s ratio, relaxation time and adhesive thickness. It is shown that, although the overall residual stresses at the interconnect increase with the adhesive curing, the local strains have different evolving trends, indicating the possibility of damage and decohesion that might compromise mechanical integrity and interrupt the component processing precision.

Date Published: 18 July 2014
PDF: 14 pages
Proc. SPIE 9151, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation, 915132 (18 July 2014); doi: 10.1117/12.2055397

Published in SPIE Proceedings Vol. 9151:
Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation
Ramón Navarro; Colin R. Cunningham; Allison A. Barto, Editor(s)