Topic of Research Seminar: Environmental Aging of Fiber Reinforced Polymer Matrix Composite(PMC) Radome

Abstract: Efficient, long term and reliable electromagnetic performance of radome is essential for high speed communication. They protect antennas from environmental impacts, physical damage, and aerodynamic loads while keeping the overall radome-enclosed-antenna electric performance intact. Their long term-reliable performance and structural integrity depends on their consistency in dielectric properties, mechanical integrity and least moisture absorption. The current study aims at the dielectric properties over wideband frequency and impact of environmental aging on the fiber-reinforced-PMC radome. High-silica fibers reinforced/epoxy composite radome (SF/Ex) and test samples were fabricated (fibers 40 to 90 (wt.%)). The Ɛr of SF/E0.8 composite radome material, (80 % fiber loading) was decreased to 4% from its initial value (3.93) and δ was 11 % decreased from 0.035 (2-18 GHz). SEM images showed the fair fiber/matrix adhesion and interface bonding of composite. Derived from Hallberg-Peck model, from 5 to 25 years aging time, variation of dielectric constant (Ɛr), dielectric loss (δ), moisture absorption, and tensile properties was experimentally determined. Upon accerlated aging (time=5-25 yr), moisture uptake in the SF/E0.8 composite was increased from 1.13 % to 1.67 % , the tensile strength was decreased (146.3 MPa to 115.34 MPa), compression strength (380.66 MPa to 330.54 MPa), flexural strength (285.54 MPa to 227.02 MPa) and ILSS (20.33 MPa to 13.56 MPa) respectively. The SF/E0.8 radome performance (Ɛr, δ, Gain and VSWR) was slightly varied from initial values, however the mechanical properties were decreased gradually due to weakening of fiber-matrix adhesion over the extended aging time. Despite the variation of properties, the SF/Ex composite electrical performance, low is still reliable and effective for radome applications.

Subject Field of Topic: Wave transparent Composite, Aging

Name of Speaker: Imran Haider

Professorial Rank of Speaker: PhD scholar

University Email of Speaker: [email protected]

Affiliation of Speaker: School of Chemical and Materials Engineering, NUST

Date and Venue: November 21, 2023, at 1500 hrs, Seminar Hall, School of Chemical and Materials Engineering, NUST Islamabad Campus