Abstract: Changing thickness honeycomb core material for high performance broadband radome is conventionally machined by multiple degree machining systems on three dimensional molds, which needs a lot of time and costs and is less flexible. In this article, the radome surface was cut into a set of narrow strips of surfaces, then discretize each narrow strip of surface into a clustered of adjacent triangle planes. Afterwards the present work utilizes the in-plane flexibility of honeycomb material and apply the mathematical expansion methods and equal-area micro-transforming methods to expand the three dimensional surface into a corresponding planar pattern. This process creates a corresponding planar point for each three dimensional points. Thus, the changing thickness honeycomb core material that is widely used for modern broad-band radomes can be machined on a conventional three-degree freedom machine instead of on a complex four-degree freedom machine that needs expansive cutting molds or cost elongated time. This lowers the requirement on the machinery and machining fixtures and increases the flexibility for the honeycomb material machining in time of repair and maintenance.

Key words: changing thickness, honeycomb material, sandwich radome, expanded honeycomb milling