Embedded Fiber Optic Sensors Within Additive Layer Manufactured Components

TLDR

Smart materials with integrated sensing capabilities are ubiquitous in composite structures, and additive layer manufacturing enables creation of complex parts with minimal shape restrictions, enhancing safety, reliability, and efficiency. The study investigates embedding optical fiber Bragg grating sensors into components produced by powder‑bed additive manufacturing. A commercial EOS P730 powder‑bed system embeds fiber‑Bragg‑grating sensors via a fiber‑carrier that replaces a placeholder during the build, and the resulting specimens—using polyimide or acrylic jacketed fibers—are tested under extended cyclic tensile loading. The embedded sensors exhibit stable, reproducible responses over more than 720 days and 311,000 load cycles, with deformation behavior varying according to the fiber jacket material.

Abstract

Smart materials with integrated sensing capabilities are now ubiquitous in many structures and devices manufactured from composite materials and they offer enhanced safety, reliability and efficiency in such smart devices. This paper explores the application of embedded sensors to components manufactured using additive layer manufacturing (ALM) technology. ALM offers the ability to create physical parts with little or no restriction in shape and complexity. In this paper, optical fiber sensors incorporating fiber Bragg gratings are embedded inside a component made by, and during a powder-bed-based, layer-by-layer, additive manufacturing process. A commercial EOS P730 system is used, where a laser is employed to sinter the polymeric powder into a 3D component. The fiber embedding approach is based upon insertion of a “fiber-carrier” component, which replaces a removable “place-holder” component during an interruption of the ALM build process. Tensile test specimens fabricated this way are subjected to extended cyclic tensile loading trials at low strain levels of up to 580 μe . The test specimens demonstrate stable and reproducible responses over a period in excess of 720 days and 311000 load cycles. Polyimide and acrylic jacketed fibers are trialled, and the resulting deformations of the component through internal stresses depending on the fiber jacket type are discussed.