In-situ monitoring of strain and temperature distributions during fused deposition modeling process

Abstract The present work investigates the integration of fiber Bragg grating (FBG) sensors for continuous in-situ and in real-time monitoring of strain fields build up as well as of developed temperature profiles during the fabrication procedure of structures built via the Fused Deposition Modeling (FDM) technology. A methodology is presented for simultaneous monitoring of strain and temperature profiles from the recorded spectrum of an embedded optical sensor when the deposited material remains close to its glass transition temperature. The used FBG sensors were embedded either longitudinally or transversely to the test samples' long axis and within different layers of the structures. Analysis of the FBG recordings indicates that the generated residual strain values are significant during material consolidation of the deposited layers. It is also shown that the solidification induced strain levels and the developed temperature gradients are strongly influenced by the samples' position onto the building platform. The findings demonstrate that an embedded optical sensing system is proven to be a reliable choice for real-time monitoring of the FDM process and the printed part's quality.