A study for optical fiber multi-direction strain monitoring technology

Distributed measurement is truly achieved by Pulse-Pre Pump Brillouin Optical Time Domain Analysis (PPP-BOTDA) technique with its high spatial resolution and strain precision. A systematic distributed fiber-optic multi-direction strain monitoring (FOMDSM) technology is proposed according to the basic monitoring principle, testing parameters and layout scheme based on PPP-BOTDA. The reasonable layout scheme, temperature compensation formula, etc are also given. This article also determines the more reasonable specimen size, the position of optical fiber layout and the basic layout range. The article is an experimental feasibility inquiry into spatial multi-direction stain simultaneous monitoring, which is an urgent problem to be solved. The structure is not merely under drawing force in a practical project, and therefore this article also explores the studies common combination of bending and drawing in engineering, besides the tensile test. The technique utilizes the highest spatial resolution for the research field. From the monitoring efficacy, the high precision and good practical application have emerged. The article's final purpose is to be proved reasonable and applicable in putting forward the spatial multi-direction stress and strain monitoring idea by the common 0°/45°/90° strain monitoring based on PPP-BOTDA technology. It illustrates important guiding significance for forming actually spatial FOMDSM ability.