The performance analysis of three-dimensional (3-D) braided composites is more difficult due to its complex and interlacing
structure. Optical fiber sensors (OFS) can be used to co-braid into performs to measure the internal strain. This paper
introduces the different braiding ways of braided OFS and established the constitutive modeling of each. Experiments are
conducted to measure internal strain under tension environments in the three-dimensional braided composite specimens, they
are compared and analyzed with the theoretical results.