# Optical Fiber Current Sensors Based on FBG and Magnetotstrictive Composite Materials
## 3 Optical Fiber Current Sensor Based on Magnetostirctive Composite Materials
### Magnetstrictive Composites
Magnetic fields of 0 kA/m, 50 kA/m, 80 kA/m and 100 kA/m were applied in the preparation of magnetostrictive composites. It was found that the magnetostrictive strain of the composites gradually increased with the increase of orientation magnetic field strength. When the orientation magnetic field intensity is 100 kA/m, the magnetostrictive strain of the composites is the largest. As shown in Table 3, this paper summarizes the factors affecting the properties of magnetostrictive composites. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Serial** & **Influencing Factors of** & **Views of Different Authors** \\
**Number** & **Properties of Composite Materials** & 1. [PERSON] et al. think that the optimum preloading stress is 9 MPa \\ \hline  & & 2. [PERSON] et al. think that the optimum preloading stress is 8.6 MPa \\
**1** & **Preloading stress** & 3. [PERSON] et al. think that the best preloading stress is 10 MPa \\  & & 4. [PERSON] et al. think that the best preloading stress is 2 MPa \\  & & 5. [PERSON] et al. think that the best preloading stress is 6 MPa \\  & & 6. [PERSON] et al. the optimum preloading stress is 14 MPa \\  & & 7. [PERSON] et al. think that the best preloading stress is 17 MPa \\ \hline
**2** & **Orientation magnetic field direction** &
\begin{tabular}{c} GMPC with vertical orientation magnetic field direction is better \\ than GMPC with parallel orientation magnetic field direction \\ \end{tabular} \\ \hline  & & 1. [PERSON] et al. believe that the optimal orientation \\  & & magnetic field strength of GMPC with particle volume fractions \\  & & of 20\%, 30\%, and 50\% are 30 kA/m, 80 kA/m and \\
**3** & **Orientation magnetic field strength** & 100 kA/m, respectively. \\  & & 2. [PERSON] et al. think that the best orientation magnetic field is \\  & & 8000 Oe. \\  & & 3. [PERSON] et al. think that the best orientation magnetic field is \\  & & 100 kA/m \\ \hline
**4** & **Particle surface treatment** &
\begin{tabular}{c} GMPC treated with coupling agent is better than GMPC \\ untreated with coupling agent \\ \end{tabular} \\ \hline
**5** & **Types of adhesives** &
\begin{tabular}{c} Epoxy resin is superior to polyurethane resin \\ \end{tabular} \\ \hline
**6** & **Segment soft-hard ratio** &
\begin{tabular}{c} C. [PERSON] et al. think that the best segment soft-hard ratio \\ is 1.5 \\ \end{tabular} \\ \hline
**7** & **Temperature** &
\begin{tabular}{c} [PERSON] et al. think that the best temperature is 0 \({}^{\circ}\)C \\ or 10 \({}^{\circ}\)C \\ \end{tabular} \\ \hline
**8** & **Particle volume fraction** &
\begin{tabular}{c} 1. [PERSON] thinks that the best particle volume fraction is 30\% \\ 2. [PERSON] et al. think that the best particle volume fraction \\ is 57\% \\ 3. [PERSON] et al. think that the best particle volume fraction is 50\% \\ 4. [PERSON] et al. think that the best particle volume fraction is 85\% \\ \end{tabular} \\ \hline
**9** & **Particle mass fraction** &
\begin{tabular}{c} 1. [PERSON] et al. think that the best particle mass fraction is 90\% \\ 2. [PERSON] et al. think that the best particle mass fraction is 70\% \\ 3. [PERSON] and others believe that the best particle mass fraction is 93\% \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Research Summary of Magnetostrictive Composites.