Basic principle and structure of concrete embedded FBG sensor is introduced.Considering how to set relavant parameters of sensor sheath

to optimize sensor performance.Analysis is carried out mainly through compressed rod stability of sheath in service and impact on strain transfer

to obtain effect of relatvant parameter on them.Combining these can obtain that when flexibility of sheath is the maximum critical value

the thickness of sheath is 0.2

0

.3 mm

impact of sensor sheath on tested structure to minimum;at the same time

it can satisfy feasibility of sensor fabrication

and strain transfer efficiency can reach to 99 %

so standard encapsulation of sensor is achieved.