Long period grating fibre sensor for detection of impurities infesting smart polymer composites

•Detection of composite and/or nanocomposites infestation with impurities using a LPGFS mounted into a SILPG setup is simulated.•The impurities detection is accomplished using chemical interaction with outer optic fibre surface and/or mechanical strain induced into LPGFS by stress caused by impurities infiltration.•For both detection mechanisms are developed simulation models.