Experimental study of pipeline deformation monitoring using the inverse finite element method based on the iBeam3 element

•Using an iFEM based on the iBeam3 element for pipeline deformation monitoring.•A two-node straight beam element, iBeam3, is introduced and developed in detail.•The effectiveness of the proposed method is verified by a numerical simulation test.•The accuracy of the proposed method is verified by an experimental test.•Application of pipe deformation monitoring during the freeze–thaw process of soil. This paper presents a novel pipeline deformation monitoring method using the inverse finite element method (iFEM) based on the iBeam3 element. This element uses only two end nodes to reconstruct pipeline deformation without any material and/or loading information because only the strain–displacement relationship is employed in the algorithm. A series of experimental studies is conducted to validate the effectiveness and accuracy of the presented method. The maximum error of the pipe node displacement in the numerical simulation is 4.1%, and the average error in the experimental test combined with the data from fiber Bragg grating (FBG) strain sensors is 7.96%. An application of pipe deformation monitoring during the freeze–thaw process of soil is conducted, and the test results demonstrate that the presented method can effectively monitor the deformation process for a buried pipe during the freeze–thaw process of soil with a measurement error of 15.43%, showing potential in practical engineering.