ENGINEERING APPROACH FOR INTEGRITY ASSESSMENT ON THE STRUCTURE SUBJECTED TO REVERSED LOADINGS

Abstract

This study proposes three engineering approaches for the integrity assessment for the structure under reversed loadings. The study firstly develops a method to measure the fracture resistance curve under reversed loadings. This method treats the upper envelope of the cyclic load-deformation curve as a monotonic load-deformation curve. The measurement follows the single specimen technique, documented in ASTM-E1820, to calculate the cyclic fracture resistance curve with the equivalent monotonic curve. Subsequently, the study performs node release analysis to verify the validity of the above method for the measurement of cyclic fracture resistance curve. Based on the proposed method for cyclic fracture resistance curve measurement, this study proposes a reversed eta approach to estimate the load-deformation response of fracture specimens and cracked structural components under monotonic and reversed loadings. Finally, the study develops a tearing assessment diagram to predict the load-crack extension relationship during the ductile tearing process of a structural component.