In this study,the technical papers on structural condition assessment of aged fixed-type offshore platforms reported over the past few decades are presented.Other ancillary related works are also discussed.Large numbe...In this study,the technical papers on structural condition assessment of aged fixed-type offshore platforms reported over the past few decades are presented.Other ancillary related works are also discussed.Large numbers of researches are available in the area of requalification for life extension of offshore jacket platforms.Many of these studies involve reassessment of existing platforms by means of conducting pushover analysis,a static nonlinear collapse analysis method to evaluate the structure nonlinear behaviour and capacity beyond the elastic limit.From here,the failure mechanism and inherent reserve strength/capacity of the overall truss structure are determined.This method of doing reassessment is described clearly in the industry-adopted codes and standards such the API,ISO,PTS and NORSOK codes.This may help understand the structural behaviour of aged fixed offshore jacket structures for maintenance or decommissioning.展开更多
The force analogy method(FAM) is considered as one of the most time-saving and cost-efficient methods for analyzing frames. Through a set of assumptions and restoring forces, FAM analyzes nonlinear frames responses th...The force analogy method(FAM) is considered as one of the most time-saving and cost-efficient methods for analyzing frames. Through a set of assumptions and restoring forces, FAM analyzes nonlinear frames responses through Hooke’s law. This study evaluates the effect of element type on FAM through numerical and experimental tests. The conventional Euler Bernoulli(EB) element is replaced by the Timoshenko(TS) beam-column element and the results are interpreted and compared with experimental findings. Three experimental tests were conducted for benchmarking and comparison purposes via 2 D aluminum frames. The results indicated that during the analysis, when the frame response is in the linear region, there is no difference between the element types in the response of the frames. When the frame entered the plastic region, the frames which were analyzed by the TS element revealed closer responses to the experimental outcomes. The gap between the results of the frame which was analyzed by EB and TS enlarged especially when the frame experienced a sharp or huge rotation of more than 0.2 rad. The final recorded deformations based on the TS element revealed an accuracy between 98.05% to 98.65%, while the EB element showed 14.66% to 45.14% for rotations of more than 0.2 rad at plastic hinge locations(PHLs).展开更多
基金This research was supported by the Yayasan Universiti Teknologi PETRONAS(YUTP)(Grant No.15-8209-054)Technology Innovation Program(Grant No.10053121)funded by the Ministry of Trade,Industry&Energy(MI,Korea).This research is part of Dr.Mubarak’s PhD thesis.
文摘In this study,the technical papers on structural condition assessment of aged fixed-type offshore platforms reported over the past few decades are presented.Other ancillary related works are also discussed.Large numbers of researches are available in the area of requalification for life extension of offshore jacket platforms.Many of these studies involve reassessment of existing platforms by means of conducting pushover analysis,a static nonlinear collapse analysis method to evaluate the structure nonlinear behaviour and capacity beyond the elastic limit.From here,the failure mechanism and inherent reserve strength/capacity of the overall truss structure are determined.This method of doing reassessment is described clearly in the industry-adopted codes and standards such the API,ISO,PTS and NORSOK codes.This may help understand the structural behaviour of aged fixed offshore jacket structures for maintenance or decommissioning.
文摘The force analogy method(FAM) is considered as one of the most time-saving and cost-efficient methods for analyzing frames. Through a set of assumptions and restoring forces, FAM analyzes nonlinear frames responses through Hooke’s law. This study evaluates the effect of element type on FAM through numerical and experimental tests. The conventional Euler Bernoulli(EB) element is replaced by the Timoshenko(TS) beam-column element and the results are interpreted and compared with experimental findings. Three experimental tests were conducted for benchmarking and comparison purposes via 2 D aluminum frames. The results indicated that during the analysis, when the frame response is in the linear region, there is no difference between the element types in the response of the frames. When the frame entered the plastic region, the frames which were analyzed by the TS element revealed closer responses to the experimental outcomes. The gap between the results of the frame which was analyzed by EB and TS enlarged especially when the frame experienced a sharp or huge rotation of more than 0.2 rad. The final recorded deformations based on the TS element revealed an accuracy between 98.05% to 98.65%, while the EB element showed 14.66% to 45.14% for rotations of more than 0.2 rad at plastic hinge locations(PHLs).
