Strain capacity is an important performance indicator for designing and evaluating high-grade steel pipelines.Due to the inhomogeneity of material properties in welded structures,girth welds are one of the main factor...Strain capacity is an important performance indicator for designing and evaluating high-grade steel pipelines.Due to the inhomogeneity of material properties in welded structures,girth welds are one of the main factors that restrict the strain capacity of pipelines.In this paper,girth-welded pipes with cracks in the inner surface of the weld have been studied,and the ductile crack initiation and propagation behavior have been simulated using the Gurson model.The corresponding nominal strain at the onset of crack initiation was defined as the characteristic value of strain capacity.The influencing factors on the strain concentration area,strain concentration factor,and strain capacity of girth-welded pipes were quantitatively analyzed.A semiempirical calculation formula for the strain capacity of typical girthwelded X80 grade pipes has been proposed as a function of the crack size,mismatch coefficient of the weld,and softening degree of the heat affected zone(HAZ).This study can facilitate the defect assessment of girth-welded pipes.展开更多
Nowadays,many research works are carried for all grades of concrete to make the concrete most economical and durable there by adding the supplementary cementitious materials and alternative replacement aggregates.In t...Nowadays,many research works are carried for all grades of concrete to make the concrete most economical and durable there by adding the supplementary cementitious materials and alternative replacement aggregates.In this research work deals with the experimental investigation of mechanical properties of the M30,M50 and M80 grade concrete by replacing the fine and coarse aggregate by foundry sand and crushed concrete waste respectively.Mix design procedures were followed as per IRC44:2017 guidelines and recommendation.Proper dosage of super plasticizer(SP)was maintained in the concrete to make it better performed.In this present investigation,a Poly Propylene fibre(PPF)of 0.3%by weight of the cement is used.Mechanical properties such as Compressive strength and Flexural Strength were determined by preparing the respective mould sizes for specific test and are cured for 7,14 and 28 days and result obtained for respective days were tabulated and discussed.展开更多
基金supported by the grants from the National Natural Science Foundation of China(Grant No.51874324)the Chinese Scholarship Council(CSC)for the financial support。
文摘Strain capacity is an important performance indicator for designing and evaluating high-grade steel pipelines.Due to the inhomogeneity of material properties in welded structures,girth welds are one of the main factors that restrict the strain capacity of pipelines.In this paper,girth-welded pipes with cracks in the inner surface of the weld have been studied,and the ductile crack initiation and propagation behavior have been simulated using the Gurson model.The corresponding nominal strain at the onset of crack initiation was defined as the characteristic value of strain capacity.The influencing factors on the strain concentration area,strain concentration factor,and strain capacity of girth-welded pipes were quantitatively analyzed.A semiempirical calculation formula for the strain capacity of typical girthwelded X80 grade pipes has been proposed as a function of the crack size,mismatch coefficient of the weld,and softening degree of the heat affected zone(HAZ).This study can facilitate the defect assessment of girth-welded pipes.
文摘Nowadays,many research works are carried for all grades of concrete to make the concrete most economical and durable there by adding the supplementary cementitious materials and alternative replacement aggregates.In this research work deals with the experimental investigation of mechanical properties of the M30,M50 and M80 grade concrete by replacing the fine and coarse aggregate by foundry sand and crushed concrete waste respectively.Mix design procedures were followed as per IRC44:2017 guidelines and recommendation.Proper dosage of super plasticizer(SP)was maintained in the concrete to make it better performed.In this present investigation,a Poly Propylene fibre(PPF)of 0.3%by weight of the cement is used.Mechanical properties such as Compressive strength and Flexural Strength were determined by preparing the respective mould sizes for specific test and are cured for 7,14 and 28 days and result obtained for respective days were tabulated and discussed.
