Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be...Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.展开更多
The conformity of Saudi dates cultivars to date standards has not been studied extensively. In this study, microbial loads and physicochemical characteristics of four Saudi date cultivars (Sukkary, Khalas, Sugai and A...The conformity of Saudi dates cultivars to date standards has not been studied extensively. In this study, microbial loads and physicochemical characteristics of four Saudi date cultivars (Sukkary, Khalas, Sugai and Anbara) were determined. Anbara cultivar had significantly higher mould and yeast counts than recommended under Saudi technical regulation and standards for packaged whole dates. Moisture content and insect damage for all studied cultivars fell within Codex standards. Single fruit weight for pitted and unpitted dates was higher than recommended under international standards. Date cultivar had a significant effect on fruit color thus fruit color should be included in Saudi technical regulation and standards for date grading.展开更多
This paper aims to deal with the assessment of axial load capacity for cast in place pile foundations, which are made by the earth drill method, by using the data taken from Standard Penetration Tests (SPTs) and Piezo...This paper aims to deal with the assessment of axial load capacity for cast in place pile foundations, which are made by the earth drill method, by using the data taken from Standard Penetration Tests (SPTs) and Piezocone Penetration Tests (CPTUs). These tests were carried out as part of the investigation program for P.N.G. Terminal-Power Plant, near Semani beach, in Hoxhara marsh, in the western part of Albania. The design of axial load capacity of piles is based on empirical formula using SPT and CPTU values. This study presents the results of axial load capacity analysis of cast in place piles by different analytical calculation methods, which are based on in situ tests results, and also referring to the Building Standard Law of Japan. In the end of our work, differences between calculations methods by using different in situ tests results are shown in tables and graphs.展开更多
The ability of a pavement structure in carrying out its function reduces in line with the increase of traffic load, especially if there are overloaded heavy vehicle passing through the road. This study was done to kno...The ability of a pavement structure in carrying out its function reduces in line with the increase of traffic load, especially if there are overloaded heavy vehicle passing through the road. This study was done to know the effect of overloading vehicles on the road pavement and remaining service life of the pavement. In this study, the service life of pavement due to overloaded vehicles was analyzed using the AASHTO 1993. In Narayanghat-Mugling road the composition of traffic seems to be 83.76% heavy vehicles, 9.18% medium vehicle and 7.05% light vehicle. For the direction of Narayanghat-Mugling, the pavement service life might be reduced by 59.90% due to overloading condition, while for the opposite direction, the service life would not reduced caused by the same factor. The impact of overload conditions on the road pavement showed premature failure;that is, a condition which the damage reduced the life of roads before the design life of the road is reached. From the results, it can be concluded that overloaded vehicles on the road are very influential to the reduction in pavement service life. Therefore, it is expected that road users to comply with existing regulations in the conduct of transportation. As overloading is increasing, it has to be controlled by rules and regulations with penalty to control the overloading. So fines must be associated with intensified enforcement when considered in further strategy. Regular monitoring, inspection and enforcement are the effective ways to control overloading. Use of technology (Automatic overloading information system) may be the effective way to control the overloading.展开更多
In a companion paper [1], an optimization scheme for extended-end-plate Reduced Beam Section (RBS) connections of steel-moment-frames was presented, based on the component method of Eurocode 3, on regression analysis ...In a companion paper [1], an optimization scheme for extended-end-plate Reduced Beam Section (RBS) connections of steel-moment-frames was presented, based on the component method of Eurocode 3, on regression analysis and on principles of Mechanics under monotone loading. European beam and column profiles were utilized, in conjunction with geometric restrictions and constraints of North American and European Standards for prequalified radius-cut RBS. Τhe aforementioned method aimed for an excellent seismic performance, the verification and validation of which is the content of the present study. Using FEM modeling and accounting for the assumptions used in the optimum design, after calibration with existing experimental data, the optimum connections were numerically analyzed under cyclic loading, adopting a well-accepted displacement-based protocol. All optimum solutions exhibited an excellent cyclic response, and met very satisfactorily all the performance criteria for seismic design. Results in terms of hysteretic M-φcurves at three characteristic areas of the connections validate the whole analysis, a fact aiming to assist in incorporation the radius-cut RBS concept in European Steel Design Codes and engineering practice.展开更多
基金financially supported by the Fourth Term of"333 Engineering"Program of Jiangsu Province(Grant No.BRA2011116)Youth Foundation of Jiangsu Province(Grant No.BK2012095)Special Program for Hadal Science and Technology of Shanghai Ocean University(Grant No.HAST-T-2013-01)
文摘Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.
文摘The conformity of Saudi dates cultivars to date standards has not been studied extensively. In this study, microbial loads and physicochemical characteristics of four Saudi date cultivars (Sukkary, Khalas, Sugai and Anbara) were determined. Anbara cultivar had significantly higher mould and yeast counts than recommended under Saudi technical regulation and standards for packaged whole dates. Moisture content and insect damage for all studied cultivars fell within Codex standards. Single fruit weight for pitted and unpitted dates was higher than recommended under international standards. Date cultivar had a significant effect on fruit color thus fruit color should be included in Saudi technical regulation and standards for date grading.
文摘This paper aims to deal with the assessment of axial load capacity for cast in place pile foundations, which are made by the earth drill method, by using the data taken from Standard Penetration Tests (SPTs) and Piezocone Penetration Tests (CPTUs). These tests were carried out as part of the investigation program for P.N.G. Terminal-Power Plant, near Semani beach, in Hoxhara marsh, in the western part of Albania. The design of axial load capacity of piles is based on empirical formula using SPT and CPTU values. This study presents the results of axial load capacity analysis of cast in place piles by different analytical calculation methods, which are based on in situ tests results, and also referring to the Building Standard Law of Japan. In the end of our work, differences between calculations methods by using different in situ tests results are shown in tables and graphs.
文摘The ability of a pavement structure in carrying out its function reduces in line with the increase of traffic load, especially if there are overloaded heavy vehicle passing through the road. This study was done to know the effect of overloading vehicles on the road pavement and remaining service life of the pavement. In this study, the service life of pavement due to overloaded vehicles was analyzed using the AASHTO 1993. In Narayanghat-Mugling road the composition of traffic seems to be 83.76% heavy vehicles, 9.18% medium vehicle and 7.05% light vehicle. For the direction of Narayanghat-Mugling, the pavement service life might be reduced by 59.90% due to overloading condition, while for the opposite direction, the service life would not reduced caused by the same factor. The impact of overload conditions on the road pavement showed premature failure;that is, a condition which the damage reduced the life of roads before the design life of the road is reached. From the results, it can be concluded that overloaded vehicles on the road are very influential to the reduction in pavement service life. Therefore, it is expected that road users to comply with existing regulations in the conduct of transportation. As overloading is increasing, it has to be controlled by rules and regulations with penalty to control the overloading. So fines must be associated with intensified enforcement when considered in further strategy. Regular monitoring, inspection and enforcement are the effective ways to control overloading. Use of technology (Automatic overloading information system) may be the effective way to control the overloading.
文摘In a companion paper [1], an optimization scheme for extended-end-plate Reduced Beam Section (RBS) connections of steel-moment-frames was presented, based on the component method of Eurocode 3, on regression analysis and on principles of Mechanics under monotone loading. European beam and column profiles were utilized, in conjunction with geometric restrictions and constraints of North American and European Standards for prequalified radius-cut RBS. Τhe aforementioned method aimed for an excellent seismic performance, the verification and validation of which is the content of the present study. Using FEM modeling and accounting for the assumptions used in the optimum design, after calibration with existing experimental data, the optimum connections were numerically analyzed under cyclic loading, adopting a well-accepted displacement-based protocol. All optimum solutions exhibited an excellent cyclic response, and met very satisfactorily all the performance criteria for seismic design. Results in terms of hysteretic M-φcurves at three characteristic areas of the connections validate the whole analysis, a fact aiming to assist in incorporation the radius-cut RBS concept in European Steel Design Codes and engineering practice.
