The steel reinforced plastic pipe is a kind of green environmental protection pipelines with double-sides corrosionresisting and better withstanding to medium working pressure.The structure and technical process of th...The steel reinforced plastic pipe is a kind of green environmental protection pipelines with double-sides corrosionresisting and better withstanding to medium working pressure.The structure and technical process of this pipe are described briefly in this paper,and the finite element analysis has been done for the sake of understanding the distributions of stress and displacement inside this pipe under hydrostatic pressure.The analysis results are very important for safety application of the steel reinforced plastic pipe.展开更多
The steel reinforced plastic pipe is a new kind of pressure pipe. It is made up with steelwires and plastic. Because reinforced skeleton of the steel wire increase the complexityof plastic flow during the extrusion ph...The steel reinforced plastic pipe is a new kind of pressure pipe. It is made up with steelwires and plastic. Because reinforced skeleton of the steel wire increase the complexityof plastic flow during the extrusion phase, the traditional design criteria of extrusiondie is not suitable. The study on extrusion die of the kind of pipe is very importantstep in produce development. Using finite element (FE) method in this paper, theflow rule of molten plastic inside the die has been predicted and a groap of optimalstructural parameters was obtained. These results are helpful for reducing the designcycle and improve the quality of the final product.展开更多
The fiberglass reinforced plastic （FRP） pipelines have been used widely in oil-gas gathering and transportation. The defects of FRP pipelines would increase with the extension of service time. However, it is very di...The fiberglass reinforced plastic （FRP） pipelines have been used widely in oil-gas gathering and transportation. The defects of FRP pipelines would increase with the extension of service time. However, it is very difficult to detect the defects of FRP pipelines on-spot quickly. In this paper, a new method detecting defects for FRP pipes has been provided based on the NMR. The proton density distributions have been obtained at different depth of FRP components using single-side NMR. The experimental results show that there is a significant change of proton density distribution at the location of defects. And, these results would be useful for defects inspection of composite material component.展开更多
A three-dimensional finite element program for thermal analysis of hydration heat in concrete structures with a plastic pipe cooling system is introduced in this paper. The program was applied to simulation of the tem...A three-dimensional finite element program for thermal analysis of hydration heat in concrete structures with a plastic pipe cooling system is introduced in this paper. The program was applied to simulation of the temperature and stress field of the Cao＇e Sluice during the construction period. From the calculated results, we can find that the temperaiure and stress of concrete cooled with plastic pipes are much lower than those of concrete without pipes. Moreover, plastic pipes could not be corroded by seawater. That is to say, a good effect of temperature control and cracking prevention can be achieved, which provides a useful reference for other similar nearshore concrete projects.展开更多
The modulus of soil reaction,representing the stiffness of a soil surrounding pipes,is a critical parameter in the design of buried flexible pipes.This study conducted plate loading tests on corrugated polyvinyl chlor...The modulus of soil reaction,representing the stiffness of a soil surrounding pipes,is a critical parameter in the design of buried flexible pipes.This study conducted plate loading tests on corrugated polyvinyl chloride,smooth polyvinyl chloride,and high-density polyethylene pipes buried in lightweight cellular concrete(LCC)backfills at densities of 400,475,550,and 650 kg/m^(3)to investigate the pipe deformation behavior and moduli of soil reaction.In addition,this study examined the effects of the narrow trench condition on the pipe deformation and modulus of soil reaction.In these tests,the vertical and horizontal diameter changes of pipes under the vertical pressures applied through a hydraulic jack were measured.Test results reveal that the average moduli of soil reaction of plastic pipes within a wide trench backfilled by the LCCs at densities of 400,475,550,and 650 kg/m^(3)were back-calculated as 66,99,133,and 205 MPa,respectively,using the modified Iowa formula.Furthermore,the back-calculated moduli of soil reaction for LCCs exhibited linear relationships with their densities and unconfined compressive strengths and were higher than the recommended values for the commonly used soil backfills.Based on the vertical deformation criterion of 5%pipe diameter,the ultimate bearing capacities of flexible pipes buried in wide LCCs at densities of 475,550,and 650 kg/m^(3)exceeded 500 kPa.The LCC with a narrow trench exhibited a lower modulus of soil reaction and ultimate bearing capacity but a larger pipe diameter change.展开更多
文摘The steel reinforced plastic pipe is a kind of green environmental protection pipelines with double-sides corrosionresisting and better withstanding to medium working pressure.The structure and technical process of this pipe are described briefly in this paper,and the finite element analysis has been done for the sake of understanding the distributions of stress and displacement inside this pipe under hydrostatic pressure.The analysis results are very important for safety application of the steel reinforced plastic pipe.
文摘The steel reinforced plastic pipe is a new kind of pressure pipe. It is made up with steelwires and plastic. Because reinforced skeleton of the steel wire increase the complexityof plastic flow during the extrusion phase, the traditional design criteria of extrusiondie is not suitable. The study on extrusion die of the kind of pipe is very importantstep in produce development. Using finite element (FE) method in this paper, theflow rule of molten plastic inside the die has been predicted and a groap of optimalstructural parameters was obtained. These results are helpful for reducing the designcycle and improve the quality of the final product.
文摘The fiberglass reinforced plastic （FRP） pipelines have been used widely in oil-gas gathering and transportation. The defects of FRP pipelines would increase with the extension of service time. However, it is very difficult to detect the defects of FRP pipelines on-spot quickly. In this paper, a new method detecting defects for FRP pipes has been provided based on the NMR. The proton density distributions have been obtained at different depth of FRP components using single-side NMR. The experimental results show that there is a significant change of proton density distribution at the location of defects. And, these results would be useful for defects inspection of composite material component.
基金supported by the National Natural Science Foundation of China (Grant No. 50779010)
文摘A three-dimensional finite element program for thermal analysis of hydration heat in concrete structures with a plastic pipe cooling system is introduced in this paper. The program was applied to simulation of the temperature and stress field of the Cao＇e Sluice during the construction period. From the calculated results, we can find that the temperaiure and stress of concrete cooled with plastic pipes are much lower than those of concrete without pipes. Moreover, plastic pipes could not be corroded by seawater. That is to say, a good effect of temperature control and cracking prevention can be achieved, which provides a useful reference for other similar nearshore concrete projects.
基金supported by the CEMATRIX Corp.The authors would like to thank technicians David Woody,Kent Dye,and Meyer Carey in the Civil,Environmental,&Architectural Engineering Department at the University of Kansas,for their great assistance in modifying and calibrating the test devices used in this studyThe authors also would like to appreciate Ph.D.student Alsharari Turki from the University of Kansas and formerly visiting student Hsin-Ming Wu at the University of Kansas,and Albert Fang from CEMATRIX for their great help on the model tests.Josh Beakley at the American Concrete Pipe Association provided valuable comments and suggestions for the data analysis of soil reaction modulus.
文摘The modulus of soil reaction,representing the stiffness of a soil surrounding pipes,is a critical parameter in the design of buried flexible pipes.This study conducted plate loading tests on corrugated polyvinyl chloride,smooth polyvinyl chloride,and high-density polyethylene pipes buried in lightweight cellular concrete(LCC)backfills at densities of 400,475,550,and 650 kg/m^(3)to investigate the pipe deformation behavior and moduli of soil reaction.In addition,this study examined the effects of the narrow trench condition on the pipe deformation and modulus of soil reaction.In these tests,the vertical and horizontal diameter changes of pipes under the vertical pressures applied through a hydraulic jack were measured.Test results reveal that the average moduli of soil reaction of plastic pipes within a wide trench backfilled by the LCCs at densities of 400,475,550,and 650 kg/m^(3)were back-calculated as 66,99,133,and 205 MPa,respectively,using the modified Iowa formula.Furthermore,the back-calculated moduli of soil reaction for LCCs exhibited linear relationships with their densities and unconfined compressive strengths and were higher than the recommended values for the commonly used soil backfills.Based on the vertical deformation criterion of 5%pipe diameter,the ultimate bearing capacities of flexible pipes buried in wide LCCs at densities of 475,550,and 650 kg/m^(3)exceeded 500 kPa.The LCC with a narrow trench exhibited a lower modulus of soil reaction and ultimate bearing capacity but a larger pipe diameter change.
