Based on an assumption of parabolic bond stress distribution,a simplified model with quartic polynomial function of the relative slip of steel bar and surrounding concrete for reinforced concrete (RC)tensile member wa...Based on an assumption of parabolic bond stress distribution,a simplified model with quartic polynomial function of the relative slip of steel bar and surrounding concrete for reinforced concrete (RC)tensile member was proposed. The post-cracking behavior as well as tension stiffening effect was considered in the new model. The relative slip of bending member could also be determined through the extension of the new model,which could be applied to obtaining the concentrated rotations at certain sections in order to predict the flexural deformation of RC beam. Several examples of four-point bending RC beams were approached to verify the new model,and the predictions of the flexural deflections of RC beams agreed well with experimental results. The new model can be extended to the application of partially corroded RC beam.展开更多
The deformation mechanism during the solidification was analyzed based on the experimental results of the castings. An approximate quadratic differential equation and its discrete model of calculation deflection were ...The deformation mechanism during the solidification was analyzed based on the experimental results of the castings. An approximate quadratic differential equation and its discrete model of calculation deflection were proposed. The model indicates that the key factors leading to the deflection deformation are the thermal bending moment M and the flexural rigidity EJ. The smaller the former and the larger the latter is, the smaller the deflection deformation will be. The experiments are carried out at various technical conditions, and their results appear good agreement with calculation ones. A method was proposed to predict and control the casting deformation.展开更多
Nine PHC piles with partial normal-strength deformed bars were prepared in present study,and cyclic loading tests were implemented to evaluate these piles’seismic performance.The influence of the axial compression ra...Nine PHC piles with partial normal-strength deformed bars were prepared in present study,and cyclic loading tests were implemented to evaluate these piles’seismic performance.The influence of the axial compression ratio and the amount of normal-strength deformed bars on failure modes,crack patterns,strength,stiffness,and ductility were examined.The test findings indicate that the change of axial compression ratio has a noticeable influence on the failure mode of PHC piles.A larger axial compression ratio results in a higher cracking bending resistance,ultimate bending resistance,and initial stiffness,but the propagation heights of flexural cracks decrease as the axial compression ratio increases.Furthermore,increasing the amount of normal-strength deformed bars causes a slight decrease in ductility.Finally,a calculation formula was proposed to predict the flexural capacity of PHC piles with partial normal-strength deformed bars.展开更多
基金National Key Basic Research and Development Program(973Program),China(No.2002CB412709)
文摘Based on an assumption of parabolic bond stress distribution,a simplified model with quartic polynomial function of the relative slip of steel bar and surrounding concrete for reinforced concrete (RC)tensile member was proposed. The post-cracking behavior as well as tension stiffening effect was considered in the new model. The relative slip of bending member could also be determined through the extension of the new model,which could be applied to obtaining the concentrated rotations at certain sections in order to predict the flexural deformation of RC beam. Several examples of four-point bending RC beams were approached to verify the new model,and the predictions of the flexural deflections of RC beams agreed well with experimental results. The new model can be extended to the application of partially corroded RC beam.
文摘The deformation mechanism during the solidification was analyzed based on the experimental results of the castings. An approximate quadratic differential equation and its discrete model of calculation deflection were proposed. The model indicates that the key factors leading to the deflection deformation are the thermal bending moment M and the flexural rigidity EJ. The smaller the former and the larger the latter is, the smaller the deflection deformation will be. The experiments are carried out at various technical conditions, and their results appear good agreement with calculation ones. A method was proposed to predict and control the casting deformation.
基金National Natural Science Foundation of China under Grant No.51578369the Tianjin Science and Technology Major Project under Grant No.17ZXCXSF00080。
文摘Nine PHC piles with partial normal-strength deformed bars were prepared in present study,and cyclic loading tests were implemented to evaluate these piles’seismic performance.The influence of the axial compression ratio and the amount of normal-strength deformed bars on failure modes,crack patterns,strength,stiffness,and ductility were examined.The test findings indicate that the change of axial compression ratio has a noticeable influence on the failure mode of PHC piles.A larger axial compression ratio results in a higher cracking bending resistance,ultimate bending resistance,and initial stiffness,but the propagation heights of flexural cracks decrease as the axial compression ratio increases.Furthermore,increasing the amount of normal-strength deformed bars causes a slight decrease in ductility.Finally,a calculation formula was proposed to predict the flexural capacity of PHC piles with partial normal-strength deformed bars.
