A new kind of composite buffering material was made by filling the voids of honeycomb paperboard with polyurethane. Drop tests were performed to evaluate the dynamic energy absorption capacity of the material. Based o...A new kind of composite buffering material was made by filling the voids of honeycomb paperboard with polyurethane. Drop tests were performed to evaluate the dynamic energy absorption capacity of the material. Based on the tests results, we analyzed the mechanical behaviors of the material under different conditions and obtained the inherent influencing laws of some factors on the material＇s dynamic buffering performance. It was shown that the dynamic buffering performance varied directly with impact velocity, and inversely with the void diameter, thickness and buffeting area of the composite material.展开更多
Plain round bars were commonly used as main bars in the design of RC （reinforced concrete） buildings prior to the 1970s. According to previous research investigating the seismic performance of reinforced concrete me...Plain round bars were commonly used as main bars in the design of RC （reinforced concrete） buildings prior to the 1970s. According to previous research investigating the seismic performance of reinforced concrete members constructed with plain round bars, the strength of those members did not reach the calculated flexural strength due to bond slippage of main bars before yielding. It is important, therefore, to investigate the hysteretic bond mechanisms of plain round bars in concrete. In this research, analytical models were proposed to predict hysteretic bond-slip mechanisms between plain round bar and concrete depending on the results of experiments performed by the authors. In addition, the energy absorption capacity and the equivalent viscous damping factors obtained from the experimental results and analytical models are discussed. As a result of comparisons between the experimental data and the analysis models, good agreements were obtained.展开更多
基金Funded in part by the National Natural Science Foundation of China(No.51008306)
文摘A new kind of composite buffering material was made by filling the voids of honeycomb paperboard with polyurethane. Drop tests were performed to evaluate the dynamic energy absorption capacity of the material. Based on the tests results, we analyzed the mechanical behaviors of the material under different conditions and obtained the inherent influencing laws of some factors on the material＇s dynamic buffering performance. It was shown that the dynamic buffering performance varied directly with impact velocity, and inversely with the void diameter, thickness and buffeting area of the composite material.
文摘Plain round bars were commonly used as main bars in the design of RC （reinforced concrete） buildings prior to the 1970s. According to previous research investigating the seismic performance of reinforced concrete members constructed with plain round bars, the strength of those members did not reach the calculated flexural strength due to bond slippage of main bars before yielding. It is important, therefore, to investigate the hysteretic bond mechanisms of plain round bars in concrete. In this research, analytical models were proposed to predict hysteretic bond-slip mechanisms between plain round bar and concrete depending on the results of experiments performed by the authors. In addition, the energy absorption capacity and the equivalent viscous damping factors obtained from the experimental results and analytical models are discussed. As a result of comparisons between the experimental data and the analysis models, good agreements were obtained.
