Implementation of M-PFI method in design of steel plate walls

To demonstrate implementation of the modified-plate frame interaction (M-PFI) method in the design of a steel plate wall (SPW) system, three SPWs of different heights were designed for this paper using the M-PFI method. Evaluation of the M-PFI design methodology was performed using the finite element (FE) method to analyze each of the three SPWs under a pushover load to determine its load displacement diagram. FE results were then compared with M-PFI model results. Good agreement was observed for stiffness and strength of the SPW models obtained from both the M-PFI and FE methods. The FE method was used not only to evaluate the three SPW designs, but also to investigate the effects of beam size and material hardening on SPW design. This paper also presents a step-by-step M-PFI design procedure and a simplified flow chart to better illustrate the design process.     

蟒河口水库坝址岩体结构面直剪试验研究

岩体结构面的原位试验及其结果研究分析为设计部门提供更为可靠的资料.同时也为水利枢虹的设计,施工提供依据.本文在对蟒河口水库埂址岩体结构面进行直剪试验的基础上,分析岩体沿结构面的破坏机理,统计分析得到了抗剪断强度、残余抗剪强度.为水库大坝设计提供了可靠资料.     

多孔钢板在双轴受压与边缘剪力荷载共同作用下的极限强度

作为作者系列研究成果[Paik J K．Ultimate strength of perforated steel plates under edge shear loading．Thin-Walled Structures，2007，45：301-6，Paik J K．Ultimate strength of perforated steel plates under axial compressive loading along short edges．Ships Offshore Struct，2007，2（3）：（inpress）]的终结篇，与前期论文在边缘剪力或单轴压力荷载方面进行了对比，目的是研究双轴受压和边缘剪力作用下多孔钢板的极限强度特点，这是船舶和船舶型海洋结构在货物和水压作用下的一个典型受力模式。板的约束考虑为四边简支，中心区域为圆形孔。一系列ANSYS非线性有限元分析中考虑了不同的板尺寸（厚度）。在有限元分析基础上，推导出组合荷载下多孔板的极限强度交互关系公式，可用于可靠性分析或规范中极限强度的预测。     

高层建筑结构施工监理的体会

通过多年对高层建筑结构施工监理的实践,就如何确保高层建筑的建设质量作一探讨,同时提出了高层建筑结构施工监理应注意的事项,为施工监理人员提供了参考借鉴。     

宅间——画家住宅

时间与空间的重叠关系是否可以解结并重结一种具体空间使用关系。“画家住宅”是继“作者住宅”之后对园林开放性、流动性、瞬间性视角变换的诠释。     

预应力对混凝土宽箱梁桥剪力滞的影响分析

目前对多室宽箱梁剪滞效应的研究尚少,其中更有必要研究预应力的影响。通过对一座典型的五跨预应力混凝土宽箱梁桥进行三维有限元分析,考虑了预应力束的空间作用效应,得出该类型宽箱梁桥在有无预应力作用下其剪力滞效应的比较,其结果可供同类工程参考。     

Solids motion of calcium carbonate particles in a high shear mixer granulator: A comparison between dry and wet conditions

An experimental study has been carried out on the solids motion in a conical frustum-shaped vertical high shear mixer granulator by using the positron emission particle tracking (PEPT) technique. The mixer granulator has a vertical shaft, to which four sets of impellers are attached at different elevations. The shaft is operated at 3.9 Hz, 4.9 Hz and 5.8 Hz, which corresponded to the top impeller tip speed of 2.8, 3.5 and 4.1 m/s. The motion of calcium carbonate particles with and without a liquid binder is evaluated. Particles are observed to circulate in both the horizontal and vertical directions. The macroscopic solids circulation in the vertical direction reduces after adding the binder. There is a dominant solids motion in the tangential direction under both the dry and wet conditions with the maximum tangential velocity of 2.2 to 12.6 times that of the maximum axial and radial velocities. No obvious change is observed in the average axial and radial velocities when the impeller speed is changed under both dry and wet conditions, while the ratio of the maximum tangential velocity to the tip speed decreases with increasing impeller speed, suggesting a velocity-dependent behaviour. The three velocity components decrease in the magnitude after adding the binder at all tested agitation speeds except for the tangential velocity at a shaft speed of 3.9 Hz. The main difference between the dry and wet operations is that the decrease of tangential velocity in the near-wall zone under the dry condition is not observed under the wet condition.     

非均质混杂叠层梁的分层剪切理论

本文研究了正交各向异性混杂叠层梁的应力与变形计算.叠层梁是由几层弹性性质明显不同的非均质子层梁组成.对每一子层梁应用剪切理论,并假设相邻子层梁的交界面是理想连接.文中导出了关于子层梁剪切转角ψ_i的二阶常微分方程组.求解微分方程组可得到叠层梁应力与位移关于剪切转角的ψ_i解析表达式.叠层梁组分材料中任一点应力可按有效模量理论和整体——局部方法[3]求得.     

Pull-out work of steel fibers from cementitious composites: Analytical investigation

The main objective of this study is to provide a parametric evaluation of the pull-out work of smooth steel fibers embedded in cementitious matrices. The various parameters controlling the behavior of the bond stress versus slip relationship are analyzed; their effects on the entire pull-out load versus slip response and the corresponding pull-out energy up to full debonding and/or up to total pull-out are investigated. Also discussed are the effects of the fiber geometric parameters such as fiber diameter, length, and aspect ratio. Finally, a brief section addresses the relation between pull-out work and the critical strain energy release rate G_c, a fracture mechanics variable, which can be calculated if the P-Δ curve is known.