竖向及水平加载下预应力框架塑性角的对比

Comparative Study on Plastic Hinges of Prestressed Concrete Frames Under Vertical or Horizontal Loads

通过单层两跨预应力框架,对竖向及水平加载下的塑性铰出铰模式,控制截面塑性铰所需转动能力以及其所能提供的塑性转动能力等方面进行了对比研究.在研究过程中考虑了相对受压区高度和预应力度影响.研究结果表明,当各塑性铰均具有足够转动能力时,竖向及水平加载下的塑性铰出铰模式存在很大差别.其中竖向加载下,预应力框架梁能达到完全的塑性内力重分布,而水平加载下则不能.此外,随相对受压区高度增加,竖向加载下完成完全塑性内力重分布时所需塑性铰转动能力呈递增趋势;而水平加载下完成最大塑性内力重分布时所需塑性铰转动能力却呈递减趋势.

In With one-storey, two-span prestressed frames, a comparative study is done between under vertical and horizontal loads. The studies include the pattern of the plastic hinges occurring and, the demanded and available rotational capability of the hinges in critical sections. The relative height of compression zone and prestressed degree are considered. The result indicates that there is much difference in the pattern of the plastic hinge occurring when each plastic hinge has enough rotational capability. The beams can finish a full redistribution of internal force under vertical loads, but not under horizontal loads. Moreover, as increasing of the relative height of compression zone, a stronger rotational capability of hinges will be demanded to finish a full redistribution under vertical loads when a weaker rotational capacity will be needed under horizontal loads.