短悬臂和偏心铰接连接
Short Corbels and Eccentric Hinged Connections
SAP2000和ETABS为用户提供了几种建模解决方案,增加了模型的价值,使其更接近真实结构。
SAP2000 and ETABS offer users several modeling solutions that add value to the model, making it closer to real structures.
在这个例子中,我们将展示两个工具,允许建模特殊的支撑情况,如梁在短悬臂上的支撑。
In this example, we will present two tools that allow modeling special support situations, such as beam supports on short corbels.
在建模这种类型的交互时,主要关注的是确保梁只将垂直荷载传递给悬臂。在模型中指示荷载传递到柱轴线的位置或距离也很重要,以便将偏心效应转换为内力。
One of the main concerns in modeling this type of interaction is ensuring that the beam supports on the corbel, transmitting only vertical loads. It will also be important to indicate in the model the position or distance to the column axis where the load transfer occurs, so that the effect of this eccentricity translates into internal forces.
适用的程序
Applicable Programs
- SAP2000
- ETABS
功能
Functionalities
- Output Station
- Frame End Length Offsets
- Frame Releases and Partial Fixity 框架释放和部分固定
- rigid zone factor
定义一个具有50x50(cm)柱和50x75(cm)梁的混凝土框架。默认情况下,程序将元素放置在轴线上,导致它们重叠,但在大多数情况下,这种效应对建模并不重要。
Definition of a concrete frame with 50x50 (cm) columns and 50x75 (cm) beams. By default, the program introduces the elements to the axis, resulting in their overlap, however, this effect is not relevant for modeling in most situations.
在这种情况下,由于我们要建模梁在短悬臂上的支撑,我们必须定义相对于柱轴线的偏心。选项User Defined Length Offset at End-I和End-J分别指梁的起始节点(I节点)和末端节点(J节点)。Rigid Zone Factor用于指示先前定义的长度中在弯曲和剪切下表现为无限刚度的部分（刚域）的百分比。在这种情况下,由于我们将End Length Offsets与Frame Releases结合使用,无论输入什么值,该长度都将是无限刚度的,因此该因子失去了作用。
In this case, as we want to model a beam support on a short corbel, we have to define the eccentricity relative to the column axis. The option User Defined Length Offset at End-I and End-J refers, respectively, to the initial node (node I) and final node (node J) of the beam. The Rigid Zone Factor serves to indicate the percentage of the previously defined length with infinitely rigid behavior in bending and shear. In this case, as we are going to combine End Length Offsets with Frame Releases, this factor loses its function, because the length will be infinitely rigid regardless of the value entered.
在这个阶段,我们将通过Assign Frame Releases选项在梁端引入弯矩释放。
At this stage, we will introduce moment releases at the ends of the beam through the Assign Frame Releases option.
这是施加结构自重后的结果。结果与预期一致,即跨中有弯矩的简支梁和由于偏心而在柱中产生的弯矩。
This is the result of applying the self-weight of the structure. The results are as expected, that is, a simply supported beam with moments at the midspan and moments in the columns due to the eccentricity.
以下是这种情况下节点平衡的值。
The following are the values of the nodal equilibrium for this type of situation.
