> For the complete documentation index, see [llms.txt](https://manual-1-3.karamba3d.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://manual-1-3.karamba3d.com/chinese_1_3_3/3-in-depth-component-reference/3.3-cross-section/3.3.8-modify-cross-section.md).

# 3.3.8: 编辑断面 (Modify Cross Section) 🔷

在Karamba3D中，断面属性可分为四种类型：

|                       |                           |
| --------------------- | ------------------------- |
| **“General（常规）”**     | 用于设置名称、系列、颜色、材料和元素标识符的参数。 |
| **“Geometry（几何形状）”**  | 确定断面尺寸和偏心率的属性             |
| **“Deformation（变形）”** | 这些参数影响结构的弹性行为             |
| **“Resistance（阻力）”**  | 断面设计程序使用的属性，其目的是确定承载能力。   |

**“Modify Cross Section（编辑断面）”** 运算器允许修改这些属性。该运算器存在两种操作模式：

**Flow through（流经）：**当断面作为输入时，默认情况下，其左侧结果是相同的断面。用户仅需修改那些输入值的数据。

**Agent（代理）：**可通过**“Elem-Ids”**输入选择要修改的断面。可以使用正则表达式。生成的断面代理为**“Cross Section（断面）”**类型，在接入**“Assemble（模型构建）”**运算器时会被激活。

![图3.3.8.1：“ModifyCroSec（编辑断面）”](/files/-M9XuSowBqt_zXq5DlXp)

图3.3.8.1显示了均匀荷载下简支梁的定义。用于计算此类系统最大位移的理论公式通常会忽略剪切变形的影响。为确保断面在剪切时接近刚性，使用**“Modify Cross Section （编辑断面）”** 运算器将剪切面积$$A\_z$$设置为较大的值。图3.3.8.1“ModifyCroSec（编辑断面）”运算器可用于在断面局部z轴方向施加剪力刚度。如图所示，计算出的最大位移与无剪力效应的公式结果一致。

如果断面的高度或厚度随着变形或阻力参数的变化而变化，检测会由上至下进行：首先，所有参数均根据新的断面尺寸进行更新，其次，通过覆写新的参数值，可实现阻力特性变形。运算器底部的下拉列表允许在梁断面和壳体断面之间进行切换。


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