总览

在 1993-1-1: 钢结构设计 (欧洲规范 3) 概述了使用极限状态方法用于建筑物的结构钢构件的设计指南. 极限状态设计需要将因子设计载荷与减少的截面和构件容量进行比较. 这些因素旨在考虑负载条件和材料特性的变化. 对于最终极限状态 (超低硫) 设计要让人满意, 以下关系必须正确:

\(超低硫 \;因素 * 负载≤减少 \;因素 * 容量)

This design guide outlines the procedure for designing a structural steel member in accordance with EN 1993-1-1 使用 在 1993-1-1 钢构件设计 模块.

内容

• 材料特性
  • 制造
  • 钢级
  • 屈服强度
• 栏目分类
  • 压缩元件
  • Classification Ratios
  • Plastic Stress Distribution
  • Elastic Stress Distribution
• 截面电阻
  • 弯曲
  • 剪力
  • 压缩
  • 张力
• Buckling Resistance
  • 弯曲
  • 压缩

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材料特性

制造

在 1993-1-1 为四种类型的结构钢制造提供设计指导:

• 热轧型材: 热轧型材是通过轧机加热和轧制钢坯以达到所需形状而制造的. 示例包括 UB/UC/UBP I 型截面, T 形截面, 通道和角截面.
• 焊接截面: 焊接式 (或捏造的) 型材由多块热轧平板纵向焊接在一起形成钢型材. 定制型材通常采用焊接方式.
• 热加工型材: 热成品型材是通过在轧制之前将钢加热到超过其再结晶温度来生产的，以提高最终产品的强度. 这些截面几乎都是结构空心截面 (右侧/右侧/左侧/右侧).
• 冷弯型材: 冷成型型材是通过在室温下通过轧机压制钢坯来制造的. 冷成型可用于生产结构空心型材和较薄的开口型材. 注意 EN 1993-1-1 仅提供空心冷弯型材的指导.

钢级

欧洲和英国有众多钢种 (优势) 可用于符合 EN 的设计 1993-1-1. 针对不同类型的钢结构制造有多种欧洲材料标准:

• 在 10025: 热轧产品.
• 在 100210: 热成品结构空心型材.
• 在 10219: 冷弯焊接结构空心型材.

热轧型材 (在 10025)

热轧型钢的常用牌号和指示屈服强度概述如下:

热加工结构空心型材 (在 100210)

热成品结构空心型材的常用牌号可用性和指示性屈服强度概述如下:

屈服 & 抗拉强度

材料的屈服强度是发生塑性变形的应力极限. 拉伸强度是材料在失效之前可以承受的最大应力 / 分裂. 型钢的屈服强度和抗拉强度取决于钢种和厚度. 通常，强度随着钢种的增加而增加，但随着钢厚度的增加而降低.

在 1993-1-1 桌子 3.1 提供了一种根据截面的等级和厚度计算其屈服强度和抗拉强度的简化方法. 更详细的材料强度计算可以参考材料相关材料标准. SkyCiv CN 1993-1-1 钢构件设计模块可以 不是 使用这种简化，而是参考相关材料标准进行材料强度计算.

在 SkyCiv EN 中选择一个部分 1993-1-1 钢构件设计

SkyCiv 在 1993-1-1 钢构件设计 工具允许用户从 SkyCiv 数据库中选择标准钢截面或设计完全定制的截面. 程序根据所选钢种自动计算型材翼缘和腹板的屈服强度值. 如果需要，用户还可以采用自定义钢种并手动输入材料属性.

尝试使用 EN 1993-1-1 Steel Design Module

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栏目分类

部分分类是 EN 使用的系统 1993-1-1 在达到其全部塑性能力之前确定截面对局部屈曲的敏感性. 大型细长形状通常比小型细长形状更容易受到局部屈曲的影响, 矮胖的形状. SkyCiv 在 1993-1-1 钢构件设计 工具根据应用的载荷条件自动计算标准和定制钢截面的分类. 欧洲规范 3 有四个部分分类类别:

• 班级 1: 可以形成塑性铰链并产生塑性力矩/轴向阻力的部分, 这意味着整个截面在弯曲和/或压缩下可以达到其屈服强度. 班级 1 sections also have high rotational capacity. 塑料截面属性用于容量计算.
• 班级 2: 能够形成塑性铰链但旋转能力有限的部分. 欧洲规范 3 款待类 1 和班级 2 几乎所有容量计算的部分都类似.
• 班级 3: 其极端压缩纤维可以达到屈服强度的部分, 但在达到塑性力矩阻力之前局部弯曲. 弹性截面属性用于容量计算.
• 班级 4: 在部分截面达到屈服强度之前，将发生局部屈曲. 减少的弹性截面属性用于容量计算.

注意, 班级 4 sections include additional complexity in calculation of section properties / resistance and are not covered in this guide.

压缩元件

截面分类是通过将截面分解为一系列压缩单元并计算它们的长细比来确定的 (净长度与厚度的关系). 元素被分类为:

• 内部的: 抑制两端屈曲 – 即. I 型截面网.
• 杰出: 仅在一端限制屈曲 – 即. I 形截面的法兰.

计算出的长细值与表进行比较 5.2 英语 1993-1-1 来确定他们的班级. 截面的分类取其受压元件最不利的分类. 注意, 截面分类根据截面上的力而变化 (特别变化的轴向力). 每种类型负载的分类方法总结如下.

Classification Ratios

受压缩零件

纯压缩中的元素仅使用下面概述的限制根据其细长度进行分类.

在哪里:

\(ε = \sqrt{\压裂{235}{f_y}}\)

承受弯曲的零件

Internal elements in pure bending are classified based on their slenderness the limits outlined below.

Outstand elements subject to pure bending are classified based on the ratio of compressive and tensile stress under the bending moment value resulting in compressive stress equal to yield stress at the extreme fibre. The method for calculating this ratio is detailed in the section below.

受压缩零件 & 弯曲

Elements subject to combined compression and bending are classified based on their compressive / tensile stress distribution under the applied compression loading. This ratio is represented by the α symbol for plastic stress distribution and ψ symbol for elastic stress distribution.

Plastic Stress Distribution

Formulae for calculating plastic stress ratio (一种) for different shape profiles are provided below.

I-Section Plastic Stress Distribution

T-Section Plastic Stress Distribution

Note minor axis stress distributions for T-Sections are similar to those of an I-section.

Channel Plastic Section Stress Distribution

Note major axis stress distributions for T-Sections are similar to those of an I-section.

RHS Plastic Stress Distribution

Elastic Stress Distribution

Elastic stress distribution calculations are similar for all sections and shapes, due to the linear stress distribution between the extreme fibres. The formula for calculating the minimum stress in a section under applied compression and bending is shown below.

Section Classification in SkyCiv EN 1993-1-1 钢构件设计

的 天空文明一号 1993-1-1 钢构件设计 tool automatically determines the Section Classification of standard and custom sections based on the user-input loading. An example output for a Grade S 275, 430x100x64 Channel with 20kN of compression loading is detailed below.

A single Section Classification value is used for all calculations based on the applied axial force and direction of applied bending moment. If a member has bending moment applied about both axes, the most conservative classification from each direction is adopted. Users can also override the automatic calculation of Section Classification and specify a classification manually.

注意, 条款 5.4.1(3) specifies that singly symmetric sections (such as T-sections and Channels) cannot be designed using plastic analysis when bent about their non-symmetric axis. Hence sections of this nature are automatically assigned Class 3.

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截面电阻

弯曲

Section Bending Resistance

Section bending moment capacity is calculated using EN 1993-1-1 条款 6.2.5.

\(M_{C,路} = W*f_y/γ_{莫0}\)

Where W is the plastic section modulus (w ^_PL) for Class 1 & 2 部分, or the elastic section modulus (w ^_el) for Class 3 部分, F_和 is the yield stress of the material and γ is the partial safety reduction factor.

形状的截面模量是量化形状抗弯强度的几何特性. The plastic section modulus assumes that the entire section reaches its yield strength under bending. 截面的塑性截面模量计算如下:

\(W_{PL} = A_{C} * y_{C} + 一个_{Ť} * y_{Ť} \)

其中A_C 和一个_Ť 是塑性中性轴两侧的面积 (PNA), 和y_C / 和_Ť 是从 PNA 到这些区域质心的距离. 注意, PNA 位置等于对称形状的几何质心位置，但会 不是 等于不对称形状的几何质心位置.

弹性截面模量假设整个截面 (形状) 在弯曲下保持弹性, 即. 截面没有任何部分超过屈服强度 (F_和) 材料的. 截面的弹性截面模量计算如下:

\(W_{el} = frac{一世}{和}\)

其中 I 是面积二阶矩，y 是形状的几何质心. Note for an asymmetric shape, the elastic modulus value used in design is the lesser value for positive and negative bending about that axis.

Calculating Section Bending Resistance in SkyCiv EN 1993-1-1 钢构件设计

Once the relevant Section Classification has been calculated, 该模块计算截面弯矩能力 (检查锚容量) about each principal axis. Results for the same 430x100x64 Channel are shown in the example below.

尝试使用 EN 1993-1-1 Steel Design Module

剪力

Section Shear Resistance

Shear resistance is calculated using EN 1993-1-1 条款 6.2.6. Capacity calculations are dependent on the Section Classification of the steel member. Capacity for Class 1 & 2 sections are calculated based on plastic shear resistance, whereas an elastic shear resistance is used for Class 3 & 4 部分.

Plastic shear resistance is calculated using the formula below:

\(V_{PL,路}=A_v * (f_y / \sqrt{3}) / γ_{莫0}\)

Where Av is the shear area of the section in the direction of applied shear force. For most sections this area is equivalent to the area of the web for major axis direction shear, and the area of the flanges for the other direction. Formulae for calculating shear area are provided in EN 1993-1-1 条款 6.2.6(3).

Elastic shear resistance is calculated using the relationship below, which ensures the shear stress at the critical point of the cross-section is less than the yield stress.

\(τ_{埃德}/(f_y / (\sqrt{3 * γ_{莫0}})) ≤ 1\)

The shear stress at this critical point is calculated as follows:

\(τ_{埃德}=(V_{埃德} * 小号)/(一世 * Ť)\)

其中V_埃德 is the applied shear force, S is the first moment of area, I is the section moment of area and t is the thickness at the critical stress location.

The elastic shear stress formula can then be arranged to represent a resistance value (千牛):

\(V_{el,路} = (一世 * Ť * \sqrt{3})/(小号 * f_y)\)

Shear Buckling

Long, slender webs may buckling under applied shear force before they reach their elastic shear resistance. Webs are susceptible to shear buckling if they satisfy the formula below from EN 1993-1-1 条款 6.2.6(6):

\(H / Ť > 72 * ε/η \)

在哪里 η is a factor usually taken as 1.0. Webs susceptible to shear buckling must be checked in accordance with Section 5 或AND 1993-1-5. 注意, shear capacity in accordance with EN 1993-1-5 is not covered in the SkyCiv EN 1993-1-1 工具, but a warning will be displayed if a section is susceptible to shear buckling.

Impact of Shear Force on Bending & Compression Resistance

High applied shear force can have a negative impact on the moment and axial resistance of a section. In EN 1993-1-1, this impact is captured by reducing the yield strength of the section relative to the magnitude of the applied shear (refer Clause 6.2.8 & 6.2.10). When the section shear force is 少于 half its plastic shear resistance in that direction, this impact can be neglected. If the applied shear is greater than this value, the reduced yield strength is calculated as follows:

\(F_{和,路} = (1 -r) * f_y \)

在哪里:

\(ρ = (2 * V_{埃德} / V_{PL,路} – 1)^2\)

的 天空文明一号 1993-1-1 钢构件设计 module automatically calculates any reduction in yield strength due to high applied shear force and uses this reduced value in section bending and compression resistance calculations. 注意, this reduction only applies for the section resistance of a member, not the buckling resistance.

Calculating Shear Resistance in SkyCiv EN 1993-1-1 钢构件设计

的 天空文明一号 1993-1-1 钢构件设计 tool calculates the shear capacity of a section in both principal axis directions. Results from the shear resistance calculations for a 254×102 UB 28 详细如下.

压缩

Section Compression Resistance

在 1993-1-1 条款 6.2.4 计算压缩能力 (ñ_C) of a concentrically loaded Class 1,2 要么 3 section as follows:

\(N_{C,路} = A*f_y / γ_{莫0}\)

Where A is the gross area of the cross section and f_和 是截面的屈服强度.

Calculating Section Compression Resistance in SkyCiv EN 1993-1-1 钢构件设计

的 天空文明一号 1993-1-1 钢构件设计 tool calculates the section compression resistance (ñ_C,路) for standard European sections and custom user-defined sections. Results from the section compression resistance calculations for a 254×102 UB 28 详细如下.

张力

Section Tension Resistance

在 1993-1-1 条款 6.2.3 计算受拉杆件的承载力 (Nt) to be the lesser of the plastic tension resistance and ultimate tension resistance:

\(N_{Ť,路} = min(A*f_{和}/γ_{莫0} \; ,\; 0.9*一个_{ñ}*f_u /γ_{钢底板设计欧洲规范})\)

Where A is the gross area of the section, 一个_ñ 是横截面的净面积 (总面积，不包括穿透/孔洞), F_和 是个 屈服强度 该部分的, F_ü 是个 拉伸 (最终的) strength of the section.

Calculating Tension Resistance in SkyCiv EN 1993-1-1 钢构件设计

的 天空文明一号 1993-1-1 钢构件设计 module assumes no significant holes are present in the section, 因此A_ñ 被视为等于 A. Results from the section tension resistance calculations for a 254×102 UB 28 详细如下.

 

尝试使用 EN 1993-1-1 Steel Design Module

弯曲 & 轴向力

When a section has applied axial tension or compression force, the effect of this force on the section bending moment resistance should be accounted for. The method for assessing this effect outlined in EN 1993-1-1 条款 6.2.9 varies for Class 1 & 2 和班级 3 部分.

班级 1 & 2 栏目

Combined bending and axial force is assessed for Plastic sections by reducing the plastic moment resistance in each direction by an amount proportional to the axial force. This reduced moment resistance is referred to by the symbol M_ñ,路. Calculation of M_ñ,路 varies depending on the section shape and is outlined in EN 1993-1-1 条款 6.2.9.1. Once reduced moment resistance is calculated, the following criterion is used for assessing combined bending and axial resistance:

\( (M_{和,埃德} / M_{Ny,路})^α + (M_{与,埃德} / M_{Nz,路})^ β ≤ 1\)

在哪里 α and β are constants that vary with the section shape – refer EN 1993-1-1 条款 6.2.9.1.

班级 3 栏目

Combined bending and axial force in Elastic sections is instead assessed using a general elastic stress formula detailed below:

\( N_{埃德} / N_{C,路} + M_{与,埃德} / M_{cz,路} + M_{和,埃德} / M_{cy,路} ≤ 1\)

Note any reduction in yield strength required due to applied shear force should be used in calculation of the section resistance values in the formulae above.

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Buckling Resistance

弯曲

Lateral Torsional Buckling Resistance

Long, unrestrained steel members can fail in lateral-torsional buckling prior to attaining their section bending moment resistance. Lateral torsional buckling occurs when the section rotates away from its major axis towards its minor axis, meaning moment resistance in the direction of applied bending is reduced. Guidance for calculating member lateral-torsional buckling resistance is provided in EN 1993-1-1 条款 6.3.2.

Lateral-torsional buckling resistance is calculated using the below formula:

\(M_{b,路} = χ_{LT}*W*f_y/ γ_{M1}\)

Where W is the plastic section modulus (w ^_PL) for Class 1 & 2 部分, or elastic section modulus (w ^_el) for Class 3 部分. χ_LT is a reduction factor for lateral-torsional buckling, guidance for calculating this factor is provided in EN 1993-1-1 条款 6.3.2.2 和 6.3.2.3.

Compression Flange

Members fail in lateral-torsional buckling when the compression flange rotates and displaces laterally. If the compression flange of a member is sufficiently restrained, it will not be susceptible to lateral torsional buckling (refer EN 1993-1-1 条款 6.3.2.1(2)). Compression flange locations for standard sections under vertical loading are shown below.

圆形空心型材 (CHS) 和方形空心截面 (SHS) 不易受到横向扭转屈曲的影响, as they have equal section moment resistance about both axes (meaning lateral displacement and rotation don’t affect the member bending resistance).

Minor Axis Bending Buckling Resistance

The bending capacity for a member bent about its minor axis is equal to the minor axis section resistance about that axis. The minor axis section capacity is the minimum capacity a section can achieve about any axis, 因此该构件不能从该轴旋转到不利的方向.

Calculating Member Bending Resistance in EN 1993-1-1 钢构件设计

的 天空文明一号 1993-1-1 钢构件设计 tool calculates carries out lateral-torsional resistance calculations in accordance with EN 1993-1-1 条款 6.3.2.2 和条款 6.3.2.3, depending on the section shape and applied National Annex. Users also have the option to specify a member as having “Continuous Torsional Restraint” which will automatically skip all lateral-torsional buckling checks. Lateral-torsional buckling resistance calculations for a 5000mm long 254×102 UB 28 详细如下.

尝试使用 EN 1993-1-1 Steel Design Module

压缩

Flexural Buckling Resistance

The compression buckling resistance of a member is also affected by its length and lateral rigidity. 无拘无束, 较长的构件可能会因截面前的弯曲屈曲而失效 (壁球) 容量已达到. 在 1993-1-1 条款 6.3.1.3 provides guidance on calculating member flexural buckling resistance for Class 1, 2 & 3 交叉区域:

\(N_{b,路} = χ*A*f_y/ γ_{M1}\)

在哪里 χ is a reduction factor for flexural buckling. Guidance for calculating this factor is provided in EN 1993-1-1 条款 6.3.1.3. Flexural capacity must be checked about both axes to find the governing value for the member.

Calculating Flexural Buckling Resistance in EN 1993-1-1 钢构件设计

的 天空文明一号 1993-1-1 钢构件设计 tool calculates flexural buckling resistance about both principal axes based on restraint lengths and effective length factors specified by the user. Flexural buckling resistance of a 254×102 UB 28 with an unrestrained length of 6000mm and 5000mm in the Z and Y axis (分别) 详细如下.

Torsional-Flexural Buckling Resistance

Open cross-sections are also susceptible to torsional-flexural buckling, which can be less than the member resistance to flexural buckling. 圆形空心型材 (CHS) 和方形空心截面 (SHS) members are not susceptible to torsional-flexural buckling. 在 1993-1-1 条款 6.3.1.4 provides guidance on calculating member torsional-flexural buckling resistance:

\(N_{bT,路} = χ_T*A*f_y/ γ_{M1}\)

在哪里 χ_LT is a reduction factor for torsional-flexural buckling. Guidance for calculating this factor is provided in EN 1993-1-1 条款 6.3.1.3. Flexural capacity must be checked about both axes to find the governing value for the member.

Calculating Torsional-Flexural Buckling Resistance in EN 1993-1-1 钢构件设计

的 天空文明一号 1993-1-1 Steel Member Design tool calculates torsional-flexural buckling resistance for applicable open and closed sections in accordance with EN 1993-1-1 条款 6.3.1.4 based on compression restraint length in the major axis as specified by the user. Torsional-flexural buckling resistance of a 254×102 UB 28 with an unrestrained length of 6000mm are detailed below.

尝试使用 EN 1993-1-1 Steel Design Module