如何使用 Python 和 Viktor 创建钢底板设计 Web 应用程序

介绍

钢底板放置在钢柱下方，以将设计力安全地传递至地基。

当钢柱承受较大荷载且截面较小时，直接将荷载施加到基础上可能会导致冲孔破坏。因此，在柱子下方使用底板将荷载分散到更大的面积上至关重要。

本文提供了使用 Python 创建底板设计应用程序的指南，利用以 CSV 格式存储的钢材几何属性。

该应用程序将帮助工程师轻松确定所需的底板面积、厚度、混凝土承载强度和额外宽度。

此外，通过利用 Viktor SDK，我们可以无缝地将我们的 Python 实现转换为 Web 应用程序。

此 SDK 提供了在 3D 视图中可视化我们的结构的功能。让我们立即开始行动吧！

底板设计的基本原则

底板设计使用等效 T 型短管法来计算轴向力，其中计算 T 型短管在压缩状态下的“有效面积”，并评估 T 型短管在拉伸状态下的底板弯曲。允许水平主要和/或次要剪切，但不允许弯矩，即铰接底座设计。

我们首先计算的是支撑混凝土的承载强度，fjd。

底板底面与灌浆空间内的垫层材料之间的设计承载强度 fjd 定义为：

fjd = βj * α * fcd

在哪里

βj = 地基接缝材料系数 = (2/3)

α = 表示基础内集中力扩散的系数

fcd = 设计值混凝土抗压强度 = αcc * fck / ɣc

αcc = 长期效应系数

fck = 混凝土特征圆柱强度

ɣc = 混凝土分项安全系数

第二步是计算所需底板面积，其公式如下：

Areq = Ned / fjd

其中，Ned为钢柱的极限荷载。

第三步，计算有效面积的悬臂突出量c：

C 使用以下公式计算：

Aeff = 4 *（c**2）+ Pcol * c + Acol

因此，你解出了 c。

最后，我们计算底板的厚度 tp：

tp = c * (3 * fjd * Ym0 / _page_fy)**0.50

底板设计工作流程的 Python 实现

# Partial factor of resistance of cross-sections whatever the class is as per EN 1993-1-1. Ym0 = 1.0 # Compute foundation bearing strength which is typically concrete #βj is the foundation joint material coefficient, typically taken as 0.67 as per clause 6.2.5(7) in EN 1993-1-8. beta_j=0.67 #α is a coefficient of diffusion of the vertical load being applied to the foundation. Conservatively this can be taken as 1.5 alpha= 1.5 # αcc is the coefficient that allows for long-term effects on the compressive strength of concrete vs applied actions. Taken as 0.85 in the UK National Annex -> on page # Define alpha_cc # Define gamma_c # define fck # γc is the partial factor of safety of concrete. Taken as 1.5 in the UK National Annex -> on page fjd = beta_j*alpha* (alpha_cc*fck )/gamma_c # Compute the area of the baseplate required Areq = (Ned *1000)/ fjd #Ned is the Ultimate load def calculate_c(Pcol, Acol, Areq): # """ # This function calculates the value of c for the given equation: # Areq = 4 * c^2 + P_col * c + A_col # Args: # Perimeter_of_section: Perimeter of the column section (mm) # Area_of_section: Area of the column section (mm²) # Areq: Required area of the baseplate (mm²) # Returns: # The value of c (mm) # """ a = 4 b = Pcol c = Acol-Areq # Assuming Areq is already calculated discriminant = b**2 - 4 * a * c c1 = (-b + (discriminant)**0.5) / (2 * a) c2 = (-b - (discriminant)**0.5) / (2 * a) return max(c1, c2) c = calculate_c(Pcol,Acol,Areq) # Compute the thickness of the baseplate (tp) tp = c * (3 * fjd* Ym0 / _page_fy)**0.50

最后，将 Python 代码转换为用于底板设计的 Web 应用程序

输入

我的最终应用程序将需要输入功能，用户可以指定以下参数：

这是使用 Viktor SDK 中的参数化类实现的。

 class Parametrization(ViktorParametrization): input = Tab("Input") input.profile_type = OptionField( "Profile type", options=["IPE", "HEA", "HEB"], default="IPE", variant="radio-inline", flex=80, ) input.nl1 = LineBreak() input.profile = AutocompleteField( "Profile", options=get_profile_types, default="IPE240", description="The source of profile properties can be found [here](https://eurocodeapplied.com/design/en1993/ipe-hea-heb-hem-design-properties)", ) # input.steel_class = OptionField( # "Steel class", options=["S235", "S275", "S355"], default="S235" # ) input.fck = NumberField('Fck', default=25, suffix="MPa") input.Design_load = NumberField('Design_load', default=1000, suffix="KN") input.acc = NumberField('Concrete coeff(acc)', default=0.85) input.yc = NumberField('Partial factor of safety for concrete', default=1.5) input.steel_class = NumberField('steel_class', default=255, suffix="MPa")

输出

计算完成后，使用Viktor SDK中的数据视图方法向用户显示计算结果。

 @DataView("Output", duration_guess=1) def Compute_output(self, params: Munch, **kwargs): Ym0, beta_j, alpha, fjd, Areq, c, tp = self.calculate_plate_geom(params) data = DataGroup( DataItem("ultimate load ", params.input.Design_load, suffix="KN"), DataItem("beta_j", 0.67), DataItem("alpha", 1.5), DataItem("Bearing capacity of concrete support(fjd) ", round(fjd), suffix="MPa"), DataItem("Areq ", round(Areq), suffix="mm2"), DataItem(" c", round(c), suffix="mm"), DataItem("Thickness of plate", round(tp), suffix="mm"), ) return DataResult(data)

在哪里：

混凝土承载力(Fjd)

所需钢材面积(Areq)

底板附加突出部分(c)

底板厚度

最后，创建了钢柱、底板和支撑混凝土基础的三维模型。

在用@GeometryView修饰的控制器类内部定义了一个get_3dview方法。

get_3dview方法定义了创建3D模型的逻辑，最终返回包含创建的钢柱、底板和混凝土支撑的GeometryResult对象。

该逻辑包含在下面的代码中：

 @GeometryView("3D baseplate View", duration_guess=1) def get_3dView(self, params: Munch, **kwargs): """Create geometry for column, base-plate and add a concrete slab underneath""" Ym0, beta_j, alpha, fjd, Areq, c, tp = self.calculate_plate_geom(params) concrete_thickness = 15 * tp steel = Material(color=Color(95, 158, 240), metalness=1) concrete = Material(metalness=0, roughness=1, opacity=0.6) h = self.get_profile_property(params.input.profile_type, params.input.profile, "Depth") b = self.get_profile_property(params.input.profile_type, params.input.profile, "Width") tw = self.get_profile_property(params.input.profile_type, params.input.profile, "Web thickness") tf = self.get_profile_property(params.input.profile_type, params.input.profile, "Flange thickness") r = self.get_profile_property(params.input.profile_type, params.input.profile, "Root radius") beam_profile = self.get_beam_profile(h, b, tw, tf, r) beam = Extrusion(beam_profile, Line(Point(0, 0, tp), Point(0, 0, 3 * h)), material=steel) base_plate = SquareBeam(sqrt(Areq), sqrt(Areq), tp, material=steel) # TODO: This area doesn't seem sufficient for large column sizes base_plate.translate((0, 0, tp / 2)) concrete_plate = SquareBeam(6 * h, 6 * h, concrete_thickness, material=concrete) concrete_plate.translate((0, 0, -concrete_thickness / 2)) return GeometryResult([beam, base_plate, concrete_plate]) 

完整代码如下：

 from math import sqrt # import plotly.express as px from pathlib import Path from typing import List import numpy as np import pandas as pd from munch import Munch from viktor import ViktorController, Color from viktor.geometry import Point, Extrusion, Line, Material, SquareBeam from viktor.parametrization import ( ViktorParametrization, OptionField, Text, Tab, AutocompleteField, LineBreak, NumberField ) # from viktor.external.spreadsheet import SpreadsheetCalculation, SpreadsheetCalculationInput from viktor.views import DataGroup, DataItem, DataResult, DataView, GeometryView, GeometryResult def get_profile_types(params: Munch, **kwargs): try: file_path = ( Path(__file__).parent / "profiles" / f"steel-profiles-{params.input.profile_type}.csv" ) df = pd.read_csv(file_path, header=[2], skiprows=[3, 4, 5]) return df["Profile"].values.tolist() except FileNotFoundError: return ["IPE80", "IPE100", "HEA100", "HEA120", "HEB100", "HEB120"] def calculate_c(Pcol, Acol, Areq): # """ # This function calculates the value of c for the given equation: # Areq = 4 * c^2 + P_col * c + A_col # Args: # Perimeter_of_section: Perimeter of the column section (mm) # Area_of_section: Area of the column section (mm²) # Areq: Required area of the baseplate (mm²) # Returns: # The value of c (mm) # """ a = 4 b = Pcol c = Acol - Areq # Assuming Areq is already calculated discriminant = b ** 2 - 4 * a * c c1 = (-b + (discriminant) ** 0.5) / (2 * a) c2 = (-b - (discriminant) ** 0.5) / (2 * a) return max(c1, c2) class Parametrization(ViktorParametrization): info = Tab("Info") info.text_01 = Text( """## Welcome to baseplate design app! """ ) input = Tab("Input") input.profile_type = OptionField( "Profile type", options=["IPE", "HEA", "HEB"], default="IPE", variant="radio-inline", flex=80, ) input.nl1 = LineBreak() input.profile = AutocompleteField( "Profile", options=get_profile_types, default="IPE240", description="The source of profile properties can be found [here](https://eurocodeapplied.com/design/en1993/ipe-hea-heb-hem-design-properties)", ) # input.steel_class = OptionField( # "Steel class", options=["S235", "S275", "S355"], default="S235" # ) input.fck = NumberField('Fck', default=25, suffix="MPa") input.Design_load = NumberField('Design_load', default=1000, suffix="KN") input.acc = NumberField('Concrete coeff(acc)', default=0.85) input.yc = NumberField('Partial factor of safety for concrete', default=1.5) input.steel_class = NumberField('steel_class', default=255, suffix="MPa") class Controller(ViktorController): label = 'My Entity Type' parametrization = Parametrization @DataView("profile geometrical Properties", duration_guess=1) def display_geometrical_properties(self, params: Munch, **kwargs): """Initiates the process of rendering an image of the bending moments of the structure, as well as a view of a few key values related to the bending moments.""" # results = self.calculate_allowable_bending_moment( # params.input.profile_type, params.input.profile # ) results = self.get_geometrical_properties( params.input.profile_type, params.input.profile ) data = DataGroup( DataItem("Depth", results["Depth"], suffix="mm"), DataItem("Width", results["Width"], suffix="mm"), DataItem("Thickness_of_web", results["Thickeness_of_web"], suffix="mm"), DataItem("Thickness_of_flange", results["Thickeness_of_flange"], suffix="mm"), DataItem("Area_col", results["Area_col"], suffix="mm2"), DataItem("Perimeter_col", results["Perimeter_col"], suffix="mm"), ) return DataResult(data) def calculate_plate_geom(self, params, **kwargs): results = self.get_geometrical_properties( params.input.profile_type, params.input.profile ) # Partial factor of resistance of cross-sections whatever the class is as per EN 1993-1-1. Ym0 = 1.0 # Compute ultimate load (Ned) -> on page # Compute foundation bearing strength which is typically concrete # βj is the foundation joint material coefficient, typically taken as 0.67 as per clause 6.2.5(7) in EN 1993-1-8. beta_j = 0.67 # α is a coefficient of diffusion of the vertical load being applied to the foundation. Conservatively this can be taken as 1.5 alpha = 1.5 # αcc is the coefficient that allows for long term effects on the compressive strength of concrete vs applied actions. Taken as 0.85 in the UK National Annex -> on page # γc is the partial factor of safety of concrete. Taken as 1.5 in the UK National Annex -> on page fjd = beta_j * alpha * (params.input.acc * params.input.fck) / params.input.yc # Compute area of baseplate required Areq = (params.input.Design_load * 1000) / fjd c = calculate_c(results["Perimeter_col"], results["Area_col"], Areq) # Compute the thickness of baseplate (tp) tp = c * (3 * fjd * Ym0 / params.input.steel_class) ** 0.50 return Ym0, beta_j, alpha, fjd, Areq, c, tp @DataView("Output", duration_guess=1) def Compute_output(self, params: Munch, **kwargs): Ym0, beta_j, alpha, fjd, Areq, c, tp = self.calculate_plate_geom(params) data = DataGroup( DataItem("ultimate load ", params.input.Design_load, suffix="KN"), DataItem("beta_j", 0.67), DataItem("alpha", 1.5), DataItem("Bearing capacity of concrete support(fjd) ", round(fjd), suffix="MPa"), DataItem("Areq ", round(Areq), suffix="mm2"), DataItem(" c", round(c), suffix="mm"), DataItem("Thickness of plate", round(tp), suffix="mm"), ) return DataResult(data) @staticmethod def get_beam_profile(h, b, tw, tf, r) -> List[Point]: """Generates the points which make up the chosen profile for the column cross-section""" # Get points for top flange points = [ Point(-b / 2, (h / 2) - tf), Point(-b / 2, h / 2), Point(b / 2, h / 2), Point(b / 2, (h / 2) - tf), ] # Get curve for top right angles = np.linspace(np.pi / 2, np.pi, 10) x = r * np.cos(angles) + tw / 2 + r y = r * np.sin(angles) + h / 2 - tf - r for _x, _y in zip(x, y): points.append(Point(_x, _y)) # Get curve for bottom right angles = np.linspace(-np.pi, -np.pi / 2, 10) x = r * np.cos(angles) + tw / 2 + r y = r * np.sin(angles) - h / 2 + tf + r for _x, _y in zip(x, y): points.append(Point(_x, _y)) # Get points for bottom flange points.extend([ Point(b / 2, - (h / 2) + tf), Point(b / 2, -h / 2), Point(-b / 2, -h / 2), Point(-b / 2, -(h / 2) + tf), ]) # Get curve for bottom left angles = np.linspace(1.5 * np.pi, 2 * np.pi, 10) x = r * np.cos(angles) - tw / 2 - r y = r * np.sin(angles) - h / 2 + tf + r for _x, _y in zip(x, y): points.append(Point(_x, _y)) # Get curve for top left angles = np.linspace(0, np.pi/2, 10) x = r * np.cos(angles) - tw / 2 - r y = r * np.sin(angles) + h / 2 - tf - r for _x, _y in zip(x, y): points.append(Point(_x, _y)) # Repeat the first point to close the profile points.append(Point(-b / 2, (h / 2) - tf)) return points @GeometryView("3D baseplate View", duration_guess=1) def get_3dView(self, params: Munch, **kwargs): """Create geometry for column, base-plate and add a concrete slab underneath""" Ym0, beta_j, alpha, fjd, Areq, c, tp = self.calculate_plate_geom(params) concrete_thickness = 15 * tp steel = Material(color=Color(95, 158, 240), metalness=1) concrete = Material(metalness=0, roughness=1, opacity=0.6) h = self.get_profile_property(params.input.profile_type, params.input.profile, "Depth") b = self.get_profile_property(params.input.profile_type, params.input.profile, "Width") tw = self.get_profile_property(params.input.profile_type, params.input.profile, "Web thickness") tf = self.get_profile_property(params.input.profile_type, params.input.profile, "Flange thickness") r = self.get_profile_property(params.input.profile_type, params.input.profile, "Root radius") beam_profile = self.get_beam_profile(h, b, tw, tf, r) beam = Extrusion(beam_profile, Line(Point(0, 0, tp), Point(0, 0, 3 * h)), material=steel) base_plate = SquareBeam(sqrt(Areq), sqrt(Areq), tp, material=steel) # TODO: This area doesn't seem sufficient for large column sizes base_plate.translate((0, 0, tp / 2)) concrete_plate = SquareBeam(6 * h, 6 * h, concrete_thickness, material=concrete) concrete_plate.translate((0, 0, -concrete_thickness / 2)) return GeometryResult([beam, base_plate, concrete_plate]) @staticmethod def get_profile_property( profile_type: str, profile: str, property_name: str ) -> float: """Retrieve the profile properties based on the profile type, profile and property :param profile_type: One of the following profile types: HEA, HEB or IPE. :param profile: Profile name, eg IPE80 (IPE was given as profile_type) :param property_name: The name of the property, eg Weight """ file_path = ( Path(__file__).parent / "profiles" / f"steel-profiles-{profile_type}.csv" ) df = pd.read_csv(file_path, header=[2], skiprows=[3, 4, 5]) return df.loc[df["Profile"] == profile, property_name].item() @staticmethod def get_geometrical_properties( profile_type: str, profile: str ): """Calculates the allowable bending moment based on the given parameters. :param profile_type: One of the following profile types: HEA, HEB or IPE. :param profile: Profile name, eg IPE80 (IPE was given as profile_type) :param steel_class: The steel class, eg S235 :return: A dict with the moment of inertia, profile height, yield strength and allowable bending moment. """ file_path = ( Path(__file__).parent / "profiles" / f"steel-profiles-{profile_type}.csv" ) df = pd.read_csv(file_path, header=[2], skiprows=[3, 4, 5]) Depth = df.loc[df["Profile"] == profile, "Depth"].item() Width = df.loc[df["Profile"] == profile, "Width"].item() Thickeness_of_web = df.loc[df["Profile"] == profile, "Web thickness"].item() Thickeness_of_flange = df.loc[df["Profile"] == profile, "Flange thickness"].item() Area_col = df.loc[df["Profile"] == profile, "Area"].item() Perimeter_col = df.loc[df["Profile"] == profile, "Perimeter"].item() Perimeter_col = Perimeter_col * 1000 return { "Depth": Depth, "Width": Width, "Thickeness_of_web": Thickeness_of_web, "Thickeness_of_flange": Thickeness_of_flange, "Area_col": Area_col, "Perimeter_col": Perimeter_col }

结论

我总是遇到检查底板厚度和所需有效面积的问题，以便柱荷载能够有效地传递到地基。

利用可以帮助我进行此类检查的 Python 脚本，并使用 Viktor SDK 将脚本转换为可共享且易于访问的 Web 应用程序，这很容易，并且提高了底板设计工作流程的效率。

构建这种类型的工程应用程序可以让您仅使用手机就在施工现场充满信心，并且能够在底板等结构构件制造和放置之前检查其设计精度。