import sectionproperties.pre.sections as sections
from sectionproperties.analysis.cross_section import CrossSection
# create a 50 diameter circle discretised by 64 points
geometry = sections.CircularSection(d=50, n=64)
geometry.plot_geometry() # plot the geometry
# create a mesh with a mesh size of 2.5
mesh = geometry.create_mesh(mesh_sizes=[2.5])
section = CrossSection(geometry, mesh) # create a CrossSection object
section.display_mesh_info() # display the mesh information
section.plot_mesh() # plot the generated mesh
# perform a geometric, warping and plastic anaylsis, displaying the time info
section.calculate_geometric_properties(time_info=True)
section.calculate_warping_properties(time_info=True)
section.calculate_plastic_properties(time_info=True)
# print the results to the terminal
section.display_results()
# get the second moments of area and the torsion constant
(ixx_c, iyy_c, ixy_c) = section.get_ic()
j = section.get_j()
# print the sum of the second moments of area and the torsion constant
print("Ixx + Iyy = {0:.3f}".format(ixx_c + iyy_c))
print("J = {0:.3f}".format(j))
# merge the two sections into one geometry object
geometry = sections.MergedSection([ub, panel])
geometry.clean_geometry() # clean the geometry
geometry.plot_geometry() # plot the geometry
# create a mesh - use a mesh size of 5 for the UB, 20 for the panel
mesh = geometry.create_mesh(mesh_sizes=[5, 20])
# create a CrossSection object - take care to list the materials in the same order as entered into
# the MergedSection
section = CrossSection(geometry, mesh, materials=[steel, timber])
section.display_mesh_info() # display the mesh information
# plot the mesh with coloured materials and a line transparency of 0.5
section.plot_mesh(materials=True, alpha=0.5)
# perform a geometric, warping and plastic analysis
section.calculate_geometric_properties(time_info=True)
section.calculate_warping_properties(time_info=True)
section.calculate_plastic_properties(time_info=True, verbose=True)
# perform a stress analysis with N = 100 kN, Mxx = 120 kN.m and Vy = 75 kN
stress_post = section.calculate_stress(N=-100e3,
Mxx=-120e6,
Vy=-75e3,
time_info=True)
# print the results to the terminal
section.display_results()
class OneSec:
"""表示一个截面"""
def __init__(self, pls):
"""
单独截面
:param pls: 多条 cad 多段线对象组成的列表，其中应有一根指示控制点的线
"""
# 原始线和控制点
self.pls_origin = []
self.points = []
for i in pls:
if i.area == 0:
self.points = i.id
else:
self.pls_origin.append(i)
# 对线段进行排序，得到分离节点和完整节点
self.areas = np.array([i.area for i in self.pls_origin])
self.pls = np.array(self.pls_origin)[np.argsort(self.areas)][::-1]
self.ids_sep = [i.id for i in self.pls]
self.ids = [j.tolist() for i in self.ids_sep for j in i]
# 获取节点连接方式
self.faces = []
id_num = 0
for i in self.ids_sep:
id_num_0 = id_num
for j in i:
connect = [
id_num, id_num_0
] if id_num + 1 == id_num_0 + len(i) else [id_num, id_num + 1]
self.faces.append(connect)
id_num += 1
# 定义其他所需值
self.geo = 0
self.mesh = 0
self.sec = 0
self.prop = {}
self.stress = 0
self.corner = []
self.ids_to_c = []
def sec_cal(self, mesh=0.01, d=0.03):
"""
对单个截面进行属性计算
:param mesh: 截面划分单元尺寸
:param d: 截取形心附近应力范围
:return: 无
"""
self.geo = sections.CustomSection(self.ids, self.faces,
self.points[1:], [self.points[0]])
self.mesh = self.geo.create_mesh(mesh_sizes=[mesh])
self.sec = CrossSection(self.geo, self.mesh)
self.sec.plot_mesh()
self.sec.calculate_geometric_properties()
self.sec.calculate_warping_properties()
# 获取截面属性
prop = self.sec.section_props
self.prop['center'] = self.sec.get_c()
self.ids_to_c = [i - self.prop['center'] for i in self.ids_sep]
self.prop['area'] = prop.area
self.prop['as'] = [prop.A_s22, prop.A_s11]
self.prop['i'] = [prop.j, prop.ixx_c, prop.iyy_c]
pts = np.array(self.ids)
left = prop.cx - pts[:, 0].min()
right = pts[:, 0].max() - prop.cx
top = pts[:, 1].max() - prop.cy
bot = prop.cy - pts[:, 1].min()
self.prop['c'] = [right, left, top, bot]
self.stress = self.sec.calculate_stress(Vx=1, Vy=1)
stresses = self.stress.get_stress()
dy = self.sec.get_c()[1] - self.sec.mesh_nodes[:, 1]
dx = self.sec.get_c()[0] - self.sec.mesh_nodes[:, 0]
qyb = stresses[0]['sig_zy_vy'][dx < d].max() * prop.ixx_c
qzb = stresses[0]['sig_zx_vx'][dy < d].max() * prop.iyy_c
self.prop['q'] = [qyb, qzb]
self.prop['p'] = [
self.pls[0].length,
sum([i.length for i in self.pls[1:]])
]
# 获取角点
pt_all = self.ids_to_c[0]
pt_1 = pt_all[(pt_all[:, 0] < 0) & (pt_all[:, 1] > 0)]
pt_2 = pt_all[(pt_all[:, 0] > 0) & (pt_all[:, 1] > 0)]
pt_3 = pt_all[(pt_all[:, 0] < 0) & (pt_all[:, 1] < 0)]
pt_4 = pt_all[(pt_all[:, 0] > 0) & (pt_all[:, 1] < 0)]
pt_1 = find_pt(pt_1, relation='max')
pt_2 = find_pt(pt_2, relation='max')
pt_3 = find_pt(pt_3, relation='max')
pt_4 = find_pt(pt_4, relation='max')
self.corner = [pt_1, pt_2, pt_4, pt_3]
