有限元接触问题代码
有限元接触问题是一个广泛研究的问题,涉及到不同材料之间的接触力学分析。以下是一个简化的有限元接触问题的代码示例,以说明基本的实现思路。
假设有两个物体A和B,它们之间存在接触。首先需要进行网格划分,将物体A和物体B分别划分为有限元网格。然后,需要定义接触区域的初始条件和材料参数。
```python
import numpy as np
import matplotlib.pyplot as plt
from scipy.sparse import lil_matrix
from scipy.sparse.linalg import spsolve
# 定义网格划分函数,将物体划分为有限元网格
def generate_mesh():
    # 生成节点坐标数组
    nodes = np.array([[0, 0], [0, 1], [1, 0], [1, 1]])
    # 生成单元数组
    elements = np.array([[1, 2, 3], [2, 3, 4]])
    return nodes, elements
# 定义初始条件和材料参数
def define_parameters():
    # 定义材料参数
    young_modulus_a = 1
    young_modulus_b = 2
    poisson_ratio_a = 0.3
    poisson_ratio_b = 0.4
    # 定义接触区域初始条件
    contact_area = np.array([1, 2])
    return young_modulus_a, young_modulus_b, poisson_ratio_a, poisson_ratio_b, contact_area
# 构建刚度矩阵和力向量
def assemble_stiffness_matrix(nodes, elements, young_modulus_a, young_modulus_b, poisson_ratio_a, poisson_ratio_b):
    num_nodes = len(nodes)
    num_elements = len(elements)
    stiffness_matrix = lil_matrix((num_nodes, num_nodes))
    for i in range(num_elements):
        element = elements[i]
        node_indices = element - 1
        x_coords = nodes[node_indices, 0]
        y_coords = nodes[node_indices, 1]
        area = (x_coords[1] - x_coords[0]) * (y_coords[2] - y_coords[0])
        k = area / 2
        # 计算局部刚度矩阵
        local_stiffness_matrix_a = (young_modulus_a / (1 - poisson_ratio_a**2)) * np.array([[1, poisson_ratio_a, 0], [poisson_ratio_a, 1, 0], [0, 0, (1 - poisson_ratio_a) / 2]])
        local_stiffness_matrix_b = (young_modulus_b / (1 - poisson_ratio_b**2)) * np.array([[1, poisson_ratio_b, 0], [poisson_ratio_b, 1, 0], [0, 0, (1 - poisson_ratio_b) / 2]])
        # 计算全局刚度矩阵
        stiffness_matrix[node_indices[0], node_indices[0]] += k * local_stiffness_matrix_a[0, 0]
        stiffness_matrix[node_indices[0], node_indices[1]] += k * local_stiffness_matrix_a[0, 1]
        stiffness_matrix[node_indices[0], node_indices[2]] += k * local_stiffness_matrix_a[0, 2]
        stiffness_matrix[node_indices[1], node_indices[0]] += k * local_stiffness_matrix_a[1, 0]
        stiffness_matrix[node_indices[1], node_indices[1]] += k * local_stiffness_matrix_a[1, 1]
        stiffness_matrix[node_indices[1], node_indices[2]] += k * local_stiffness_matrix_a[1, 2]
        stiffness_matrix[node_indices[2], node_indices[0]] += k * local_stiffness_matrix_a[2, 0]
        stiffness_matrix[node_indices[2], node_indices[1]] += k * local_stiffness_matrix_a[2, 1]
        stiffness_matrix[node_indices[2], node_indices[2]] += k * local_stiffness_matrix_a[2, 2]
        stiffness_matrix[node_indices[0], node_indices[0]] += k * local_stiffness_matrix_b[0, 0]
        stiffness_matrix[node_indices[0], node_indices[1]] += k * local_stiffness_matrix_b[0, 1]
        stiffness_matrix[node_indices[0], node_indices[2]] += k * local_stiffness_matrix_b[0, 2]
        stiffness_matrix[node_indices[1], node_indices[0]] += k * local_stiffness_matrix_b[1, 0]
        stiffness_matrix[node_indices[1], node_indices[1]] += k * local_stiffness_matrix_b[1, 1]
        stiffness_matrix[node_indices[1], node_indices[2]] += k * local_stiffness_matrix_b[1, 2]
        stiffness_matrix[node_indices[2], node_indices[0]] += k * local_stiffness_matrix_b[2, 0]
python新手代码你好
        stiffness_matrix[node_indices[2], node_indices[1]] += k * local_stiffness_matrix_b[2, 1]
        stiffness_matrix[node_indices[2], node_indices[2]] += k * local_stiffness_matrix_b[2, 2]
    return stiffness_matrix
# 解决线性方程系统
def solve_linear_system(stiffness_matrix, contact_area, nodes):
    num_nodes = len(nodes)
    num_unknowns = num_nodes - len(contact_area)
    force = np.zeros(num_nodes)
    displacement = np.zeros(num_nodes)
    # 应用边界条件
    for i in range(len(contact_area)):
        node_index = contact_area[i] - 1
        force[node_index] = 1
    # 划分刚度矩阵和力向量
    stiffness_matrix_global = stiffness_matrix[0:num_unknowns, 0:num_unknowns]
    force_global = force[0:num_unknowns]
    # 解线性方程系统
    displacement_global = spsolve(stiffness_matrix_global, force_global)
    # 汇总解向量
    for i in range(num_unknowns):
        displacement[i] = displacement_global[i]
    for i in range(len(contact_area)):
        node_index = contact_area[i] - 1
        displacement[node_index] = 0
    return displacement
# 绘制位移云图
def plot_displacement(nodes, displacement):