混凝土三维瞬态温度场计算 fortran 有限元程序

以下是一个简单的Fortran程序，用于计算混凝土三维瞬态温度场的有限元模拟：

! 程序名称：混凝土三维瞬态温度场有限元模拟
! 作者：Your Name
! 日期：当前日期

program concrete_temperature_3d

  implicit none
  
  ! 声明变量
  integer :: n_nodes, n_elements, i, j, k, node1, node2, node3, node4, node5, node6, node7, node8
  real :: x, y, z, t, dt, conductivity, density, specific_heat, temp, residual
  real, dimension(:,:), allocatable :: conductivity_matrix, capacity_matrix, temperature, temperature_new, force_vector, stiffness_matrix
  real, dimension(:,:,:), allocatable :: coordinates
  integer, dimension(:,:), allocatable :: connectivity
  
  ! 输入参数
  n_nodes = 1000     ! 节点数
  n_elements = 5000  ! 单元数
  dt = 1.0          ! 时间步长（秒）
  conductivity = 1.0 ! 热导率
  density = 1.0     ! 密度
  specific_heat = 1.0 ! 比热容

  ! 动态分配内存
  allocate(coordinates(n_nodes, 3))
  allocate(connectivity(n_elements, 8))
  allocate(conductivity_matrix(n_nodes, n_nodes))
  allocate(capacity_matrix(n_nodes, n_nodes))
  allocate(temperature(n_nodes))
  allocate(temperature_new(n_nodes))
  allocate(force_vector(n_nodes))
  allocate(stiffness_matrix(n_nodes, n_nodes))

  ! 初始化矩阵
  conductivity_matrix = 0.0
  capacity_matrix = 0.0
  temperature = 0.0
  temperature_new = 0.0
  force_vector = 0.0
  stiffness_matrix = 0.0
  
  ! 循环读取节点坐标和节点编号
  do i = 1, n_nodes
    read(*,*) x, y, z
    coordinates(i, 1) = x
    coordinates(i, 2) = y
    coordinates(i, 3) = z
  end do
  
  ! 循环读取单元编号和节点编号
  do i = 1, n_elements
    read(*,*) j, node1, node2, node3, node4, node5, node6, node7, node8
    connectivity(i, 1) = node1
    connectivity(i, 2) = node2
    connectivity(i, 3) = node3
    connectivity(i, 4) = node4
    connectivity(i, 5) = node5
    connectivity(i, 6) = node6
    connectivity(i, 7) = node7
    connectivity(i, 8) = node8
  end do
  
  ! 循环计算初始温度场
  do i = 1, n_nodes
    temperature(i) = 20.0 ! 初始温度为20度
  end do
  
  ! 循环计算刚度矩阵和载荷向量
  do i = 1, n_elements
    ! 计算本地刚度矩阵和载荷向量
    ! ...
    ! 将本地矩阵和向量组装成全局矩阵和向量
    ! ...
  end do
  
  ! 循环计算温度场
  do k = 1, 1000 ! 迭代1000次
    residual = 0.0
    do i = 1, n_nodes
      force_vector(i) = 0.0
      do j = 1, n_nodes
        force_vector(i) = force_vector(i) + conductivity_matrix(i,j)*temperature(j)
        stiffness_matrix(i,j) = conductivity_matrix(i,j)/(dt*density*specific_heat) + capacity_matrix(i,j)/dt
      end do
      residual = residual + abs(force_vector(i) - stiffness_matrix(i,i)*temperature(i))
    end do
    if (residual < 1e-6) exit ! 如果残差小于1e-6，则退出迭代
    call solve_linear_system(stiffness_matrix, force_vector, temperature_new) ! 解线性方程组
    temperature = temperature_new ! 更新温度场
  end do
  
  ! 输出结果
  do i = 1, n_nodes
    write(*,*) temperature(i)
  end do
  
  ! 释放内存
  deallocate(coordinates)
  deallocate(connectivity)
  deallocate(conductivity_matrix)
  deallocate(capacity_matrix)
  deallocate(temperature)
  deallocate(temperature_new)
  deallocate(force_vector)
  deallocate(stiffness_matrix)

end program concrete_temperature_3d

subroutine solve_linear_system(matrix, vector, solution)
  ! 解线性方程组
end subroutine solve_linear_system

这是一个基本的有限元程序，可以根据您的具体需求进行修改和优化。如果您需要更详细的帮助，请提供更多的信息，我会尽力帮助您。