用Fortran编悬臂梁代码

以下是用Fortran编写的悬臂梁代码：

program cantilever_beam

! This program calculates the deflection of a cantilever beam under a point load

implicit none

! Constants
real, parameter :: L = 1.0 ! Length of beam
real, parameter :: b = 0.1 ! Width of beam
real, parameter :: h = 0.2 ! Height of beam
real, parameter :: P = 1000.0 ! Point load
real, parameter :: E = 2.1E11 ! Young's modulus
real, parameter :: nu = 0.3 ! Poisson's ratio

! Variables
integer, parameter :: N = 10 ! Number of elements
real, dimension(N+1) :: x ! Node coordinates
real, dimension(N) :: L_e ! Length of each element
real, dimension(N) :: k_e ! Stiffness of each element
real, dimension(N+1) :: f ! Nodal forces
real, dimension(N+1) :: u ! Nodal displacements
real :: dx ! Element size
integer :: i ! Loop index

! Calculate nodal coordinates
dx = L / real(N)
x(1) = 0.0
do i = 2, N+1
    x(i) = x(i-1) + dx
end do

! Calculate element lengths and stiffnesses
do i = 1, N
    L_e(i) = x(i+1) - x(i)
    k_e(i) = (E * b * h / L_e(i)) * &
             (/ [1.0, -1.0; -1.0, 1.0] /) * &
             (/ 1.0, -1.0; -1.0, 1.0 /) * &
             L_e(i) / 6.0
end do

! Assemble global stiffness matrix and nodal forces
do i = 1, N
    f(i) = 0.0
    u(i) = 0.0
    u(N+1) = 0.0
    k_e(i) = k_e(i) + &
             (/ [P*L_e(i)/(6.0*E*b*h), P*L_e(i)/(12.0*E*b*h); &
                P*L_e(i)/(12.0*E*b*h), P*L_e(i)/(6.0*E*b*h)] /)
    f(i:i+1) = f(i:i+1) + (/ P/2.0, P/2.0 /)
end do

! Solve for nodal displacements
u = matmul(inv(sum(k_e)), f)

! Output nodal displacements
write(*,'(A,I2,A)') 'Nodal Displacements:'
do i = 1, N+1
    write(*,'(F10.4)') u(i)
end do

end program cantilever_beam

该代码使用有限元方法计算悬臂梁的挠度。程序首先计算节点坐标、元素长度和刚度。然后，它将节点力和点荷载组装到全局刚度矩阵中，并通过求解线性方程组来计算节点位移。最后，程序输出节点位移。