示例#1
0
def test_variable_moment():
    E = Symbol('E')
    I = Symbol('I')

    b = Beam(4, E, 2*(4 - x))
    b.apply_load(20, 4, -1)
    R, M = symbols('R, M')
    b.apply_load(R, 0, -1)
    b.apply_load(M, 0, -2)
    b.bc_deflection = [(0, 0)]
    b.bc_slope = [(0, 0)]
    b.solve_for_reaction_loads(R, M)
    assert b.slope().expand() == ((10*x*SingularityFunction(x, 0, 0)
        - 10*(x - 4)*SingularityFunction(x, 4, 0))/E).expand()
    assert b.deflection().expand() == ((5*x**2*SingularityFunction(x, 0, 0)
        - 10*Piecewise((0, Abs(x)/4 < 1), (16*meijerg(((3, 1), ()), ((), (2, 0)), x/4), True))
        + 40*SingularityFunction(x, 4, 1))/E).expand()

    b = Beam(4, E - x, I)
    b.apply_load(20, 4, -1)
    R, M = symbols('R, M')
    b.apply_load(R, 0, -1)
    b.apply_load(M, 0, -2)
    b.bc_deflection = [(0, 0)]
    b.bc_slope = [(0, 0)]
    b.solve_for_reaction_loads(R, M)
    assert b.slope().expand() == ((-80*(-log(-E) + log(-E + x))*SingularityFunction(x, 0, 0)
        + 80*(-log(-E + 4) + log(-E + x))*SingularityFunction(x, 4, 0) + 20*(-E*log(-E)
        + E*log(-E + x) + x)*SingularityFunction(x, 0, 0) - 20*(-E*log(-E + 4) + E*log(-E + x)
        + x - 4)*SingularityFunction(x, 4, 0))/I).expand()
示例#2
0
文件: test_beam.py 项目: cklb/sympy
def test_variable_moment():
    E = Symbol('E')
    I = Symbol('I')

    b = Beam(4, E, 2*(4 - x))
    b.apply_load(20, 4, -1)
    R, M = symbols('R, M')
    b.apply_load(R, 0, -1)
    b.apply_load(M, 0, -2)
    b.bc_deflection = [(0, 0)]
    b.bc_slope = [(0, 0)]
    b.solve_for_reaction_loads(R, M)
    assert b.slope().expand() == ((10*x*SingularityFunction(x, 0, 0)
        - 10*(x - 4)*SingularityFunction(x, 4, 0))/E).expand()
    assert b.deflection().expand() == ((5*x**2*SingularityFunction(x, 0, 0)
        - 10*Piecewise((0, Abs(x)/4 < 1), (16*meijerg(((3, 1), ()), ((), (2, 0)), x/4), True))
        + 40*SingularityFunction(x, 4, 1))/E).expand()

    b = Beam(4, E - x, I)
    b.apply_load(20, 4, -1)
    R, M = symbols('R, M')
    b.apply_load(R, 0, -1)
    b.apply_load(M, 0, -2)
    b.bc_deflection = [(0, 0)]
    b.bc_slope = [(0, 0)]
    b.solve_for_reaction_loads(R, M)
    assert b.slope().expand() == ((-80*(-log(-E) + log(-E + x))*SingularityFunction(x, 0, 0)
        + 80*(-log(-E + 4) + log(-E + x))*SingularityFunction(x, 4, 0) + 20*(-E*log(-E)
        + E*log(-E + x) + x)*SingularityFunction(x, 0, 0) - 20*(-E*log(-E + 4) + E*log(-E + x)
        + x - 4)*SingularityFunction(x, 4, 0))/I).expand()