from sympy.physics.continuum_mechanics.cable import Cable from sympy.core.symbol import Symbol def test_cable(): c = Cable(('A', 0, 10), ('B', 10, 10)) assert c.supports == {'A': [0, 10], 'B': [10, 10]} assert c.left_support == [0, 10] assert c.right_support == [10, 10] assert c.loads == {'distributed': {}, 'point_load': {}} assert c.loads_position == {} assert c.length == 0 assert c.reaction_loads == {Symbol("R_A_x"): 0, Symbol("R_A_y"): 0, Symbol("R_B_x"): 0, Symbol("R_B_y"): 0} # tests for change_support method c.change_support('A', ('C', 12, 3)) assert c.supports == {'B': [10, 10], 'C': [12, 3]} assert c.left_support == [10, 10] assert c.right_support == [12, 3] assert c.reaction_loads == {Symbol("R_B_x"): 0, Symbol("R_B_y"): 0, Symbol("R_C_x"): 0, Symbol("R_C_y"): 0} c.change_support('C', ('A', 0, 10)) # tests for apply_load method for point loads c.apply_load(-1, ('X', 2, 5, 3, 30)) c.apply_load(-1, ('Y', 5, 8, 5, 60)) assert c.loads == {'distributed': {}, 'point_load': {'X': [3, 30], 'Y': [5, 60]}} assert c.loads_position == {'X': [2, 5], 'Y': [5, 8]} assert c.length == 0 assert c.reaction_loads == {Symbol("R_A_x"): 0, Symbol("R_A_y"): 0, Symbol("R_B_x"): 0, Symbol("R_B_y"): 0} # tests for remove_loads method c.remove_loads('X') assert c.loads == {'distributed': {}, 'point_load': {'Y': [5, 60]}} assert c.loads_position == {'Y': [5, 8]} assert c.length == 0 assert c.reaction_loads == {Symbol("R_A_x"): 0, Symbol("R_A_y"): 0, Symbol("R_B_x"): 0, Symbol("R_B_y"): 0} c.remove_loads('Y') #tests for apply_load method for distributed load c.apply_load(0, ('Z', 9)) assert c.loads == {'distributed': {'Z': 9}, 'point_load': {}} assert c.loads_position == {} assert c.length == 0 assert c.reaction_loads == {Symbol("R_A_x"): 0, Symbol("R_A_y"): 0, Symbol("R_B_x"): 0, Symbol("R_B_y"): 0} # tests for apply_length method c.apply_length(20) assert c.length == 20 del c # tests for solve method # for point loads c = Cable(("A", 0, 10), ("B", 5.5, 8)) c.apply_load(-1, ('Z', 2, 7.26, 3, 270)) c.apply_load(-1, ('X', 4, 6, 8, 270)) c.solve() #assert c.tension == {Symbol("Z_X"): 4.79150773600774, Symbol("X_B"): 6.78571428571429, Symbol("A_Z"): 6.89488895397307} assert abs(c.tension[Symbol("A_Z")] - 6.89488895397307) < 10e-12 assert abs(c.tension[Symbol("Z_X")] - 4.79150773600774) < 10e-12 assert abs(c.tension[Symbol("X_B")] - 6.78571428571429) < 10e-12 #assert c.reaction_loads == {Symbol("R_A_x"): -4.06504065040650, Symbol("R_A_y"): 5.56910569105691, Symbol("R_B_x"): 4.06504065040650, Symbol("R_B_y"): 5.43089430894309} assert abs(c.reaction_loads[Symbol("R_A_x")] + 4.06504065040650) < 10e-12 assert abs(c.reaction_loads[Symbol("R_A_y")] - 5.56910569105691) < 10e-12 assert abs(c.reaction_loads[Symbol("R_B_x")] - 4.06504065040650) < 10e-12 assert abs(c.reaction_loads[Symbol("R_B_y")] - 5.43089430894309) < 10e-12 assert abs(c.length - 8.25609584845190) < 10e-12 del c # tests for solve method # for distributed loads c=Cable(("A", 0, 40),("B", 100, 20)) c.apply_load(0, ("X", 850)) c.solve(58.58, 0) # assert c.tension['distributed'] == 36456.8485*sqrt(0.000543529004799705*(X + 0.00135624381275735)**2 + 1) assert abs(c.tension_at(0) - 61717.4130533677) < 10e-11 assert abs(c.tension_at(40) - 39738.0809048449) < 10e-11 assert abs(c.reaction_loads[Symbol("R_A_x")] - 36465.0000000000) < 10e-11 assert abs(c.reaction_loads[Symbol("R_A_y")] + 49793.0000000000) < 10e-11 assert abs(c.reaction_loads[Symbol("R_B_x")] - 44399.9537590861) < 10e-11 assert abs(c.reaction_loads[Symbol("R_B_y")] - 42868.2071025955 ) < 10e-11