Problem 3 (60 Points) Landing gear on aircraft are typically…
Problem 3 (60 Points) Landing gear on aircraft are typically produced with lug and clevis joints to react aircraft landing as well as take-off loads. Lug-clevis joint at a location of interest on the landing gear is assembled together using a pre-loaded pin. Assume that the maximum axial tensile pre-load is 1 kips on the pin. Also, assume that the pin has a nominal outer diameter of 1.00 inch and has a solid uniform circular section. Joint dimensions, axial pin preload, applied clevis load from critical load case and corresponding details for lug-clevis joint are detailed below. Given problem shown above, provide following four part pin analysis (each part is 15 points): Part 1: Develop a free body for the pin, purple component shown above. Assume centered point loads instead of distributed loads for contact as an initial approximation. Clearly label your FBD – show all distances, values, points, units. Include pin’s axial tensile pre-load of 1 kips from assembly in your FBD. Part 2: Develop shear – moment diagram (VMT) for the pin, do not include pin pre-load. Part 3: Calculate overall max shear and max bending stresses (including pre-load effect) in the pin. State or show where max shear and max bending pin stresses occur (including pre-load effect). Part 4: Show the 2-D “plane-stress” state at the point with max bending pin stress. Sketch largest possible Mohr’s circle for point with max bending stress (including pre-load effect). Label circle radius, average stress, max shear stress, max principal and min principal stresses on Mohr’s Circle. Extra Credit (5 points each): Part 5: Calculate max shear and max/min principal stress angles for Part 4. Part 6: Sketch 2-D element for max principal and max shear stress. Show all values and angles. Part 7: Assume that given loading is a limit condition and that pin material allowables are Fsy = 19 ksi, Fsu = 22 ksi, Fty = 38 ksi, Ftu = 95 ksi. Calculate shear and bending (including pre-load effect) margins. Use a factor of safety of 1.15 and applied max principal and max shear stresses from Part 4. What is the minimum margin of safety for the point analyzed in part 4?