Mechanism 2 – Independent Analysis

 The structure shown in Figure 3 is part of a transfer bridge used by cars to drive onto a ferry. Due to the varying tidal heights, the bridge (member AC) may be in any position from θmin = 0° to θmax = 25°. The mass of member AC, mb, is equal to the last 4 digits of your A#, in kg, and acts at the center of mass, midspan of the structure. Member BC is a hydraulic cylinder which varies in length depending on the bridge position, and may be assumed to have a negligible mass.

Analysis:

Visualize the mechanism at 𝜃𝑚𝑖𝑛 = 0°, 𝜃𝑚𝑎𝑥 = 25°, and an intermediate position θ. 2. Disassemble the mechanism and draw a free body diagram for member AC in the intermediate position. Hydraulic cylinder BC is a 2-force member. 3. Produce geometric and equilibrium relationships to relate the force in cylinder BC and the resultant pin force at A (𝑅𝐴) to the angle of the bridge, 𝜃. The analysis will be similar to that performed in the previous section of this lab. 4. Input these relationships into a spreadsheet. 5. Verify the accuracy of your spreadsheet by analysing the bridge by hand at angle 𝜃 = 15. 6. Produce a plot showing the full range of angle 𝜃 on the x-axis and cylinder force 𝐹𝐵𝐶/𝑅𝐴 on the y-axis.

Mechanism 1 – Guided Analysis

 1. FBD of mechanism in the intermediate position 

2. List of geometric and equilbrium formulas used for the analysis 

3. Screenshot of your spreadsheet 

4. Plots of a. 𝜃 vs. 𝐹𝐷𝐸 b. 𝜃 vs. 𝑅𝑜 and 𝑅𝑐  

Mechanism 2 – Independent Analysis 

1. FBD of mechanism in the intermediate position 

2. Derivation and list of the geometric and equilibrium equations used for the analysis. SHOW YOUR CALCULATIONS!! They do not have to be typed up, but they should be neat. 

3. Screenshot of your spreadsheet 

4. Hand calculation of member BC and pin forces at A for the bridge at an angle 𝜃 = 15°. 5. Plot of 𝜃 vs. 𝐹𝐵𝐶 and 𝑅𝐴 

Include a title page with the lab title, your name, A#, and the date. The report should not be formal, but it should be complete. Presentation will count for 20% of the value of this lab, so ensure your report is professional looking, neat and organized. Your digital submission must be a single PDF document. 

solution