Presentation on theme: "ө B D 2.8 in 10 in. Problem 15.123 Collar D slides on a fixed vertical rod. Knowing that the disk has a constant angular velocity of 15 rad/s clockwise,"— Presentation transcript:
ө B D 2.8 in 10 in. Problem 15.123 Collar D slides on a fixed vertical rod. Knowing that the disk has a constant angular velocity of 15 rad/s clockwise, determine the angular acceleration of bar BD and the acceleration of collar D when… (a) = 0 (b) = 90 0 (c) = 180 0 ө ө ө Figure 1.
First, draw a circle of radius 3 in. (arbitrary length, but at least 2.8 in. long). Place a pin joint at the center of the circle, and attach a motor to the center of the circle as well. Figure 2 Next, draw a rectangle with h = 10in. and w = 0.5in. (arbitrary width). Place a point element on one side of the rectangle and a point element 2.8 in. from the center of the circle. Join the two points with the join command. Figure 3
Next, create the collar by creating a rectangle of arbitrary size. Position the collar so that its center lies 2.8 in. to the left of the center of the disk (use the boxes in the lower left hand corner of the working area to position the collar). Attach a point element to the center of the collar and a point element to the other end of the connecting rod. Join these two points with the join command. Set the motor speed to 15 rad/s clockwise. Also, use the measure pulldown to measure the acceleration of the collar and of the connecting rod. Create graphs with the measure pulldown and vectors with the define pulldown if desired. Run the simulation. Figure 4 Figure 5
Here, at = 0 0, a.α_BD= 5.58 rad/s 2 Ad = 35.882 ft/s 2 ө Figure 6
Here, at = 90 0, B. α_BD= 76.034 rad/s 2 Ad = 35.480 ft/s 2 ө Figure 7
Here, at = 180 0, c. α_BD= 5.586 rad/s 2 Ad = 69.109 ft/s 2 ө Figure 8