Kinematic homework, see the attachment

homework_8.pdf

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MCE 260 Spring 2016

Homework 8, due April 4, 2015.

PRESENT CLEARLY HOW YOU DEVELOPED THE SOLUTION TO THE PROBLEMS

Each problem is worth up to 5 points. Points are given as follows:

5 points: Work was complete and presented clearly, the answer is correct

4 points: Work was complete, but not clearly presented or some errors in calculation

3 points: Some errors or omissions in methods or presentation

2 points: Major errors or omissions in methods or presentation

1 point: Problem was understood but incorrect approach was used

The fourbar linkage shown has link lengths L1=7”, L2=9”, L3=3”,

L4=8”. Link 1 is ground, and link 3 is the coupler, as usual. Link 2

pivots on the origin of the XY coordinate system. A coupler point

P is located at a distance of 9” from pivot A, at an angle of 25

from the line AB. Consider the position shown, where the angle

between links 1 and 2 is 85 degrees. Link 2 rotates at a constant

speed of 20 radians per second clockwise.

1. (5 points) Is the linkage a crank-rocker, a double rocker, a double crank, or a triple rocker?

Explain your answer.

2. (5 points) Modify the Matlab code fbpos1vec.m to determine θ3 and θ4.

3. (5 points) Differentiate the vector loop equations to get the velocity equations, and solve the

angular velocities ω3 and ω4 . Also determine the velocity of point P. Check your answer by

using LINKAGES or one of the Matlab codes from Blackboard.

4. (5 points) Differentiate the vector loop equations again to get the acceleration equations, and

solve the angular accelerations α3 and α4, Also determine the acceleration of point P. Check

your answer by using LINKAGES or one of the Matlab codes from Blackboard.

B P