The diagram in Figure 1 shows a 4bar linkage system The angu
The diagram in Figure 1 shows a 4-bar linkage system. The angular velocity of bar 1 (link AB) is a constant ?(dot)=10 rad/s.
a. Determine the velocity and acceleration of points A, B, C, and D when ?1= 90?.
B L20.2m -0 2 L3=0.2m A 0.1m D//0; 0.2m Figure 1: Diagram of four-bar linkageSolution
solution:
1) here above problem is solved by vector algebra method,where loop closure equation is given by
ad\'=ab\'+bc\'+cd\'
in vector form as
R1\'=R2\'+R3+R4\'
z2=90
wher R1=.2236 m and and angle z1=153.43 degree
2) here by chace solution we get
R1\'-R2\'=R3\'+R4\'
so we get
R3\'-R4\'=R\'=-.1788i-.01054j
where its unit vector is given by
R^=-.9983i-.05884j
3) here by chace solution we get
x2+y2=R3\'^2
x2+(R-y)2=R4^2
here value of x,y as pint of intersection as
y=R^2+R3^2-R4^2/2*R=.08955 m
on putting value we get
x=.1788 m
here R3 and R4 is given as
R3\'=x(R^*K^)+yR^
R3\'=-.2677i+.01578j
from this we get angle z3=-3.373
R4\'=R\'-R3\'=.0889i-.0263j
angle z4=-16.49 degree
5)here by by differenting this equation we get
R1\'=R2\'+R3\'+R4\'
on differenting removing zero term we get
R2w2(R2^*k^)+R3w3(R3^*k^)+R4w4(R4^*k^)=0
on solving for i and j part we get
.1996w2+.1917w3=0
-.0117w2-.0567w3+1=0
on solving we get
w2=20.81 rad/s
w3=-21.67ad r/s
6) on again differntiating we get accelartion equation as follows
R2a2(R2^*k^)-R2w2^2(R2^)+R3a3(R3^*k^)-R3w3^2(R3^)+R4a4(R4^*k^)-R4w4^2(R4^)=0
on equating we get finall answer as follows
.2cos3.373*a3+.2cos16.49*a4-176.51=0
-.2sin3.373*a3-.2*sin16.49*a4+21.754=0
on solving we get
a3=544.28 rad/s2
a4=249.65 rad/s2
8) in the same way quaestion b can be solved for angle 30 degree

