Download
1 / 5
50 likes | 178 Views
Problem 10.103. Rod AB is attached to a block at A that can slide freely in the vertical slot shown. Neglecting the effect of friction and the weights of the rods, determine the value of q corresponding to equilibrium. 160 N. 200 mm. A. B. q. C. 800 N. 200 mm. D. 100 mm.
E N D
Problem 10.103 Rod AB is attached to a block at A that can slide freely in the vertical slot shown. Neglecting the effect of friction and the weights of the rods, determine the value of q corresponding to equilibrium. 160 N 200 mm A B q C 800 N 200 mm D 100 mm
Problem 10.103 Solving Problems on Your Own 160 N 200 mm Rod AB is attached to a block at A that can slide freely in the vertical slot shown. Neglecting the effect of friction and the weights of the rods, determine the value of q corresponding to equilibrium. A B q C 800 N 200 mm D 100 mm 1. Apply the principle of virtual work. If a system of connected rigid bodies is in equilibrium, the total virtual work of the external forces applied to the system is zero for any virtual displacement of the system. 1a. Define a virtual displacement. By using a single variable, define a virtual displacement of all the forces that do work.
Problem 10.103 Solving Problems on Your Own 160 N 200 mm Rod AB is attached to a block at A that can slide freely in the vertical slot shown. Neglecting the effect of friction and the weights of the rods, determine the value of q corresponding to equilibrium. A B q C 800 N 200 mm D 100 mm 1b. Express the total virtual work done by the forces and couples during the virtual displacement. dU = F.dr and dU = Mdq where dU is the virtual work, F is a force undergoing a virtual displacement dr, and M is a couple undergoing a virtual rotation dq. 1c. Set the virtual work to zero and solve for the variable.
Problem 10.103 Solution 160 N 200 mm A B q C 800 N 200 mm D 100 mm 160 N A 200 sin q q yA B q 200 sin q C 800 N D xD Define a virtual displacement. yA = 400 sin q dyA = 400 cos qdq xD = 100 cos q dxD = _ 100 sin qdq
160 N Problem 10.103 Solution A 200 sin q q yA B q 200 sin q C 800 N D xD sin q = 0.8 ; tan q = 0.8 q = 38.7o cos q Express the total virtual work done by the forces. Set the virtual work to zero and solve for the variable. dU = _ ( 160 N ) d yA_ ( 800 N ) dxD = 0 _ ( 160 )( 400 cos qd q ) _ (800)(_ 100 sinqdq) = 0 Virtual work:
