- #1

MrJoseBravo

- 10

- 0

## Homework Statement

http://prntscr.com/7rtrep

http://prntscr.com/7rts95

## Homework Equations

theta = TL/GJ

t(max)= Tc/J

## The Attempt at a Solution

The two questions i have are rather similar so i put them up at the same time, i hope that's okay.

For the first one ( the first link) i started by

angle of twist = 0 , thus TbcLbc + TcdLcd + TdaLda = 0 (1)

so then i have to find some way to relate those torques to the reactions at ends A and B. I assumed Tb to be positive (in tension) and worked my way up the shaft drawing free body diagrams.

my results : (2)

Tb = -Tbc

Tcd = -Tb + 800

Tad = -Tb+300

then i plugged equations 2 into 1 and solved for Tb.

my result was 645N-m which doesn't make sense to me since the net torque experienced by the member should be 300N-m.

I may have some conceptual information messed up in my head, any insight would be wonderful!

for the second link, id only like to know if I am thinking about it correctly.

I can find the reactions at the fixed supports, and create equations that relate them to the torques along different segments of the bar. Would i then do this

tmax=Tac(c)/J

?

thank you in advance for any insight!