Question

strengths

Answer 1

@mathmate

Answer 2

@mathmate

Answer 3

where is z measured from?

Answer 4

Z is like yb, the neutral distance, measured from the bottom.
Your calculations of yb measure from the bottom of the section, which is perfectly normal.

Answer 5

so is it from the right edge to the centroid along the z axis?

Answer 6

both y and z are measured from the "back" of the angle for purposes of calculation of centroidal axes. After that, the reference is usually made with respect to the centroidal axes.
I have to review a little on asymmetrical section, because there is a torsion involved.
But do continue.

Answer 7

let me calculate this.

Answer 8

I have basically the same yb and zb as you.

Answer 9

okay cool. Hold on give me a sec.

Answer 10

I got -14.7 ksi

Answer 11

You're faster than me. I have to check on a few things first.

Answer 12

but keep going.

Answer 13

it's wrong. I just checked.

Answer 14

I know what I did wrong.

Answer 15

with my change I got -12.05

Answer 16

wait wait...

Answer 17

yeah I got it right. -17.4 ksi

Answer 18

Can you tell me what you did to get that?

Answer 19

give me a sec.

Answer 20

I am doing the next part.

Answer 21

Wow, that's great! Keep going, I think you're on a roll.
I am behind with this sort of problems, so can only try to help if you get stuck!

Answer 22

Yep, that looks like equation 132, and it works!

Answer 23

okay I am stuck. So I am using the same equation. I am looking for stress at point K.

for y = -0.900

for z = 1.9606

Answer 24

I got it.

Answer 25

My z was wrong. It suppose to be z = 2.3106

Answer 26

I have the equationn to solve this. I am plugging numbers in.

Answer 27

hmmm do you want to see what equation I am using?

Answer 28

yeah, please post.

Answer 29

Nice, was the beta accepted?

Answer 30

no. I got -61.6*

Answer 31

Since you only have Mz, so that reduces to tan(beta)=Iyz/Iy, right?

Answer 32

hold on here. I think I found a mistake.

Answer 33

yep, it was a mistake.

Answer 34

it was suppose to be -38.7*

Answer 35

These are my last two problems.

Answer 36

okay so stress T max I am not getting correct, however I got stress C max correct which is -17.4 ksi.

Answer 37

Is Cmax at H?

Answer 38

yes

Answer 39

and for Tmax, where is it located?

Answer 40

Is it at the bottom of K?

Answer 41

yes

Answer 42

At point K.

Answer 43

The max T should be the bending stress at K found previously.

Answer 44

I expect max. bending to be at the outermost of a section, like below K, or at the outer corner of the two legs.

Answer 45

okay let me think about this a bit more. I think I know what you are talking about. Hold on.

Answer 46

I am using the same equation that I used to solve for stress at k and h. So in this case my y and z would be?

Answer 47

With reference to centroid?

Answer 48

wait I think I got it.

Answer 49

y = 1.25 but still not correct.