# Homework Help: Shear flow in built of beam

1. Aug 8, 2013

### aahas3

Im having difficulty figuring this question as their are not enough notes or guides on longitudinal shear on bolts.

Shear flow(q/s) = VQ/I
Yc = 100

I = 3.65 X 10^8 MM^4
Q = Ax Y'
Q = 150 X 25 X 87.5 = 3281250 As analysing shear in the longitudinal which means taken consideration of either top or bottom. However, if not symmetrical would i have to consider both to and bottom in the equation for the maximum shear of the bolt or choose and side as a control and then compare.

Based on these results and knowing spacing is s =90 mm and that 2 bolts should be considered, not sure about this bit of it as it occurs longitudinal do i take it being 3 bolts that go parallel to the box or the bolts perpendicular to the face ie 2 bolts ?.

250 shear per bolt so q = 500

500 / 90 = V* 3281250/ I
V = 617.91 however the answer in the book (refer to bottom of the question sheet) with no real guide of solution.

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2. Aug 10, 2013

### pongo38

Consider top. VQ/I gives you the shear force per unit length of beam. If s is the spacing of bolts, then VQs/I gives the shear force per bolt (group). In this case there are two bolts per group because, when you calculate Q, it refers to an area above the neutral axis, encompassing two bolts (per 50 mm) at the same level.

3. Aug 13, 2013

### pongo38

Sorry. I made a mistake in #2. VQb/I gives you the shear force per unit length of beam, as you could well verify from the units. Then VQbs/I gives the shear force per bolt (group)