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14 votes

Metric bolt shear strength for a layman

For complete layman's terms, an m6 bolt can hold up an elephant. For 10 kg, the bolts won't be the weak link, it will be whatever you are bolting into. Use 3 or 4 and you will probably be fine The ...
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12 votes
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Metric bolt shear strength for a layman

For a layman, you shouldn't use bolts stressed in shear. Bolts seldom hold shear forces. Bolts are used to hold two surfaces together so that the joined components take the shear stress. It is the ...
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8 votes

Metric bolt shear strength for a layman

The first thing to know is the "grade" of the bolt is available to you. Then use the appropriate table (similar to the one below) from the standard code to determine the loading capacity of ...
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7 votes
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Deflection of a cantilever beam composed of separate (not bonded) planks

in a cantilever beam the deflection is $$\delta_{max} = \frac {PL^3}{3EI} $$ In this case assuming free sliding between the planks the load P is going to be supported equally between the 3 planks. ...
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7 votes

Why does the upper wing skin fail in buckling and lower wing skin does not?

In a wing the normal situation is that the aerodynamic force is upwards (resisting gravity). You are right that there is some shear and a fair amount of torsion, but the result is that: the top side ...
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5 votes

Why does concentrated shear force on a beam influence the whole beam?

So, we apply a point load to the end of the cantilever beam and can see that for external equilibrium, there must be shear reaction at the support. (Leaving aside for now the moment reaction that also ...
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4 votes
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What is the difference "maximum" shear stress and shear stress

The difference is in the assumptions. The first "shear stress" is simply assuming the stress is uniform over the cross section. As a result, we see a shearing force $P$ shearing a rod of uniform ...
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4 votes

Difference between shear flow and shear stress

Shear flow is a quantity which is used to conveniently solve (usually) torsional problems of thin walled beams (it has other applications also). The concept behind it is, that the stress distribution ...
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3 votes

Deflection of a cantilever beam composed of separate (not bonded) planks

Thanks to @kamran for his answer. I simulated the problem in ANSYS student v19 to verify his approach. In the pictures below, the upper beam is solid, the middle one is split into two segments and ...
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3 votes

Why does concentrated shear force on a beam influence the whole beam?

If we cut a section at any point of the beam, an equal and opposite force will be there (shear reaction) to maintain the equilibrium. So if we think it as a differential section, it will be easy to ...
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3 votes

Difference in shear stress - one bolt vs two

As others have mentioned, the load will be distributed between the bolts. How they will be distributed is more complicated, but it is usually assumed to be an equal division between the bolts (in this ...
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3 votes

Difference in shear stress - one bolt vs two

Assuming a material like cold rolled steel: The steel will yield and deform slightly at small points of very high stress , equalizing the load/stress. So the bolts will have very similar loads. This ...
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3 votes

What is the difference between tau = VQ/It and tau = V/A?

As mentioned, the formula $\tau_{avg}=\frac{V}{A}$ is called average shear stress. In some calculations it might suffice to calculate $\tau_{avg}$ for a widely used cross-section (let's say a ...
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3 votes

Metric bolt shear strength for a layman

Source, Eurocodeapplide.com Shear strength of bolts The shear resistance of the bolt per shear plane Fv,Rd is provided in EN1993-1-8 Table 3.4: Fv,Rd = αv ⋅ fub ⋅ A / γM2 where: αv is a coefficient ...
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3 votes

Metric bolt shear strength for a layman

I will start by highlighting the main points (some were also found in other answers). I will additionally provide a short calculation for the tensile strength (and shear strength) very quickly by ...
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3 votes
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Why can't I-beam resist torsion but can resist shear stress due to transverse loading?

IMHO the most important issue, is that the IPE cross-section is considered an open section with respect to torsion. This reduces the resistance to torsion significantly. Figure : Shear stress due to ...
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2 votes

Shear strength of reinforced concrete filled PVC pipe

A sketch would be helpful. But if my understanding of what you want to do is correct, you want to cover a 3 by 4 feet sump pit by light material which you could remove in case it is needed. The pvc ...
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2 votes
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Connection for beam very close to concrete wall

Full penetration weld would be ok. I am more concerned about that bolts between the beam and the concrete edge. It could be difficult to tight them and inspection would be problematic too. Also you ...
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2 votes
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Maximum shear force of metric steel bolt

The Guide to Design Criteria for Bolted and Riveted Joints 1974 by Fisher and Struik, you can use the approximation: $$S_{Ult-Shear}\sim 0.62\cdot S_{Ult}$$ and from the Distortion Energy Theory: $...
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2 votes

Maximum shear force of metric steel bolt

For metric bolts the tensile strength can be calculated from the grade of the bolt expressed as A.B (eg 8.8). The first number is the ultimate tensile stress in 100s of Mega Pascals and the number ...
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2 votes
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Determine shear flow direction in profile/beam section

Yes, shear flow in a cross sectional element will always be in the same direction as the shear force in that same cross sectional element because the shear flow is essentially the distribution of the ...
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2 votes

Deflection of a cantilever beam composed of separate (not bonded) planks

Although I agree with @kamran, I have another way of thinking about it The deflection of the structure is $$\delta=\frac{P\cdot L}{3\cdot E\cdot I}$$ The only difference in this problem between then ...
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2 votes
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Determining when bolt will bend

Assuming that nothing else will give out first, what metric would I use to estimate how much weight it can support before flexing the bolts? Is it "bending stiffness" rather than "shear strength"? ...
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2 votes

Shear force and bending moment for continuous span

You're on the right track, though there looks to be a typo in the last sentence of your question (you wrote "L1" and then typed the length for L2). In short, the "bottom" shear coefficient refers to ...
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2 votes
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Why torsional warping does not occur for shafts with circular symmetry?

Let's imagine a solid cylinder attached to a fix support at one end and free at other. We twist it at the other end by a torque. It will rotate about it's axis without warping, ( small angles ...
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2 votes

Why torsional warping does not occur for shafts with circular symmetry?

The reason is symmetry. For a circular rod under torsion, if you rotate the rod through any angle the warped shape has to look the same, because there is no "special" point around the circumference ...
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2 votes

How to calculate failure stress on a hollow pin loaded in shear

Maximum shear in a solid cylinder is $$\tau_{max}= 4/3 V_{average}$$ Maximum shear in a hollow cylinder is intuitively zero at the top and bottom of the cylinder and a maximum of 2V/A on the vertical ...
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2 votes

Why does the upper wing skin fail in buckling and lower wing skin does not?

Wings are designed as a complex structure of spars and ribs, clad with aluminum, titanium, or new composite sheathing, or in the fabric, in the early planes. The Frame has been designed to support all ...
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2 votes

Why does a beam in shear crack at 45 degrees?

In simple tension , the maximum resolved shear stress is 45 degrees to the tensile force . That is why a tensile test bar makes a "cup and cone" fracture face ; the cup edges are 45 degrees ...
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2 votes

Why does a beam in shear crack at 45 degrees?

Concrete crack is essentially caused by the diagonal tension stresses that acting normal to the crack plane. The tension stress is a maximum on a plane that is 45 degree to the analytical axes. You ...
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