Wasabi
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What thickness of aluminium sheet do I need to achieve the same strength of a 1/8" steel sheet?
6 votes

Using your plate as boat hull implies a complex load profile probably involving compression, shear and bending, possibly even torsion. In such cases, it is effectively impossible to give a simple ...

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Should I model the load from a pool at the top floor of a multi-story building as live or dead?
6 votes

Given that the water level will probably remain almost entirely stable, dead loading is the way to go. In fact, the only time I imagine the water level would change is if the pool is emptied for ...

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Deflection Formula for Continous Beam
6 votes

I assume you mean a beam with three spans of equal length $L$ under the effect of a uniform distributed load, like the one displayed below. Also, I assume you're asking about the maximum displacement ...

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Maximum Shear stress in Beams
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6 votes

You've got your terms confused. The maximum shear stress at the midpoint is equal to $$\tau_{max} = 1.5\frac{V}{A} = 1.5\overline\tau$$ where $\dfrac{V}{A}=\overline\tau$, which is the average ...

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why are foundations designed at SLS
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6 votes

No. In fact, SLS frequently leads to a higher factor of safety than ULS. This is because ULS deals with whether or not the structure will collapse. It does not care whether the structure will stand ...

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How do you model a real-life truss in structural analysis software?
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6 votes

The most common way to model this structure is as follows (ignore the fact that the proportions are a bit off): So, all of the diagonals are pinned-pinned. You'll notice in the schematic, however, ...

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Does the length of a beam change upon deflection?
6 votes

Adding to @Air's answer, there's also the issue of boundary conditions. A simple span where neither support allows for axial displacements will have a slight gain in length, including along the "...

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What is the significance of hinge in the internal structure of the beam?
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5 votes

A hinge is a point where there is no restriction on rotation. For other points on a beam, the rotation to the left of a point must be equal to the rotation to the right of that same point; that is, ...

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Degrees of freedom of an internal hinge in plane beam?
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5 votes

Let's start talking not about hinges, but supports. Specifically, why do supports generate the forces (including bending moments, if applicable) they do (or don't)? Think of a simply supported beam ...

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Can I reduce the column moment due to beam, by setting the beam end to pin?
5 votes

As @pauloz1890 has already stated in his answer, if you add a hinge to a beam-column connection, you will eliminate the bending moment on your column (assuming no horizontal loads are applied). That ...

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Replacing a straight rigid link by a curved rigid link
5 votes

I understand your structure is as follows (where the circular version is just an example of a "curved" link): One thing that is clear is that this structure is isostatic, therefore the external ...

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Moments of Fixed-Fixed Beam
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5 votes

When trying to figure out whether or not a given reaction will exist at a given support, it's worth remembering what a reaction actually is. A reaction is the means by which the support resists the ...

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Are the points of inflection and contraflexure the same?
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5 votes

A point of inflection is defined as the point where a function changes from convex to concave or vice versa. For a function $f(x)$, this is frequently mathematically defined as the point where $f''(x)...

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How to draw a shear force diagram when two forces are acting at the same point
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5 votes

To answer your question, you just need to break the inclined force into its component X and Y forces: $$\begin{alignat}{4} f_x &= \dfrac{20}{\sqrt{1^2+1.5^2}}&&=11.09\text{ kN} \\ f_y &...

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How does the number of braces in a balsa wood tower affect the load capacity?
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5 votes

Elements under compression such as the vertical columns in your tower can collapse in two very different ways. The first is via simple crushing of the member. This happens when the applied load ...

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Which one is preferable? Multiple layers of reinforcements or one layer of reinforcement?
5 votes

On average, it's best to limit the number of layers of rebar. There are a few reasons for this. Firstly, the more layers you have, the more complex the construction of the beam becomes. The first ...

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Rectangular hollow section vs square hollow section
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5 votes

Obviously this depends on the relative size of the sections. Assuming that the rectangular section's smallest dimension is equal to (or greater than) the square section's side and their thicknesses ...

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How to analyze the free body diagram of a pair of scissors?
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5 votes

Your general idea is correct. Your fingers apply a force which can be translated to a moment at the rotation axis. The reaction forces applied by the object to be cut must generate an equal moment at ...

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Exactly what makes steel-concrete composite beam better than pure steel?
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4 votes

Some other answer have touched upon this, but I think it needs to be made explicit: Your mistake is in thinking that civil engineering is about making the lightest structure possible. It's not. ...

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What function does this device perform better than a flat, horizontal bench?
4 votes

You are unfortunately most likely correct, and your description even grazed right by the official terminology for such things: hostile design/architecture. As other answers have mentioned, such a ...

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can ceramic be used as a building material?
4 votes

One of the foundational principles of structural engineering is obviously safety. And one of the foundational aspects of safety is the ability to show warning signs prior to any accidents. In the case ...

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Drawing the shear and bending moment diagram of a 2D rigid frame
4 votes

This is an isostatic structure, which means it can be "trivially" solved (once one is more experienced) by hand. The first thing to do is to calculate the reactions. In this case you can see that all ...

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How to deal with a point force acting right on the hinge of a beam?
4 votes

While this beam presents five constraints ($X_A$, $Y_A$, $M_A$, $Y_F$, $Y_G$), it is in fact statically determinate. A statically indeterminate structure is one where there are more unknowns (...

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Plane Truss- Missing Member
4 votes

The first thing to note is the fact that, without some sort of bracing within BCEF, the structure is unstable. As-is, that square is completely flexible, and can flatten completely: CE can move down-...

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Beam question to find the maximum stress
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4 votes

While I agree with AndyT's philosophy of simply using the solved equations, it is important to learn the origin of these solutions, so here we go. The mistake you made was that you didn't perform the ...

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What does this equation mean?
4 votes

The $\propto$ symbol represents proportionality. So, whatever is on the left hand side is directly proportional to cross-sectional area and inversely proportional to volume. Now, as to the actual ...

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Reinforcing beam and slab with correct steel bar structure
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4 votes

Model 1 is always better, but may need some modifications Whenever you have two reinforced concrete elements, you always need to facilitate the transfer of internal stresses between them. This is ...

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Round beam deflection under its own weight
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4 votes

No, as the Wikipedia article states, a uniform load's unit is in "force per unit length" ($F/L$), which means it is a load applied along a given distance. So, if you have a 102 g beam, it weighs ...

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Does a joist have to lay "thin side" down?
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4 votes

Beams have a property we call moment of inertia ($I$) which controls how strong they are to resist bending. For rectangular beams, the equation is $$I = \frac{bh^3}{12}$$ where $b$ is the cross-...

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Building Uplift due to water pressure
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4 votes

There are a few possible solutions. You can use pile foundations, where the piles dig deep into the soil and resist the uplift. They'll work entirely in tension, instead of the usual compressive load,...

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