# Tag Info

Accepted

### Why are engine blocks so robust apart from containing high pressure?

If you consider only the static forces then indeed the thickness might seem over-engineered. However, engine blocks are not statically loaded. They operate in the range of a few hundred to a few ...
• 22.6k

### Why are engine blocks so robust apart from containing high pressure?

You need to consider that the complete engine block has to withstand the reciprocating forces generated by each of the pistons and con rods moving as well as the rotational forces from the rotating ...
• 13.6k
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### Is it useful to stuff my glasses with newspaper to protect them?

In itself putting paper inside a glass will make very little difference. Glass is a brittle material and tends to fail by shock and point loading. Its static tensile strength is actually pretty good. ...
• 15k

### Why are engine blocks so robust apart from containing high pressure?

The vibration, loading, and fatigue aspects have already been addressed, but a wide range of operating temperatures is another factor. A typical consumer engine can be deployed in anything from say -...
• 221
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### What is the advantage of statically indeterminate structures?

For example, take a look at the following static systems. Assume they have the same length and the same (constant) cross-section. Thus an equal allowed bending moment $M_u$. The first system is ...
• 1,146

### What is the maximum angle of a shelf angled brace?

The angle is arbitrary. One can decide which angle is more practical. However, it comes at a cost: the more the angle from the vertical the more pulling and pushing force on the anchors or escrows. ...
• 20.9k
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### Why does a continuous beam have less deflection than a pair of simply supported beams?

For a simple visual demonstration, take one of the spans in your example. If it is fully hinged, then each span can be represented as a simply-supported beam. If the beam is continuous, then each ...
• 12.7k
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As mentioned in the linked text and in @grfrazee's answer, the secret is influence lines. Or, more generically, influence surfaces. For starters, let's stick to influence lines, since they are far ...
• 12.7k
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### Do scaled models reflect strength characteristics of full size

Things scale, but not always in a nice simple way. For example consider the units of stiffness of part of the structure are $E$ (Young's Modulus) times some length, but the units of weight are $\rho$ ...
• 12.5k
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### PE exam: situations in which two question choices are close to my final answer: how to pick one?

You are worrying about the numbers and forgetting what the numbers mean. This is for the PE exam, so this is a very important topic to make clear in your mind. You solved the problem. You came up with ...
• 10.6k
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### How should one model a structural model with both line elements and area elements?

Say we have a slab supported on a beam. The centroid of the slab and the centroid of the beam are not coincident. Fortunately, in FEM software packages the geometric centroid of the element can be ...
• 2,770
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### What does it mean when actual member reaction is 100% of allowed?

This means that the member is considered to be fully loaded for a failure mode which is being analyzed by that stress calculation. Some things to (probably) keep in mind include: Some conservatism ...
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### Why the design of continuous beam is always more economical than beam with supports?

I see another answer has given input on the strength side of things, where the economics isn't as clear, so I will add that one of the crucial aspects that usually make continuous beams economical is ...
• 318

### What is the maximum angle of a shelf angled brace?

There is no maximum angle. Theoretically a shelf could be supported solely via cantilever (a support coming straight out from the wall. If the angle in use is the angle from the wall to the support, ...
• 4,408
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### Steel Roof Truss Shape Question

This looks like a Collar Beam Roof (or sometimes a Collar Tie Roof). It is often used in lightly-loaded residential construction. One popular use is to form Cathedral Ceilings. Strictly speaking this ...
• 2,631
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### Can I reduce the column moment due to beam, by setting the beam end to pin?

Yes this is correct - if you want to eliminate the moments in the columns then a pinned connection between the beam and columns will achieve this. To demonstrate this I have recreated your structure ...
• 1,217