Questions tagged [structural-engineering]
Questions related to the integrity, design requirements, or analysis of structures.
1,081
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Why not use sodium hydroxide to reduce carbon dioxide emissions?
The products of the reaction are useful. Renewables like solar power can be used for the electrolysis of brine.
I don't understand why petrochemical companies are not using it as a scrubber?
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39 views
I need to know this about fire sprinklers for my fire year project
do structural engineers consider the dead load of the pipe and the water inside the pile when design buildings? how is it done
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83 views
A problem on beams
Problem -
I have interpreted "by hinging them together at B" as following -
Now if this is the case, then applying a load on the right beam will have no effect, in my understanding, on ...
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1answer
32 views
derive functions for generating projections for the interpenetration of two cylinders for making fittings
I want to make custom fittings for constructing large molecular models using copper tubing.
I will need to cut a hole in one piece of tubing that will closely fit around another inserted piece. I ...
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1answer
62 views
Slope of the Bending moment diagram where a point force acts
Consider a beam that is arbitrarily loaded and at any distance x, we take an element in the beam between two sections, where a point force acts as shown.
Let us assume the directions of shear force ...
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2answers
43 views
Relationship between shear force and load intensity
The book I'm referring to for studying beams, said that its quite cumbersome to construct shear force and bending moment diagrams, by writing the SF and BM equations for each segment of the beam and ...
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1answer
29 views
How much load could the ceiling hold
I am replacing the ceiling in my flat with some soundproofing materials and since these are heavier than usual materials used I want to check if the new materials would pose a problem.
The room I want ...
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3answers
37 views
Concentrated and Distributed loads in regards to moments
A load is any externally applied force or moment.
A load which is spread over a very small area of the beam is called a concentrated load.
A load which is spread over a significant area of the beam ...
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1answer
36 views
Concerned about snow and dirt getting into the drive chain based on my design
I am working on building an autonomous snow thrower similar to the one in this video.
I tore an old RX73 tractor down to just the chassis, by removing the engine, transmission, mower deck, brakes ... ...
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Are there any instances on Earth where it must be necessary to distinguish between center of mass and center of gravity?
Distinguishing between center-of-mass as the geometric centroid pondered by mass (the average point of the object(s) using mass as the weight of the sum) and the center-of-gravity as the centroid ...
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79 views
How many more degrees of tilt can the Millennium Tower in San Francisco withstand before it becomes structurally unsound? [closed]
How many more degrees of tilt can the Millennium Tower in San Francisco withstand before it becomes structurally compromised/unsound?
"...An examination in 2016 showed the building had sunk 16 ...
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80 views
Difference between Stiffness (K) and Modulus of Elasticity (E)?
Stiffness (F=Kx) is the extent to which an object resists deformation in response to an applied force. Elastic Modulus (E=Stress/Strain) is a quantity that measures an object or substance's resistance ...
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2answers
30 views
Shear force in a beam at ends
Consider a cantilever beam acted upon by a point load at its free end. The shear force diagram is shown.
I have a little doubt,is the shear force at x= 0 ,both 0 and $-W$ or just $-W$? Similarly at ...
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2answers
48 views
How can I find the right resonant frequency of a chassis?
Structures have infinite DOFs, so it possess infinite mode shapes. How can we find the right resonant frequency out of the infinite resonant frequencies so that we can save our structure?
For example, ...
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3answers
49 views
Castigliano's theorem for deflection
Consider a prismatic bar fixed at one end and acted upon by a force P at the other. According to Castigliano's theorem we can determine the deflection of point A by partially differentiating the total ...
2
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1answer
38 views
A close coiled helical spring with torque acting about longitudinal axis
Consider a close coiled helical spring which is acted upon by a torque about its longitudinal axis as shown. I'm interested in knowing the effect of this torque on the spring wire.
Here's my take: I ...
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1answer
67 views
Bolted connection moment resistance
I'm reading the Steel Construction Institute book Moment-resisting joints to Eurocode 3.
In chapter 2, bolted beam to column connections using end plates are covered. For a connection with multiple ...
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2answers
44 views
Deformation of a plane in Torsion of a Circular Shaft
Consider a shaft which is fixed at one of the ends and is acted upon by a torque at the free end as shown.
We take a plane inside the shaft as shown in the figure before the torque is applied. I'm ...
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0answers
34 views
Electric heating element inside refractory concrete
I'm thinking of making an electric pizza oven in my free time. My thinking at the moment is to have one kilowatt electric heating elements in the bottom as well as the top of pizza oven. I would like ...
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1answer
26 views
Why is the unit load facing upwards? Flexibility/Force Method
I used the flexibility method to solve questions like this, so I know you have to have a primary and secondary structure. My primary structure looks like this:
So if I apply my virtual load, I got ...
4
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1answer
92 views
What is this strange "French balcony" on a newly built house in California, USA?
While randomly browsing around in Google Street View, amazed by how surprisingly cozy they managed to make this neighborhood, I found something very strange. What looks almost like a "French ...
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3answers
273 views
Torsion - Circular vs Non-circular shafts
The book I'm referring to says that a shaft with a circular cross section in pure torsion will have it's cross sections remain flat during the loading. That is, the cross sections won't deform, they ...
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2answers
106 views
Solutions for a slanted roof
I'm using I-Joists to span this 27' vaulted living room and create a shed style roof. I've got two problems. Because of the angle, the joist won't make full contact with the walls (short of 20 years ...
2
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2answers
70 views
How to estimate the number of elevators required in a building?
I've been asked to estimate the number of elevators in a mixed use building with 37 floors (4 basement-parking floors), & design their operation.
Are their any specifications/guides/manuals that ...
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2answers
36 views
Who takes care of structural health monitoring of civil structures?
There are numerous studies about the possibility of structural health monitoring (SHM) of tall structures, like bridges, skyscrapers, water towers, wind turbines, where, for example, inclination or ...
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2answers
48 views
Water flow near dam geomechanics
I have basic Geomechanics question , one of the drawing is true and the others are wrong , which one ? , explain why the others are wrong .
First one wrong because the number of squares are not equal
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2answers
102 views
Do yielded columns buckle?
A sufficiently slender column will fail under compression below yield stress by bowing, releasing it's axial elastic strain. This is called buckling. Depending on the slenderness of the column, the ...
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2answers
53 views
A question on thermal stresses
I'm studying strength of materials at undergrad level and was taking a test in the same. One of the questions from the test goes like this
In my understanding since the coefficient of thermal ...
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3answers
57 views
Question about how to study for engineering university exams [closed]
What are some of the ways to predict exam questions from class lectures in university final exams? How should one understand the mindset of the professor & find out important maths/questions he ...
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2answers
59 views
How to calculate the deflection displacement of a circular looped, closed bending beam?
There is a given ring A, with a given cross section B. Ring A is placed on Columns C. The number of the columns is a variable, but minimum three.
The linear distance X between two columns can be ...
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1answer
64 views
What were these two objects from the top of a tall building in the 1920s used for?
I saw this in a movie from the 1920s, set in the USA. ("Safety Last".)
At the top of a tall building, there are two strange objects which I believe I've seen before but never could figure ...
2
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1answer
31 views
How to model compressive loads and stability of hexagonal brick in vertical orientation
Imagine a honeycomb-like structure of hexagons, then turn it on its side. Now suppose instead of open cells, assume each cell is a solid masonry casting (a brick). While the structural properties and ...
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2answers
31 views
Sheathing carrying vertical load more than studs
When wooden walls are created and sheathed in place before erecting (sheathing does go all the way to sill and top plates) some studs don’t have a great connection to top or sill plates because of ...
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2answers
52 views
Transfer of Moments down a Column
I'm designing a column for a multi-storey structure. On each level of the structure, moments are transferred to it from beams which are fully fixed to the column. At the first floor (i.e. one level up ...
2
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1answer
70 views
Why does the IRC think ceiling joists are weaker than floor joists?
According to the IRC, a 1200S162-68 cold-formed steel C-section can hold 40psf total load at an almost 22' span when used as a floor joist, but can only hold 25psf total load at a 21' span when used ...
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1answer
33 views
Shear capacity according to eurocode , when to use which equation
I am looking at eurocode to calculate shear capacity, and under section "6.2.6 Shear", there are two different shear checks:
Eq 6.18
Eq 6.19
When there is no torsion we can use equation 6....
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3answers
98 views
Design procedure used in beam design
In the design of beams, the principal stresses and absolute maximum shear stresses are not calculated. Instead, we calculate maximum bending stress using flexure formula and equate it to allowable ...
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2answers
58 views
Very confused as how to calculate the degree of static indeterminacy of trussed beam
I was working earlier on an example problem of a trussed beam. Above you can see a picture illustrating the situation. On top there is a simply supported beam, with a stiffening truss below. The truss ...
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2answers
49 views
Waterlogged multistorey apartment
I fraction invested in a real estate project several years back. Mid way through the construction, after about 12 floors, the building contractor filed for bankruptcy. An asset reconstruction company ...
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3answers
76 views
Beam with width tending to zero
Suppose a cantilever beam (of rectangular cross-section) subjected to vertical transverse shear load at free end. If I consider any arbitrary cross-section then both bending and shear stress will be ...
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3answers
154 views
Interpretation of dimensionless numbers as ratios of forces
How can the dimensionless numbers like reynolds number etc be interpreted as ratio of the various forces? The explanation given by most sources in this regard seems quite unsatisfactory and not much ...
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3answers
121 views
Tension cable underneath rafter tie?
I just bought a new property with a large garage and I'm curious about the roof structure. The roof structure is supported entirely on the front/rear walls using rafter and collar ties. The rear wall ...
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4answers
44 views
Will A Material Plastically Deform If you Slowly Apply a Strain That Would Normally Exceed Its Ultimate Tensile Strength
Lets I have a material with ultimate tensile strength $S_{UTS}$.
Lets say $S_{UTS}$ is produced by strain $\epsilon_{UTS}$
My question is, if the material is strained such that it achieves $\epsilon_{...
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2answers
61 views
Do we have infinite number of stresses at a point in a prismatic bar loaded in tenison?
Consider a prismatic bar loaded in tension as shown. I consider a point Q in the bar away from the ends. This point Q can be considered as an infinitesimally small element taken within the body.
We ...
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1answer
62 views
How to find clamping force from bolt preload?
If I have a piece of rubber between two steel plates, and four bolts (at equal preload) compressing the plates, will the total compressive force on the rubber be Preload x 4?
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1answer
27 views
How to apply restraints on member which is on grade (continuous support)?
ETABS has option for providing restraints on joints, but how does one provide restraint to an entire member which is supported by ground ?
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1answer
23 views
How to hang weight from beam
I have a 4"x10" wood beam that I want to hang a swing from, but the top of it is not accessible (the roof is above).
Would it be more stable/load bearing to do a shoulder eye bolt with a nut ...
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3answers
61 views
How does one conclude that the beams in this problem will be inclined?
I was practicing some problems of axially loaded members in Strength of Materials, when I stumbled upon this one:
Two initially horizontal beams connected by aluminum and copper wires. Both the wires ...
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1answer
30 views
Calculating member stress in a truss
I have the following question:
Here is my attempt:
Is this correct ?
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2answers
42 views
Sheet Metal Panel Install on Roof
I work as a Design Engineer for an industrial ventilation company. In order to complete our outlet for our ventilaion system, we need to install a 54" by 40" steel panel (16 gauge mild steel)...
