Questions tagged [structural-engineering]
Questions related to the integrity, design requirements, or analysis of structures.
1,003
questions
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2answers
42 views
Calculating break point (bend) of a material
I'm trying to compare a really tough polyurethane to baltic birch plywood to see if I can use it instead (a lot of subtractive processes to the plywood, want to eliminate it)
So what i'm looking for ...
1
vote
2answers
82 views
Effectiveness of LiDAR in manhole structures?
I'm an intern at an electrical utility and I've been tasked with doing a proposal/cost analysis to evaluate whether or not starting a pilot with a company specializing in robotic inspections is worth ...
0
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4answers
116 views
What thickness of steel bar/pipe for home gym?
I would like to build a rack for my home with a pull up bar. I'm leaning towards a steel pipe with a diameter of 42.4 mm, but have no idea how to determine what wall thickness is needed so that the ...
0
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0answers
29 views
Hencky nets on the *interior* of a closed domain
The equations for Hencky nets are usually solved in the exterior of some domain; typical examples are the upper half plane or the exterior of a circle. I would like to know about examples of these ...
2
votes
1answer
69 views
Is the calculated shear strain in a beam, engineering strain or tensorial strain?
Recently I came across a FEM code of a linear deformation beam element, and it made me wonder what is the correct relation between shear stress and shear strain in a beam element.
In the beam element ...
0
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3answers
86 views
How does an arch transfer vertical load?
I am hoping that someone can explain to me how, physically, an arch transfers a purely vertical load (Fy) into a diagonal force to the abutments of the arch.
I understand that the y and x components ...
1
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3answers
60 views
Compute deformation response history from ground motion
I'm reading a book of Anil. K. CHOPRA related to Structural Dynamics, I'm intending to obtain the deformation response spectrum from given ground motion. What I have here in hand is ug(t) ground ...
3
votes
3answers
110 views
I seem to have a fundamental misunderstanding about the double integration method for calculating beam deflection
Here's where I'm struggling
So I've tried to find the expression for deflection of a simply supported beam acted on by 4 point loads at varying distances.
First I balance out the vertical forces and ...
3
votes
2answers
116 views
How exactly do forces transfer in different directions?
If we imagine the load being placed at the top of the below triangle, I realise that the downwards force is transferred into one which goes in a 'south east' and 'south west' direction down to the end ...
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0answers
57 views
On rectangular section beam properties of plate stiffeners
I am trying to understand the expression of the vertical dynamic stiffness $K_T$ and the rotational dynamic stiffness $K_r$ which appears in this paper where they consider a semi-infinite plate ...
0
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0answers
7 views
Question regarding 2D simulation of orthogonal cutting operation on Abaqus
I'm trying to simulate an orthogonal cutting operation on Abaqus, I'm using Dynamic explicit analysis. I have defined my tool as Rigid analytical body and the workpiece is of Ti6Al4V, I have not ...
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0answers
14 views
FEA Simulation of CHASSIS [closed]
What are the most accurate methods in static state for simulation of chassis wrt 4 cases: lateral bending, torsion, head on collision and a zero turn. The problem arises when it comes to applying the ...
0
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1answer
17 views
How placing intermediate stiffeners closer increase strength of girders? [closed]
How does placing intermediate stiffeners closer increases strength of plate girders?
2
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2answers
84 views
Which yield strength should I use in FEA in ANSYS; Engineering or True?
Attached is a figure to illustrate the difference in the value of yield strength as observed from the true stress/strain curve and engineering stress/strain curve. While conducting FEA in ANSYS for a ...
2
votes
2answers
42 views
What happens to load bearing capacity during the plastic region for a ductile material?
Attached is a picture of a typical isotropic ductile material. Can anyone please tell me what happens to the load bearing capacity in the structure in each of the sub-regions under plastic deformation,...
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0answers
25 views
Effect of area spring at slab on column
Say that a simple building is supported by 4 columns , the column sitting on base slab. I assigned some sort of area spring to the base slab. When the area spring assigned is higher, this cause the ...
1
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2answers
57 views
How does the stiffness of semicircular beams connected in series increases?
I am working to reduce the deflection in a cantilever/ dive board at work.$300 mm(L) \times 30mm(B) \times 2 mm(H)$, i.e. it's a rectangular cross section currently.
I can't change the material, or ...
0
votes
1answer
41 views
Why is the beam bending stiffness taken as $EI/L$?
In moment distribution method, the bending stiffness of a beam is taken as $EI/L$. But in these kinds of stiffness tables, the flexural rigidity is usually divided by some power of $L$:
So why is $EI$...
2
votes
2answers
67 views
What Are The Recommended Binding Methods For A Carbon Fibre Chassis Frame?
I'm looking for a simple way (that doesn't require high pressure chambers or state of the art tools) to permanently bind a set of carbon fibre pieces in order to make the frame of a chassis that could ...
0
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1answer
61 views
Thrust force on wind turbine
Could someone explain me how thrust force produces a bending moment on top of the wind power plant's tower?
1
vote
1answer
57 views
What Causes Asymmetrical Buckling in this structure?
I've been playing around with structural modelling on the SkyCiv platform and have created this structure, related to a project I am working on to educate myself.
It is 2m wide, 3m long and 1.5m high ...
0
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1answer
68 views
Why have they stopped having curbs on streets? [closed]
Growing up, roads always used to have a clearly separated sidewalk with a height difference.
All new streets I see have no such curbs/height differences. Instead, it's just one "blur" of ...
3
votes
3answers
140 views
Fun Force Problem - Basic Structure of Two beams supporting weight
I'm very new to engineering and thought I'd start with some basic problems and test them out with my own constructions! I've come up with this fun problem and would love some help solving it.
Say you ...
0
votes
1answer
49 views
How to calculate maximum rpm for a wheel? [closed]
I have a DC motor with a rated rpm of 2750. At max rpm, the rubber wheel that I've attached to it is pulling itself apart (literally, the rubber is being pulled away from the central hub due to the ...
0
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0answers
19 views
Constructing a structure with given constraints
I have a problem where I have a few points in 3D space with given constraints (forces, moments) and I have to create one connected structure which satisfies these constraints. Are there any pre-...
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0answers
61 views
Why are the facades of historic residential buildings in Paris tilted backwards?
In any major city that features an historical center, the list of attractions advertised by tourist guides seldom includes what, in my opinion, would constitute the destination's most important part: ...
1
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0answers
49 views
Why does a system with zero resultant moment turn after temporarily force-tilted?
Say a beam, 3m long from end to end, has a pivot placed at its centre of mass, at half its length i.e. 1.5m. Objects with weight 200N each are placed on both ends of the beam. The system is in ...
4
votes
6answers
573 views
Increasing torsional-stress resistance of an Auger at its motor-shaft joint
An auger is used to move plastic balls and is rotated by a stepper motor. Due to the balls getting jammed sometimes, this induces stress on the auger at the motor-shaft junction and breaks. Images ...
1
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1answer
108 views
PE exam: situations in which two question choices are close to my final answer: how to pick one?
Consider this question:
I solve this eventual question and my answer is 7.29667:
Among the question choices are 7 x 7 ft and <...
0
votes
2answers
31 views
Weight distribution on sliding or “pocket” doors
Does anyone know if hollow sliding/pocket doors have a weight/more dense wood at the bottom of the door to prevent from swinging?
0
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1answer
36 views
How to calculate what size steel RHS to use?
I am welding up a rack to support a distributed load of up to 1000kg, what is the process to work out what steel section size I should use? Many Thanks.
2
votes
1answer
53 views
How do engineers reduce vibration of system with multiple known natural frequencies? How do they design the isolation system for specific frequencies?
I have a system that is pretty much a chamber that needs to sit on the ground. I measured the transmissibility of the chamber vs the ground (output/chamber acceleration over input/ground acceleration) ...
0
votes
1answer
57 views
Design of pinned joint to Eurocode
Above picture is from Eurocode 3: design of steel connections. It gives geometrical requirements for a pin ended member. Looking at situation A, we have the minimum distance $c$ from the edge of the ...
1
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3answers
68 views
Mechanical joint that break at specific force
I am designing a joint which I want to break at a specific force. I want to design a 2 parts connected by a joint that breaks when a certain amount of force is applied and thus prevent any damage to ...
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0answers
37 views
0
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2answers
46 views
Stiffness factor of beam member
If I have a beam with the left end being "A" and it is fixed at that end and the right end being "B" with a roller support, would KAB=3EI/L??
0
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1answer
28 views
Use magnetic levitation to lift a carousel capable of turning 9000lbs [closed]
Allow me to describe my current situation. I have a 18 ft (5.486 m) carousel that is assembled using steel beams that are bent into two circles, an outer and an inner. And there are steel spokes ...
2
votes
2answers
32 views
Small building basement foundation moisture: permeable vs impermeable
I understand that moisture is the enemy of interiors. I know that the standard basement foundation for a house-sized building uses moisture barriers on the outside of concrete retaining walls to ...
0
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1answer
57 views
rust on steel post
Is/will the rust on the steel post in the foreground a problem?
See the post in the background has no rust.
A primer was added and intumescent paint will also be added later.
1
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2answers
100 views
Shear coefficient for an I-Beam
I’m trying to analyze the bending of an I beam using the Timoshenko beam equation and I can’t seem to find the value for the shear coefficient anywhere.
Surely someone must’ve done the work (given how ...
0
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1answer
42 views
Question regarding the extreme wind velocity distribution in Eurocode
Above is the definition of the probability factor from Eurocode 1-4. It is used in context of calculating the extreme wind load on a building. Ignoring some other factors, it is used as follows:
$$v_b ...
0
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1answer
21 views
Should we split a building containing a factory and a storage according to (NFPA 13) code?
I asking for a building that contains a desalination plant and a storage of water bottles (in carton boxes).
Should we split the factory and the storage or not (according to NFPA 13)?
And which ...
0
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2answers
60 views
How is any kind of structural reliability achieved if the probability of annual wind speed exceedance is 0.02?
Above is the definition of fundamental basic wind velocity from Eurocode 1. According to its instructions, wind loads on building are supposed to be calculated based on this velocity. It says that ...
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0answers
18 views
Find orientation of reference nodes in Abaqus
I am constructing a simplified model of a pontoon-supported floating bridge in Abaqus. I have chosen to represent the pontoons as one-noded user-elements defined from the mass and stiffness matrix for ...
2
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2answers
55 views
Why is the yield strength of steel assumed to be less for a thicker element?
The above image is part of table 3.1 of Eurocode steel design standard. Looking for example at the first row (steel grade S 235), we see that there are two values for yield strength $f_y$, one for ...
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0answers
25 views
Boundary Conditions of a Stepped Beam
I would like to ask about the boundary conditions to be considered in a stepped beam. For a cantilever beam wherein the one end is fixed while the other end is free to oscillate along the z-axis, we ...
0
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3answers
89 views
Calculating Load On Winch From a Distributed Load?
I am in the process of building an antenna mast that can tilt from horizontal (down) to vertical (up). The mast (arm) is 360" and weighs a total of 105 lbs. I need to calculate the amount of ...
0
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3answers
77 views
How to calculate beam impact problem
Can anyone help with this Impact problem? It does not seem very difficult but I am having trouble putting all the parts together.
Thanks,
3
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2answers
86 views
How to simplify a truss bridge diagram?
Hello I have this truss structure question. I understand that we need to determine the zero-force members first so that we can simplify the diagram. But I am not sure which one that I need to ...
3
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2answers
847 views
What does “crs” mean in structural engineering / construction?
In the realm of structural engineering, construction, foundation design, what is "crs" when talking about piles/posts? Is it an abbreviation? Does it refer to some sort of size?
Some ...
