Questions tagged [structural-engineering]
Questions related to the integrity, design requirements, or analysis of structures.
1,031
questions
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welding pipes with an angled fillet weld
I am designing a tractor implement for harvesting root crops. Similar to this one here, but stronger construction with cutting discs in front of it to prevent weed jam. These images will help you ...
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2answers
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What happens when we remove the load, in different regions of the stress strain diagram of mild steel?
A: Proportional limit| B: Elastic limit| C: Upper YP | D: Lower YP
Let us say, the gage length was 100mm (random, just for the sake of understanding). I know that if I unload the body anywhere between ...
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4answers
1k views
What happens from B to C in this stress strain diagram of mild steel?
Image Source: https://mechtics.com/design/strength-of-material/stress-strain-curve-for-mild-steel-with-defination-of-stress-and-strain/
I know that A is the proportional limit, B is the elastic limit. ...
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2answers
84 views
Could the St. Louis Gateway Arch be used as a support structure for a giant vertical axis wind turbine?
I am curious to know if the St. Louis Gateway Arch would be strong enough to act as a support structure for a giant vertical axis wind turbine.
I way I am envisioning this being constructed is that a ...
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0answers
22 views
Supporting a piece of 5 * 3 foot baltic birch plywood to prevent bending
I'm working on converting a van to a nice living situation. This is my first post in the engineering forum; hopefully, I've gone into sufficient detail with adequate clarity.
In the back of the van, ...
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3answers
57 views
Why tensile test specimen is enlarged at its ends?
The tensile test specimen used for tension test has an enlarged cross sectional area at the ends. The sources I'm referring to, suggest that this is the case so that the failure occurs in the central ...
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3answers
63 views
Column with Eccentric Load
Need help determining the bending moment acting on the column. At the top of the column, the cantilever tube is slid into a shorter piece of tubing. The shorter piece of tubing is welded to the ...
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3answers
46 views
Why we needed to relate internal resistive forces with area (stress)?
When we load a body, say a prismatic bar, axially, internal resistive forces are developed within it to oppose the elongation or compression. What was the need of relating these internal resistive ...
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2answers
32 views
Clarification on Aluminum Design Manual
I am using the aluminum design manual equations to design an aluminum column that fixed at the base and free at the top, so fixed-free end conditions. Section C.3 of the Aluminum Design Manual says to ...
2
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0answers
29 views
Bar released from upright position rotates about a lower hinge before being caught by a steel cable, how to calculate the tension on the cable?
I wish to check the safety factor of a steel cable that I've designed to catch a heavy bar that rotates freely due to the gravitational force acting on it.
From the upright position, I'm assuming that ...
2
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2answers
54 views
What happens to the maximum force in bar under bending when its cross sectional area is decreased?
Consider a rectangular cross sectional beam for instance with dimensions a = 1 mm and b = 1 mm, fixed at one end and transverse force at the other. I will get the maximum stress at the farthest away ...
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3answers
33 views
Question about shear force on the beams
Can someone please point me in the right direction.
I am a newbie when it comes to statics. I am trying to understand the following diagram.
Why on the left side of the beam section, the moment is in ...
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1answer
58 views
Max Stress on Weld
Part is welded to a plate, based on the below free body diagram how would I determine the max stress in the weld? It seems half the weld is in tension and the other half is in compression.
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2answers
27 views
Reaction forces on a three support continuous beam with two of them requiring compatibility equations. Superposition method done wrong!
I need to analyze a continuous beam of length L and three supports: A (at x=0), B (at x=L/2), and C (at x=L). An applied load P is applied at x=3L/4. Now, at A, the continuous beam is bolted to a ...
2
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1answer
59 views
Rammed Earth Building
I am estimating the amount of materials required to make a rammed earth building and I can't find anything related with the foundation of rammed earth building and about two-storeyed rammed earth ...
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0answers
12 views
Component Additive Method for fire ratings: (why) are cement backer units not rated?
IBC 722.6, along with Harmathy's Ten Rules (written down in AWC DCA4, among other places), provide a method, known as the Component Additive Method, for computing the fire ratings of light-frame wood ...
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1answer
29 views
How do I calculate the strength of a carbon fiber tube?
I am not a mech engineer and have been struggling with this for a while, I feel like it is pretty straight forward but I'm missing something.
The problem is a horizontal tube that is supported at one ...
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2answers
99 views
What is the purpose of these "safety" ledges on this Asian skyscraper?
While watching a video of a crazy person jumping around on buildings in some Asian country in a death-defying manner, I noticed these odd "safety" ledges outside, with nothing preventing you ...
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2answers
66 views
Will my floor safely support 2000 lbs of live load over a 36"x36" area? [closed]
I'm trying to find out if my floor will safely support a live load for an aquarium in an area that is approximately 36" by 36". the total weight would be about two thousand pounds including ...
0
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1answer
58 views
Are there any ways to know whether the element has failed under loading, while knowing only limited properties?
I opt to check whether a precast concrete wall (no reinforcements, only concrete) withstand both vertical and lateral loading condition but the only properties I know are the Young's Modulus, density, ...
0
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4answers
117 views
How are these bricks being supported?
My question is how can all of these bricks be supported by the thin columns on either side? How can there be that much empty space under all of the bricks that the arrow is going through? Looking at ...
3
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1answer
122 views
Can river rock be used as a subbase in place of crushed stone?
I live in an area that has an abundance of river rock and a shortage of crushed stone. Can river rock be used in place of crushed stone as a sub base for foundations, roads, etc. or does the ...
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1answer
50 views
How to assess the stiffness of a hollow steel section joint?
Hollow steel sections are used often in trusses:
I've been taught that the advantage of a truss structure is that it can be stiff without any of the members being under bending moment. This is an ...
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2answers
75 views
What's the minimum number of required wooden pieces to make this door structually solid?
This is the basic requirement of the wooden door frame:
The requirement is to make sure that the door frame does not skew or deform.
Questions:
What's the minimum number of wooden pieces to be added ...
2
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2answers
54 views
How to calculate the required prestressed jacking pressure to apply to a pre-tension concrete beam?
How does the fabricant of prestressed pre-tensioned beams calculate the equivalent pressure in the hydraulic jack (in bars) to the design prestress force (in kN)? Are there factors to multiply like a ...
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4answers
76 views
A question on resonance
This is to settle a debate.
I was working on a scaffold next to a building, as the wind blew, the scaffolding would sway. As I stood there I was trying to maintain my stability, but my movements ...
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0answers
14 views
compute nodes and members according to stiffness matrix of truss (inverse the direct stiffness method)
I am familiar with the direct stiffness method (truss), and programmed it from scratch in Java.
The member stiffness matrix is determined by any link (member) and
the nodal coordinates.
The global ...
2
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0answers
37 views
How to estimate effective area of contact between rough surfaces as function of surface roughness
The engineering problem that I am trying to solve is the following: I have two elements of a magnetic circuit that I must keep in contact through threaded fasteners. The primary objective is to ...
1
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2answers
49 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
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2answers
90 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 ...
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4answers
130 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 ...
2
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0answers
53 views
Hencky nets/slip-line fields on the the interior of a closed domain
This is a crossed post.
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 ...
2
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1answer
80 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 ...
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3answers
110 views
How does an arch transfer vertical load? [duplicate]
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
64 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
127 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
133 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
61 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 ...
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9 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
18 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
126 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
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2answers
43 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
27 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
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1answer
84 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
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2answers
70 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
74 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
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1answer
59 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
71 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 ...
