Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [structural-engineering]

Questions related to the integrity, design requirements, or analysis of structures.

0
votes
0answers
20 views

Machine Frame Design

I have a query about the design of machine frames. For example, if I have a steel frame that is supporting the load of the mechanism above it. First, I analyse and find all the internal axial and ...
3
votes
2answers
31 views

Why do some guyed towers come to a point at the bottom?

Why do some guyed broadcast towers come to a point at the base. It seems that it would be more stable if each vertical bar was anchored separately rather than being balanced at one point.
1
vote
1answer
21 views

Correct sizing of fastener for console

Following situation: I need to mount a console holding a load to the edge of a 25cm concrete plate. I want you to check my reasoning. This is the situation: My thinking is: The load is 170kg, which ...
2
votes
1answer
61 views

Cooling tower for nuclear power plants

Cooling towers for nuclear power plants often have the shape of a hyperboloid. At first glance, I thought that an obvious reason for this would be the smaller sectional area, meaning the tower would ...
2
votes
1answer
31 views

What really is so special about principal stresses or stress invariants?

At any point inside a structural element under deformation, we can always find three planes such that when we define a coordinate system with basis vectors lying on those planes, the shear stresses at ...
2
votes
1answer
26 views

Why is tensorial shear strain half of engineering shear strain?

Small deformation shear strain $\gamma$ in engineering can be expressed as $$\gamma_{xy}=\alpha +\beta ={\frac {\partial u_{y}}{\partial x}}+{\frac {\partial u_{x}}{\partial y}}$$ where $u$ ...
-1
votes
0answers
13 views

Floating shelves: limited support width

In a remodel we have lost a main storage cabinet in favor of keeping an open view through the kitchen. I would like to consider open “floating” shelves but have only a 4” support on which to mount ...
1
vote
1answer
33 views

Calculating area moment of inertia for a beam with underslung plate?

In a number of designs, a beam will have an underslung welded plate attached, as shown below: In this sketch, a symmetrical standard steel beam/column of dimensions H1 x B1, with web and flange ...
0
votes
1answer
37 views

Software for automatic building floorplan calculation / drawing (packing problem)

An apartment yield analysis is a set of draft drawings in which the optimum residential apartment layout and resultant yield is calculated for a given building site, taking into account development ...
1
vote
0answers
36 views

Rotational bending in Timoshenko beam theory

The Wikipedia article on Timoshenko beam theory says: The model takes into account shear deformation and rotational bending effects, I am familiar with shear deformation, but what is meant by "...
1
vote
0answers
15 views

Structural analysis + thermal expansion using ANSYS static module

I am attempting to model a steel sample subjected to combined mechanical and thermal loading. The thermal loading can be quite elevated, where reduction in the elastic modulus will occur. Does anyone ...
2
votes
3answers
79 views

How do I calculate the member forces of a truss when external force acts on the member (not joint)?

Given a three member truss structure shown here: How do I find the vertical and horizontal displacements at M? Assume all members are elastic and E,A, I and constant. I start with finding the ...
1
vote
0answers
11 views

Etabs Semi Rigid Diaphragms

In Etabs, if I model a building with semi-rigid diaphragms assigned to the floors, the floors will now transfer gravity loads when default meshing is assigned (as compared to rigid diaphragms ...
1
vote
0answers
28 views

Why can we ignore transverse shear stress in thin beams?

In a text I'm reading on Euler-Bernoulli beam theory it is said that as the beam is assumed to be thin, the effect of transverse shear stress is ignored. If the beam is thick, we need to use ...
19
votes
3answers
4k views

What is the purpose of building foundations?

According to many sources, one of the purposes of building's foundations is "To distribute the weight of the structure over large area so as to avoid over-loading of the soil beneath." (Wikipedia) On ...
0
votes
1answer
18 views

Selection of Aluminum (or steel) tubing dimension based on uniform load on supported beam

I am installing shades on a section of deck. The shade will be made of sections of fabric (which will let some wind through), but I assume a solid section. Dimensions are 3.5ft*4ft = 14ft^2 = 1.3m^2 ...
0
votes
1answer
27 views

Window header sizing: total load on header

I have a flat roof (dead load = 20 psf, live load = 30 psf) spanning 11 feet with a 2 ft. overhang. I'm trying to calculate the total load in plf on the header marked as X. Is this calculation ...
2
votes
0answers
19 views

computer algorithm to calculate shear center

Without using FEA, is there a computer algorithm or numerical method available to calculate the shear center of any 2D geometry if the following are known: geometry of the individual components of ...
1
vote
1answer
23 views

2D Solid - Axisimmetric - Missing properties and material

Goodmorning, I'm trying to understand how 2D solid elements work. I want to study the local buckling of a simple aluminium pipe with thin walls. From what I understood, I can use 2D solid elements ...
1
vote
1answer
55 views

Maximum tensile and compressive stress in a T-beam

Where does the T-beam come from? There's just a straight beam resting on two supports. And where do 10 and 80 come from? I am so confused.
1
vote
1answer
41 views

Determining the direction of internal forces in a truss

I am learning the method of joints, but there's no explanation on how to figure out the direction of internal forces in my course. How do you know that BA is tension and BC is compression?
0
votes
1answer
34 views

Pergola Span and Support Modification

I purchased a pergola kit and realized afterwords I'm not happy with the placement of the center post. If possible I'd like to eliminate it. After searching for a while I haven't been able to find ...
4
votes
1answer
117 views

Is Scrooge's giant glass dome feasible in real life?

In an Uncle Scrooge (or Scrooge McDuck, not sure of the translation here) comic named "Treasure Under Glass", Scrooge orders a giant glass dome to be manufactured in order to aid his endeavours ...
0
votes
1answer
86 views

The buckling stress and yield stress

The buckling stress, using the Rankine and Gordon Equation or the Perry-Robertson Equation, is always less than the yield stress of the material?
1
vote
1answer
50 views

How to find the diameter of bolts in a flanged joint?

So I'm given this question with the following diagram: Two sections of a pipe are joined in a flanged joint as shown in the Figure below. The difference in pressure from interior to exterior is 2 MPa....
2
votes
2answers
40 views

What is the meaning of line and points in the schematic of a polymer

In the engineering material book. It shows the following figure The following is the text to depict the picture "The origin of rubber elasticity is more difficult to picture than that of a crystal or ...
0
votes
2answers
42 views

Is a 1/8" AR400F steel plate strong enough, for 4,000 lbs?

I have a Ford F350 cab & chassis and a gooseneck trailer. For the gooseneck hitch I want to use a steel plate. The steel plate will be BOLTED to the frame, above the rear axle And the gooseneck ...
0
votes
0answers
19 views

About method of work and Energy or Clapeyron theorem

I'm having some difficulty to understand the work and Energy method (aka Clapeyron theorem), especially with different loads. Could you please help me to fix this problem, because I found different ...
3
votes
3answers
105 views

What are the possible implications of the heating of the structural stonework of Notre-Dame cathedral during the fire?

Yesterday, Notre Dame cathedral caught fire. The roof and the central spire were destroyed and some of the stonework was subjected to high temperatures for an extended period. What are the likely ...
0
votes
0answers
30 views

Determination of Warping Function for Thin-walled Multi-cellular Beams

I am trying to find warping function $\mathcal{T}$ for a thin-walled multi-cellular beam. There are four rectangular cells. The governing differential equation for $\mathcal{T}$ is Eq. 8.98 as shown ...
8
votes
3answers
142 views

What is the umbrella-like thing surrounding this new structure?

Recently this water tank was constructed (poured concrete). (I presume it is a water tank, as they laid blue plastic/PVC water pipe, perhaps 24 in. dia., in the vicinity at the same time.) After the ...
0
votes
0answers
37 views

Traction Force or Reaction Force

I am doing an FEA of a link plate of a chain drive system. the plate is subjected to traction force at one pin joint this particular link is in contact with the sprocket. it is also in contact with ...
0
votes
0answers
25 views

Static balancing of link mechanism

So I'm trying to get to the condition as shown in the picture below, where it says that if we have zero free length springs and k1r2=k2r1, then any configuration (pose) of the link is in equilibrium. ...
3
votes
2answers
201 views

Strength of face-nailed connection for stair steps

I'm building a loft ladder with alternating-tread steps. The stringers are 2x6 White Spruce, and I'm hoping to build the steps out of the same material. The span for the steps is 21". Code requires ...
0
votes
0answers
23 views

How to calculate *minimum* length of base/return required to stabilize an angled vertical?

Trying to design a stable jewelry display. What is the formula to calculate minimum length of base/return required to stabilize an angled vertical rectangle? Or (because that formula is undoubtedly ...
0
votes
2answers
64 views

Why not build container ships from plastic?

This may sound crazy but bear with me. I was thinking about why cargo ships are built from such heavy material as steel, while smaller boats are often made of plastics. I know cargo ships carry a lot ...
0
votes
0answers
23 views

Can I use fixed support for a frame?

Can we use fixed support at columns in a frame? Because If we do so , there will be 2 moments when we will cut the section.
0
votes
1answer
33 views

Shock/Isolation mounting under tension

I want to secure a box (roughly 20kg in total) that contains electronic equipment to the underside of a flat steel structure. We can weld onto the underside. The steel structure has a high chance of ...
1
vote
1answer
47 views

Can a plate under bending be designed using its plastic section modulus?

I am designing an end plate connection. My lecture notes show its bending capacity is calculated using elastic section modulus. For class 1 I-beams, we can use its plastic section modulus. I wonder ...
0
votes
0answers
33 views

Need help with FEA bar analysis problem

I'm trying to solve this which is to find the total deformation of the bar. I'm trying to implement the finite element approach, but I am getting way too large of numbers. Here is what I did in ...
0
votes
1answer
37 views

Aluminum tube frame to support 2300 lbs water tank

I want to build an aluminum tube frame strong enough to support a 2300 lbs water tank. The dimensions of the frame would be 28 " wide, 72" long and 16 inches tall. My intention is to use 2" x 2", 1/8 ...
5
votes
1answer
50 views

Should the corbel angle always be estimated as 60 degrees in masonry construction, or is there a formula to use instead?

In educational construction material as well as engineering publications, the corbel angle for significant excess loads, and also for substantial openings, in an ordinary brick wall is usually ...
0
votes
0answers
26 views

Why would a SMD (spring mass damper) model of steel break down?

Under what conditions would steel be able to be modelled as a 3D SMD model, and under what conditions would the model break down?
0
votes
2answers
56 views

Rotational and translation DoFs in structural mechanics

I'm a computational person, and I don't quite understand how rotational DoFs are manifested in the linear elasticity equations. I understand the translational DoFs are simply the displacement ...
2
votes
2answers
54 views

Need Help to Remove Sway from Steel Post + Glass Panels

I have spanned ~15' with 2x 10mm tempered glass panels. They're connected in the middle with a 1.5" x 1.5" 16-gauge, 316 stainless steel post filled with concrete. This post has a 316 base welded on ...
2
votes
1answer
76 views

Which way of joining is stronger?

I have to build a box to extend the length of a projector bracket: The projector bracket weighs 7kg and has an arm of about 500mm. The projector weighs another 5kg. The box has a depth of 140mm. ...
1
vote
1answer
32 views

Member weight in a planar truss?

So I'm given a question in which a Truck drives over a pratt truss bridge. In the question the truss is in 3D. I'm given: 1)The loads from each axle of the truck 2)The weight of each member in the ...
1
vote
2answers
79 views

The internal normal force, shear force and moment

How do I determine the internal normal force, shear force and moment at the point C? $V_c = 0$, $N_c = 0$ and $M_c=3.75 kN/m$ I have already done this: Where is the problem?
0
votes
2answers
37 views

How can I keep a free spinning range finder pointing down?

I have a rod mounted inside of a 2x4 that is allowed to freely spin inside of its hole. Attached to that rod's head is a range finder. I want the rod to reliably point down at the ground at all times ...
2
votes
2answers
42 views

Exact anlytical solution for beam-lifting problem constrained by crane capacity

I have been trying to calculate the analytical solution for the following problem but have not succeeded to reach an exact solution. Can anyone propose a way? A concrete beam is to be lifted by two ...