Questions tagged [structures]

Questions relating to or the engineering application of a device that must withstand a loading via deflection, stresses, resistance to buckling, or natural frequencies.

Filter by
Sorted by
Tagged with
1
vote
2answers
45 views

Fixed-Free End Column Design

I am currently working on a problem where I have to design a column. The structure I am currently designing currently takes the following form, When designing the column, I know that I have to ...
1
vote
2answers
51 views

2nd Moment of Area of a ring

This is my first question here. I am having trouble finding the 2nd moment of area of a ring with a thickness 't' and radius 'r'. I seem to be a factor of 2 out. What I do is I consider an area like ...
1
vote
1answer
495 views

Can pinned support / pin joint transfer moments in 3D?

What's an authoritative definition of whether the idealized pinned support and pin joint can transfer moments in 3D? Most sources say both of them cannot transfer moments but are apparently only ...
1
vote
2answers
79 views

Stress yield of a specimen, result confusion

I am trying to calculate the static yield stress of a specimen using the 0.2% offset line on a stress strain curve. I found the static yield stress of the specimen to be the number in bold (104.1239). ...
1
vote
1answer
534 views

Determine the strain energy of a bar

I have a Structures question about determining strain energy that I am unable to solve. I have attempted it and I have the answer, I would appreciate if if someone can just tell me where I am going ...
1
vote
2answers
3k views

Transfer of moments in beams with internal hinges

We have a beam with 1 internal hinge just like the picture. We know the internal hinge can not transfer moments between AB and BD. We know the 30 kN force makes some moments on BD & AB. If B (...
1
vote
1answer
3k views

How to find the reaction forces, moments and the displacement of the fixed beam with a link?

The beam is fixed on both ends and there is a link in the middle. There is a force F on the link. My approach to solve this problem: A free body diagram is cut at the link and made into 2 systems. ...
1
vote
1answer
261 views

What is the logic to solve this cantilever problem?

I solved it using the logic that the vertical link of the beam is basically there to make the beam act like a cantilever. So I think it is a cantilever problem. Therefore, $$EI\frac{d^2y}{dx^2}=-px=M$...
1
vote
1answer
1k views

Calculating automotive suspension wishbone loads by considering the structure as a 3D Truss

I am trying to calculate the loads in the suspension components of a typical car double wishbone setup. I have found a thread on the www.fsae.com forum, which seems to be exactly the kind of thing I ...
1
vote
2answers
3k views

Beam with constant load distribution on three supports - force distribution to supports

I have following example (the question is at the bottom): The load distribution $q$ is constant. I add condition of zero bend in center of the beam, $w_B = 0$, and the assumption $F_{RA} = F_{RC}$. ...
1
vote
1answer
58 views

Is it safe to slightly cut the edge of RCC column for passage of pipe in bathroom?

The RCC column was cut in my absence due to passage of pipe for bathroom fittings. The thickness is about 1.5 in. Will it hamper the stability of structure?
1
vote
2answers
281 views

Buildings sinking into the ground

My friend has proposed that the buildings in the images below have been sinking into the ground over time and that they're not planned with basements. He thinks that the bottom of the building was ...
1
vote
1answer
184 views

Stiffness as a function of thickness

Let’s say we have a thin band (made out of PLA, 3D printing material) with a rectangular cross section. In drawing, it would look something like this: Let’s say a force of 15 N is to be applied from ...
1
vote
1answer
105 views

strength of eggshell

It is a known fact that beams and spheres have the ability to carry relatively high loads. Beams are seen in bridges and other structures even since the days of ancient roman architecture. Spheres ...
1
vote
2answers
28 views

How much ballast is required in 110 mph winds to stabilize: a 60 lb., 20’ pole; 3' below ground/17’ above ground, with a 24lb. wind turbine atop it?

I can’t seem to find an answer that doesn’t involve more than a ton and a half of concrete. The manual for the wind turbine reports that the load on the turbine in a 110 mph wind is only 155 ...
1
vote
2answers
177 views

Conveyor Truss Analysis Problem with loading

I've been working on a schematic and its been going beyond my comprehension; so i thought i should consult better structural engineers here. (I'm a fresh Civil Engr Graduate though) i have this ...
1
vote
2answers
72 views

How to find strain in an inclined member of a struss

I'm working through an FEA problem and I'm stuck. Question: How can I determine the strain in member 3 from displacements known at node 3? It's at 45 degrees, I know I should be using some $cos\...
1
vote
1answer
460 views

Reaction forces in a structure

I have the following structure, in which I am failing to calculate the two reactions: Cz (apparently vertical) and Dz, in the roller support of the beam. The beam length is 7.5 m, the reactions Az, Cx,...
1
vote
2answers
696 views

Steel Continuous Beam Structural Diagram

Here's an image of my structural plan that my group and I are designing for a university assignment. It is a 7-story steel structure with bracing at the two ends and at the verticle core near the ...
1
vote
1answer
4k views

How to calculate effective section modulus of a slender section?

Hi how to calculate the effective section modulus of a class 4 section using Eurocode 1993? Can someone show me an example? I tried searching online but cannot find anything useful. My main problem is ...
1
vote
1answer
619 views

Which is the best way to construct a trapeziun dome with a 76' diameter

When building a trapezium dome, is it better to construct the dome row by row or by first making a vertical arch? Is some form of bracing required?
1
vote
1answer
39 views

Question on the determinacy of frame structures

I have been working on a program to solve frame problems, and I have used the following formula for determining whether a frame is statically determinate: $$RD=3m + r-3j-s,$$ where: $m$ is the number ...
1
vote
0answers
18 views

Secure loads to gearbox shafts

I have a sculpture that is designed to rotate over 3 axes at max. 30RPM and is mounted on an aluminium disc. My plan is to use 3 of these geared steppers and secure the sculpture to the Z-axis shaft, ...
1
vote
1answer
32 views

column yielding under earthquake

In the buildings designed with strong column weak beam concept, the columns will remain elastic, their plastic deformation will be limited. but this is not true at the base of the building. i mean i ...
1
vote
1answer
54 views

Mounting outdoors camera using aluminum 5052

I designed a simple U shape 2mm sheet metal bent mount for a 4kg outdoors CCTV camera. The mount was accidentally produced from 5052-H32 Aluminum instead of 6061-T6. Is it common to use 5052 ...
1
vote
0answers
77 views

Calculating diameter of steel rod required to not bend over a given length

I want to use steel (or other material) rods to support weight over a 900mm cavity. The weight that needs to be supported is technically unknown, but I'd specify some rough guidelines as: 100KG (max) ...
1
vote
0answers
31 views

Research based bridge project? [closed]

I am a fourth year civil engineering student at IOE pulchowk, Nepal. In our syllabus one practical based curriculum called Project Engineering has been added. I, along with 5 friends, are interested ...
1
vote
0answers
34 views

What does 'Analysis Model Value' in NASTRAN optimization mean?

I am new to MSC NASTRAN and PATRAN. I am running a simulation on composite laminate optimization. While creating the design variables for the study, I noticed that there is a parameter called '...
1
vote
0answers
65 views

Calculating the Structural Forces Required to Support a Robot on an Overhanging Beam

this is my first time posting on here and I have a question regarding the structural properties a beam will need in order to fulfill some requirements we have for our robotics team. The scenario is as ...
1
vote
0answers
327 views

Beam element stiffness matrix for variable area cross section with mass and shear center not coinciding

I would like to find the full (12 by 12) Timoshenko beam element stiffness matrix for a variable cross section with mass center axis and elastic center does not coincide. I have the full stiffness ...
1
vote
0answers
68 views

How to design a shelving unit out of McMaster Carr Struts? [closed]

I apologize for the complete beginner question. I'm an Undergraduate Research Assistant trying to design a shelving 8'tall by 10' Long, 4' wide shelving unit to support about 200 lbs. I'm designing ...
1
vote
0answers
30 views

How to support height extender on a rail?

I've got an 1/8" thick steel rail with 1.5" diameter and 15' in length sitting on two 5/32" thick steel rails with 2.5" diameter and 100" in length 14' apart: I want to add a diagonal support for a ...
1
vote
0answers
46 views
1
vote
0answers
37 views

Check of a nominaly pinned steel joint

I am interested how to check a nominally pined joint. Especially how to check its rotational capacity and whether i can define it as nominally pinned in structural fem model. I understand that there ...
1
vote
0answers
26 views

How to calculate a global strain from a field disitribution

For an arbitrary articulated structure subject to non-affine (non homogeneous) deformations, the components of the strain tensor are defined locally. Is there a way to calculate a numerical strain ...
1
vote
0answers
33 views

Pressure-volume relation of thin-walled shell [closed]

Attempt to edit into a more specific question as suggested by moderator: I would like define the shape and material properties of a 3D thin-walled shell/membrane-like structure (for instance a baloon)...
1
vote
0answers
67 views

How should I position two shelf supports for the minimum deflection? [duplicate]

The above is the shelf that I'm intending to put up. It will have two symmetrically placed supports. This is probably a simple question that really should be answered in all DIY shops but... ...
1
vote
1answer
6k views

How much weight can this stand hold?

I got this stand from a friend of mine years ago. Its unbranded. I want to use it to hold a 55 gallon fish tank which can weigh about 456 pounds to 622.5 pounds. How can i calculate a estimate of how ...
1
vote
1answer
357 views

Calculate mobile base weight to support adjustable arm

I want to calculate how heavy a mobile hydraulic post table base must be to support an adjustable monitor arm and monitor. Monitor (iMac) Specs: Height: 20.3 inches (51.6 cm) Width: 25.6 inches (65....
1
vote
0answers
537 views

Suitable tube materials for making a light-weight, heavy-load bearing structure [closed]

I am looking to build a detachable hammock stand structure for camping. I was originally thinking about making one out of PVC but I am in the UK and it isn’t cost effective as it looks like it needs ...
1
vote
0answers
867 views

best way to reinforce existing structural header?

House remodeling. I need to enlarge (from 7 to 10-12 ft) and shift (about 5ft sideways) an existing header where one passes between rooms. On one side, the header has 2x8 ceiling joists nailed to ...
0
votes
1answer
128 views

Deflections Of Statically Indeterminate Structures

When analysing and then designing a rigid jointed, statically indeterminate structure, I can solve for all the forces and moments using the Hardy Cross (Moment Distribution) Method. However, I am ...
0
votes
2answers
159 views

Why we don't use fillets while making buildings?

Why don't we use fillets when making buildings and houses (i.e why do we leave the edges sharp?)? Does stress concentration factor not matter in making structures? I am talking about the building ...
0
votes
2answers
29 views

Earthquake time history analysis

Time history analysis of earthquakes for structures, is a NON-LINEAR dynamic method correct? Then why is there also something called "LINEAR response history analysis"? What is the difference of this ...
0
votes
1answer
447 views

Using strain energy to calculate deflection

I have a solids problem I cannot solve, I have the answer and I have attempted the question. I just need to know where I am going off track, (perhaps there was an issue setting up my deflection ...
0
votes
2answers
1k views

How to calculate a structure's ultimate load [closed]

Sorry in advance if this question is excessively noobish or seems lazy. I have no engineering background and am unsure where to get started tackling this problem. Links to resources that could put me ...
0
votes
1answer
63 views

Maximum I-beam girder S12x31.8 span

Does 200lb/in of load on a S12x31.8 over 15 feet seem reasonable? I'm having a tough time trusting the numbers. Two story house with an attic as below. Dotted lines show load bearing walls W1 and W2. ...
0
votes
1answer
83 views

Drop Panel Design Above Columns?

How to design a drop panel at a column in case the column above is rotated or not aligned to the below column (see image below), the code that i am using is the ACI Code if any reference for the ...
0
votes
1answer
74 views

Is a bridge more stable on concrete or soil?

I understand that foundations are used in structures to support and spread the weight of the bridge over a large area. However I am struggling to understand why certain materials such as concrete are ...
0
votes
1answer
121 views

Torsion on thin walled members

Is the formula $T=2qA$ valid for both open thin-walled and closed thin-walled members, where $T$ is torque, $q$ is shear flow, and $A$ is the area?