All Questions
Tagged with aerospace-engineering structural-engineering
15
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How does one calculate the aerodynamic pressure on a spacecraft during Max Q?
Just as lift - off of a spacecraft commences, that spacecraft undergoes aerodynamic pressure. After a certain point, the spacecraft reaches Max Q or maximum aerodynamic pressure. I do know that Max Q ...
- 101
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25
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I'm Missing Something on Problem 3 in Section A5.4 of Bruhn's Analysis and Design of Airplane Structures
I've been working through the 1943 edition of Bruhn's Analysis and Design of Airplane Structures. I found an archive.org pdf version of the 1948 edition that includes answers to select problems, as ...
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111
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Why are stress intensity units MPa√m
The units of stress intensity are usually taken as MPa√m. Cracks are usually measured in (mm), could someone please explain why this convention is used an not consistent SI units
- 1
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67
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Does the weight of a pilot exponentially affect the necessary weight of human-powered aircraft?
The MIT Daedalus, a human-powered craft, weighed about 31 kg. This was significantly lighter than its pilot during its record setting trip, though I can't confirm the pilot's exact weight. Still, this ...
- 3
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591
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How to design the thickness and diameter of a cantilever beam in bending for both composites and metals?
The goal is to find the optimum values of the diameter and the thickness of the circular cross-section of a cantilevered beam in bending, with the lowest weight (cross-sectional area). The main ...
- 23
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3
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2k
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Why does the upper wing skin fail in buckling and lower wing skin does not?
I am aware of the fact that the buckling is mainly caused in the regions of the specimen which are in compression. But the wing skin doesn't take any axial loads and is used to resist shear, atleast ...
- 1,365
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133
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In a nonlinear static two-step subcase, why does the load step decrease after the first step?
I am using MSC Nastran for nonlinear static analysis (sol 400).
Step 1 contains a small perturbation load laterally on a thin-walled cylinder.
Step 2 contains a very large compressive load.
...
- 67
1
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359
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For arc-length method in nastran, how to analyse post-buckling behaviour with load decrease
I am currently trying to model the buckling behaviour of a cylinder using sol 400 nonlinear static analysis using Nastran. I am using the arc-length (modified Riks) method as apparently it can ...
- 67
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2
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107
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What should be the material and thickness of front pillars to stop car (~1,847kg and ~262 km/h) without killing the driver?
"Tesla Model 3 owner died in a tragic accident with a semi truck. The Model 3 went under the truck’s trailer resulting “in the roof being sheared off as it passed underneath,” which is known as a “...
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2
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122
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What does it mean that the mass of a propellant tank is at premium?
I am reading the rocket propulsion elements book by sutton and I came across the following statement: "Because the propellant tank has to fly. its mass is at a premium and the tank material is ...
- 115
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963
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Meshing Complex models in abaqus
I'm trying to mesh a model of a morphing wing in Abaqus and have been running into issues. It was recommended that I partition the model into smaller parts, but it seems that the more I try to ...
- 11
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569
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What is the straightest, longest and strongest pole that could be launched into space?
Which of these poles would be straighter and stronger then the others?
These are some poles that are compacted making them possible to send to space. Sending a single solid pole .5km long will not be ...
user4139
1
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0
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564
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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 ...
- 111
-7
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3
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430
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Can a blimp enter Mar's atmosphere as a glider?
I saw a high altitude jump where someone had exceeded the speed of sound before the air slowed him down enough to deploy a parachute. While inflated in space could a blimp enter the atmosphere while ...
user4139
5
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3k
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Logic behind location of shear centre
When we apply a vertical shear force Sy and the structure is symmetric about x axis, then why is it logical to have the position of shear center at the location of intersection of line of action of ...
- 247