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7 votes
Accepted

Short circuit in welding

No, this is not classed as a "short-circuit". This is a circuit with a designed current flow - ie a 60 to 150A range is common... A "short-circuit" is a circuit where the current flow is not ...
Solar Mike's user avatar
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4 votes

I want a shockproof table for a model train. That is, protection from physical jolts, not electrical volts

Build two tables. The outer table will have a hole in the middle and only hold the glass plate. There should be about 10 cm of free space between the tables. The train will be placed on the inner ...
jpa's user avatar
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2 votes
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Comparing 2 shock scenarios with different magnitudes and times

For car exidents there is a meassure, which is called Head Injury Criterion. It is a measure to estimate the possibility of an head injury during a car accident. The HIC for the time interval $t_1,...
MrYouMath's user avatar
  • 1,036
2 votes

shock absorbing rigid joint

If all three things labeled "joint" in your drawing are hinges, I don't think the spring will do anything at all. You don't say what you are trying to measure here, but the design doesn't seem to ...
alephzero's user avatar
  • 12.5k
2 votes

What height is needed to drop a 72 kg mass to impart a 5000g shock onto a test piece

it depends on how far your steal drop table travels after hitting the sample, the less travel the greater g. The kinetic energy of the drop table when it hits the sample is $$KE=1/2mv^2 \quad and\ v=\...
kamran's user avatar
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2 votes
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Are the modal participation factors bounded for shock response spectrum analysis?

In the section "The Multiple DOF System" the Comsol document says It has been assumed that the mass matrix normalization of the eigenmodes is used and that the damping matrix can be ...
alephzero's user avatar
  • 12.5k
2 votes

stress wave propogation in metals

I think this is more a comment than an answer, but I have too small reputation to comment (poor me!). Summarizing, you are asking: how dynamic loads propagate inside a structure? I would underline ...
Fabio M's user avatar
  • 41
1 vote

What causes damage to my drone when falling down?

A change in momentum is called an impulse which is equal to force applied over time. It's not the change in momentum since the change in momentum to reach zero speed from a given speed is the same ...
DKNguyen's user avatar
  • 5,481
1 vote

Shock loading stresses due to falling: what strength to use for acceptance criteria?

Your static deflection is way too low. let's consider a 1-inch length of your angle for a basic check. Assuming steel E=29000ksi $$I=1*0.38^3/12=0.00457 in^4 $$ $\delta = \frac{wL^3}{(3EI)} = \frac{...
kamran's user avatar
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1 vote
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Is shock spectrum always obtained for an undamped single degree of freedom system?

Not necessarily, many shock response spectra are created for systems under the impulse of a shock with damping. However many codes allowing seismic design using the response spectra with an estimated ...
kamran's user avatar
  • 22.2k
1 vote

shock absorbing rigid joint

Here is a simple design as a starting point for you to modify according to what are your constraints and what are the data that you need to collect. On the track of the wheel, there is a graduated ...
kamran's user avatar
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1 vote
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Shock/Isolation mounting under tension

Use U brackets with the tops of the U welded to the table underside and flatten the bottom of the U to provide the support - then the vibration mounts can be in compression also side supports can be ...
Solar Mike's user avatar
  • 15.6k
1 vote

I want a shockproof table for a model train. That is, protection from physical jolts, not electrical volts

How much money do you have? You could buy, for example, an air-suspension table such as those sold for optical lab work. You could make the table out of half-inch forged iron and bolt it thru the ...
Carl Witthoft's user avatar

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