8
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 ...
- 16k
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 ...
- 1,943
2
votes
Accepted
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,...
- 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 ...
- 12.6k
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 $$KE=1/2mv^2 \quad and\ v=\...
- 22.8k
2
votes
Accepted
Are the modal participation factors bounded for shock response spectrum analysis?
In the section "The Multiple DOF System" the Comsol document says
It has been assumed that the mass matrix normalization of the
eigenmodes is used and that the damping matrix
can be ...
- 12.6k
1
vote
What causes damage to my drone when falling down?
A change in momentum is called an impulse which is equal to force applied over time. It's not the change in momentum since the change in momentum to reach zero speed from a given speed is the same ...
- 5,629
1
vote
Shock loading stresses due to falling: what strength to use for acceptance criteria?
Your static deflection is way too low.
let's consider a 1-inch length of your angle for a basic check.
Assuming steel E=29000ksi
$$I=1*0.38^3/12=0.00457 in^4 $$
$\delta = \frac{wL^3}{(3EI)} = \frac{...
- 22.8k
1
vote
Accepted
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 ...
- 22.8k
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 ...
- 22.8k
1
vote
Accepted
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 ...
- 16k
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 ...
- 4,259
Only top scored, non community-wiki answers of a minimum length are eligible