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Questions tagged [shock]

21 questions
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2 answers

Are there standard vibration and shock specs for shipment of a product?

Suppose I want to ship my product via UPS, or whatever other professional carrier service. What vibration and shock forces should I design my product to withstand? And how can I effectively test my product against those forces?
Stephen Collings
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1 answer

Explanation of supersonic flow differences between a 2D wedge and a 3D cone

I know that in case of wedge we have a 2D behavior which creates a discontinuity across the shock, but I am unable to understand why this discontinuity is not present in the case of a conical surface. I have a vague idea that the continuity equation…
Manish
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3
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2 answers

Spring - Piston with different extension and compression rate

I am in need of a device that extends freely without much resistance but compresses slowly. I can provide a door closer analogy.The door should open fast but close slowly.... Do you think this can be achieved? Basically my idea is to come up with a…
raj'sCubicle
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3
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1 answer

Short circuit in welding

All I know about welding is it is a technique in which electrode is connected to one terminal and the gripper connected to workpiece is in connection with the other terminal. As current passes and when the electrode is touched to the workpiece,an…
Shwetha
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2
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1 answer

Are the modal participation factors bounded for shock response spectrum analysis?

Recently dug myself into the theory of shock response spectrum analysis, but one thing is not clear for me. The theory says that the peak response of the structure can be calculated as the product of the participation factor and the pertaining point…
G.David
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2
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1 answer

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

We are evaluating a design in which a fall-arresting safeguard would be subject to a shock load in the event of a catastrophic failure of a different component, which is required to meet compliance with our design standard. We believe that the…
Luke
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2
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0 answers

What are the hypersonic Normal shock relationships?

I am learning about hypersonic flow now and there seems to be a lot of discussion about the oblique shock relationships as the Mach tends to be very large. I was wondering what happens to the normal shock relationships as the Mach number tends to be…
user1234
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2
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2 answers

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

I have an N-scale model train (N-scale is about half the size of HO scale). It's so small I could set up an entire layout on something the size of a coffee table. Put a glass top over it and I could use it as a coffee table. Problem is that people…
Chuck Pergiel
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Entropy in Euler equations for compressible flows

In compressible Euler equations, everyone knows the energy equation can be written as $$ \dfrac{Ds}{Dt} =0 $$ which implies the entropy is constant along the path line. However, we have shockwave as a weak solution of Euler equation which is not…
ArtificiallyIntelligence
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4 answers

How to protect users from shock hazards from electric vehicle high voltage system?

I am in the design phase of an electric vehicle. I have realised that at one point, we will need to implement protective measures to safeguard the users from shock hazards of the high voltage system. I understand that we should use an isolated…
gr3en_apple
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1 answer

Is shock spectrum always obtained for an undamped single degree of freedom system?

I am reading a textbook on fundamentals of vibrations and it has a very brief introduction to shock spectra. It mentions that For comparison purposes, it is customary to use the response of an undamped single degree of freedom system to obtain…
ModCon
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Half Sine Impulse in a modal Transient Analysis

I have a MDOF FEM model in which I perform a modal transient analysis based on the modal eigenfrequencies extracted in a prior step. I wish to excite only the first natural frequency of the system via a half sine impulse of 10G. I do not want to see…
shoggananna
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1 answer

Does the surface roughness play any role in shock absorbing?

Consider a mass of about $130 \pm 10 $ kg, falls from height, let say $2.5 $ m. In order to dampen the vibration and sound, I use silencer or drop pads. I was wondering if introducing the macroscopic projections, helps to reduce the thickness of…
Sam Farjamirad
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1
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1 answer

Can hydraulics be used with a squarish piston?

I'm designing a custom part that needs an active shock absorber and space is restricted. I most likely won't be able to use a stock absorber and was thinking, can two squarish tubes be made tight enough?
akauppi
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1
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1 answer

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

I am trying to design a simple drop / shock testing machine. We want to rate our products to be shock rated to 5000g. In order to test our products to 5000g I plan on dropping a weight onto the product imparting a shock. (See drawing) My question…
Luke Thomas
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