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Engineering Stack Exchange

Questions tagged [impact]

16 questions
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Is a single large impact better than several small impacts for breaking ice

I'm designing a device that uses impact to remove ice from sidewalks. I have a question about how to best design the impact mechanism. I can design it to deliver several light impacts or fewer harder impacts. The energy will be the same in both…
henradrie
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Testing specimens by dropping a ball on them and counting the number of drops required before the collapse. A better way?

A huge number of specimens are built. For each specimen, soil is mixed with cement (and Zeolite) with different percentages. It's intended to test, measure and compare the impact strength of the specimens. One test option One test approach is to…
user3405291
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How do you estimate the energy of an impact?

I am trying to determine the energy of elastic stress waves generated in a solid by an impact. I have a time domain waveform from a piezoelectric transducer that was placed next to the impact site, as well as the voltage/displacement calibration of…
Vishnu Venkatesh
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Vibration following an impact

This high-speed video shows a cymbal's response to impact. I'm interested in how the observed vibration relates to the modes and frequencies that an eigenvalue vibration analysis would predict. My interest is not specific to cymbals, the video just…
ik2
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How does an impact driver convert the lateral motion of the spring expansion, into rotational force?

It seems to be that the consensus behind impact drivers is that when the tool stalls, the hammer camms off the anvil, picks up speed turning 180 degrees, and then the moving hammers strike the anvil, losing all their energy, and using inertia of the…
sergbot
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Can someone please explain how impact is absorbed?

I am unable to understand how springs and shock absorbers absorb impact. So it would be great if someone could explain how impact is absorbed; and if it could be used to protect someone's leg from beaking when falling from a height. Thanks in…
Sreenandan Balasubramaniam
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Bending stress wave resulting from a lateral impact on a beam

I want to approximate a bending stress wave resulting from a lateral impact on a beam which is on one end fixed. According to Roarks 16.3-3 I can estimate a compressive stress wave from one mass impacting on a bar with one end fixed: $E$ is…
meshWorker
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Does hitting an obstacle hard enough to break it actually reduce self harm?

Lets say that Car-A hits barrier that is fixed to immovable posts on either side of the road. The car's momentum is such that the barrier absorbs the impact and the car comes to a near instantaneous halt and incurs some degree of smash damage. An…
Lorry Laurence mcLarry
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How effective are screen protectors?

Screen protectors are supposed to protect your devices from nicks and scratches, as well as the stress of impacts which might otherwise lead to cracks or shattering. The fundamental principle behind their operation is that screen-protector glass or…
10GeV
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How to create a mechanical equivalent to dropping object onto steel floor

(I was informed on the Physics board that this is an Engineering question, therefore they closed it there, and I moved it here) First, I have next to zero formal physics training... I opted for all math & electronics electives back in my 1970s high…
RTC
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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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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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Replicating an impact impulse

I am building a test-rig for a device. I have operational data showing the device experiences impact loads resembling a half-sine pulse with width dt and magnitude F. The test rig's purpose is to replicate this force to gather life cycle data. The…
engstudent296
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Can the fragility of ceramic armor be avoided by creating ceramic material with little to no defects?

Sorry if the question is wrong/confusing but this is because the subject is confusing, especially when you don't have a degree in engineering/materials science. Ceramic armor usually breaks upon impact by a projectile/HEAT charge so my question is,…
bombadil
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How to calculate beam impact problem

Can anyone help with this Impact problem? It does not seem very difficult but I am having trouble putting all the parts together. Thanks,
Justin E
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