Free fall and impact force calculation

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SUMMARY

The discussion focuses on calculating the impact force on screws when a 27-pound box is dropped from a height of 5 feet onto a concrete surface. The user attempts to apply the basic impact force formula and conservation of energy principles but struggles due to the lack of information regarding the distance after impact (D). It is established that the impact force is influenced by the duration of the impact, which varies with the surface material. The user seeks to compare the effects of using 16 versus 24 screws in securing the box.

PREREQUISITES
  • Understanding of basic physics principles, specifically impact force calculations.
  • Familiarity with conservation of energy concepts.
  • Knowledge of material properties, including shear modulus and impact resistance.
  • Experience with mechanical fastening systems, particularly screw load distribution.
NEXT STEPS
  • Research the formula for calculating impact force, including variables such as time of impact and material properties.
  • Learn about the effects of different surface materials on impact force absorption.
  • Investigate the relationship between screw count and load distribution in mechanical assemblies.
  • Explore the concept of shear modulus and its application in evaluating screw performance under load.
USEFUL FOR

Mechanical engineers, materials scientists, and anyone involved in structural design or impact analysis of mechanical assemblies will benefit from this discussion.

bama ing
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first of all I have a case that is screwed in another case ,I like to know a basic way to calculate the impact force in the screws ,the are 16 screws, I try using the basic impact force formula and the conservation of energy in the free fall,but I am having problems since I don't have the D which apparently its the distance after the impact.The weigh of the box is 27 lbs and its throwed from 5 ft.
 
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It's impossible to know what the impact force is going to be without knowing some properties of the falling object and the surface they are hitting.

The force will depend on the amount of time the impact takes. With softer surface, impact will take longer, and forces will be lower.
 
thnax,can i incorporate that information to the formula,I mean if I findt hat kind of info
 
Impact force

I have a 27 pound box attached to a another box by 16 screws in 4 brackets one for every corner,I like to compare the effect of the impact if I put 16 screws or if I put 24(like the number of holes in the bracket).It would be dropped from 5 ft to a concrete slab,the material of the outside box its a TSC composite material.So I think what I need its the impact force that will received the box and that will tranfer to the screws,after that I can divided by the section area of the screws and compare that to the shear modulus,but I am not sure.
 

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