Material properties -- Elastic and Plastic deformation in automobile crashes

In summary: There are undeformed parts which have come to a stop. The deformed parts deform elastically “first.” Parts of the car body have undergone plastic deformation which is detectable by permanent deformation.b) I would say absorbed or dissipated the energy not storedc) the struts are stronger and exhibit less plastic deformation because they are designed to prevent the vehicle from crossing lanes. They transfer energy to the ground. the car body is softer because it is designed to prevent energy from being absorbed by the passenger department, by dissipating the energy via permanent deformationIn summary, the plastic deformation because of
  • #1
shk
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8
Homework Statement
The question has been attached and my answer can be seen below.
Would you please check my answer?
Relevant Equations
Elastic and plastic deformation
a)plastic deformation because of permanent deformation
b) the other parts that have been destroyed have stored the energy and this saved the passenger compartment.
C) the alloy crash barrier is stronger than the car body and and saves more of the energy by deforming shape.

I'm not sure about my answers especially about the answer to part c.

I appreciate your help.
 

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  • #2
Your answers seem to be correct.
Note that C) is asking about the struts supporting the central barrier.
I would replace the reference to strength with one about the different rates of elastic and plastic deformations, which seem to be the goal of the exercise.
 
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  • #3
Lnewqban said:
Your answers seem to be correct.
Note that C) is asking about the struts supporting the central barrier.
I would replace the reference to strength with one about the different rates of elastic and plastic deformations, which seem to be the goal of the exercise.
Thanks for the reply. So do you think if I say the barrier is stronger than the body car , is enough for part c ?
 
  • #4
these are really open ended questions ...
a) the entire car body has undergone elastic deformation. There are undeformed parts which have come to a stop. The deformed parts deform elastically “first.” Parts of the car body have undergone plastic deformation which is detectable by permanent deformation.
b) I would say absorbed or dissipated the energy not stored
c) the struts are stronger and exhibit less plastic deformation because they are designed to prevent the vehicle from crossing lanes. They transfer energy to the ground. the car body is softer because it is designed to prevent energy from being absorbed by the passenger department, by dissipating the energy via permanent deformation
 
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  • #5
caz said:
these are really open ended questions ...
a) the entire car body has undergone elastic deformation. There are undeformed parts which have come to a stop. The deformed parts deform elastically “first.” Parts of the car body have undergone plastic deformation which is detectable by permanent deformation.
b) I would say absorbed or dissipated the energy not stored
c) the struts are stronger and exhibit less plastic deformation because they are designed to prevent the vehicle from crossing lanes. They transfer energy to the ground. the car body is softer because it is designed to prevent energy from being absorbed by the passenger department, by dissipating the energy via permanent deformation
Wow, your explanation really helped.
Thank you very much . I now completely understand this.
Thank you
 
  • #6
caz said:
these are really open ended questions ...
a) the entire car body has undergone elastic deformation. There are undeformed parts which have come to a stop. The deformed parts deform elastically “first.” Parts of the car body have undergone plastic deformation which is detectable by permanent deformation.
b) I would say absorbed or dissipated the energy not stored
c) the struts are stronger and exhibit less plastic deformation because they are designed to prevent the vehicle from crossing lanes. They transfer energy to the ground. the car body is softer because it is designed to prevent energy from being absorbed by the passenger department, by dissipating the energy via permanent deformation
Just one quibble.. the barrier struts are stiffer (not just stronger) yet still, preferably, inelastic to avoid bouncing the car into other lanes.
 
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  • #7
thank you very much . Yes you are right, I should use the word stiffer and inelastic for the struts. your message was very helpful . thank you
 

Related to Material properties -- Elastic and Plastic deformation in automobile crashes

1. What is the difference between elastic and plastic deformation in automobile crashes?

Elastic deformation refers to the temporary change in shape of a material when a force is applied, which can be reversed once the force is removed. Plastic deformation, on the other hand, refers to a permanent change in shape of a material when a force is applied, which cannot be reversed.

2. How do material properties affect the outcome of an automobile crash?

Material properties such as strength, ductility, and toughness play a crucial role in determining the outcome of an automobile crash. A material with high strength and ductility can absorb more energy during a collision, while a material with low toughness may shatter or break easily, leading to more severe damage.

3. Can a material exhibit both elastic and plastic deformation during an automobile crash?

Yes, a material can exhibit both elastic and plastic deformation during an automobile crash. This is because the initial impact may cause elastic deformation, but as the force increases, the material may undergo plastic deformation.

4. What factors influence the extent of elastic and plastic deformation in an automobile crash?

The extent of elastic and plastic deformation in an automobile crash is influenced by factors such as the speed and angle of impact, the type and strength of materials involved, and the design of the vehicle's structure.

5. How do scientists study the elastic and plastic deformation in automobile crashes?

Scientists use various methods such as computer simulations, crash tests, and material testing to study the elastic and plastic deformation in automobile crashes. These methods help them understand the behavior of different materials and how they respond to different forces during a collision.

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