Table of Contents
- 1 Why does stress decrease after ultimate point?
- 2 Which point on the stress strain curve occurs after the ultimate limit?
- 3 Why breaking load is less than maximum load?
- 4 Why does yield decrease?
- 5 Which point on the stress-strain curve occurs before elastic limit?
- 6 Why is proportional limit important in engineering design?
- 7 What is the yield strength point on the stress-strain graph?
- 8 Why is there a dip in the stress-strain curve?
Why does stress decrease after ultimate point?
The dip in the curve implies that the engineering stress decreases after the UTS. This is because of the development of a local reduction in the cross sectional area of the specimen. A triaxial state of stress is thus resulted at the neck.
Why does the stress strain curve decrease after yield point?
After the yield point, the curve typically decreases slightly because of dislocations escaping from Cottrell atmospheres. As deformation continues, the stress increases on account of strain hardening until it reaches the ultimate tensile stress.
Which point on the stress strain curve occurs after the ultimate limit?
Which point on the stress strain curve occurs after the ultimate point? Explanation: After the ultimate point the value of stress will reduce on increasing of strain and ultimately the material will break. Explanation: The elastic limit is that limit up to which any material behaves like an elastic material. 8.
What would be the correct outcome after a specimen has been loaded and unloaded to its 0.2 percent offset yield strength?
A good way of looking at offset yield strength is that after a specimen has been loaded to its 0.2 percent offset yield strength and then unloaded it will be 0.2 percent longer than before the test.
Why breaking load is less than maximum load?
Again, it is not the load we control but we measure the the load required for the controlled displacement of the ends. So, after the ultimate tensile strength point, this load required for moving the ends apart is less than before hence F/A decreases.
When the stress decreases with time without changing the strain is known as?
5.2. 2.1 Compression Stress Relaxation. The definition of compression stress relaxation is that when a constant strain is applied to the gasket sample, the force necessary to maintain that strain is not constant but decreases with time; this behavior is called stress relaxation.
Why does yield decrease?
A few materials start to yield, or flow plastically, at a fairly well-defined stress (upper yield point) that falls rapidly to a lower steady value (lower yield point) as deformation continues. Any increase in the stress beyond the yield point causes greater permanent deformation and eventually fracture.
What happens lower yield point?
Below the yield point, a material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible and is known as plastic deformation.
Which point on the stress-strain curve occurs before elastic limit?
| Q. | Which point on the stress strain curve occurs after the ultimate point? |
|---|---|
| C. | elastic limit |
| D. | material limit |
| Answer» b. breaking point | |
| Explanation: after the ultimate point the value of stress will reduce on increasing of strain and ultimately the material will break. |
What is the strain energy stored in a body when the load is applied with impact?
1. What is the strain energy stored in a body when the load is applied with impact? Explanation: Strain energy in impact loading = σ2V/2E. Explanation: The value of stress is calculated by equating the strain energy equation and the work done equation.
Why is proportional limit important in engineering design?
The proportional limit is the point on a stress-strain curve where the linear, elastic deformation region transitions into a non-linear, plastic deformation region. In other words, the proportional limit determines the greatest stress that is directly proportional to strain.
Why is 0.2 proof stress used?
Although as mentioned by others this is not universally accepted, in my opinion the reason that the 0.2\% strain was used for proof stress, is that it offers a more straight forward comparison with the yield stress of steel. Steel has a distinct yield point, that you can use to set a good safety margin before failure.
What is the yield strength point on the stress-strain graph?
This aligns with the start of the strain hardening region in the stress-strain graph. The yield strength point is where the plastic deformation of the material is first observed. If the material is unclamped from the testing machine beyond this point, it will not return to its original length.
Why is the stress-strain curve important in Mechanical Engineering?
The stress-strain curve provides design engineers with a long list of important parameters needed for application design. A stress-strain graph gives us many mechanical properties such as strength, toughness, elasticity, yield point, strain energy, resilience, and elongation during load. It also helps in fabrication.
Why is there a dip in the stress-strain curve?
That’s why there is a dip in the curve, which is wrong. This thing is not evident in true stress-strain curve. Stress value is calculated using instantaneous cross-sectional area and hence there is no dip.
What happens to load P as stress increases?
So the load P is going to increase as long as the incremental increase in stress is greater than the incremental decrease in Area. This is what happens between yield and ultimate. The material yields locally. There is local reduction in area.