Answer:
- hoop stress
- longitudinal stress
- material used
all this could led to the failure of the garden hose and the tear along the length
Explanation:
For the flow of water to occur in any equipment, water has to flow from a high pressure to a low pressure. considering the pipe, water is flowing at a constant pressure of 30 psi inside the pipe which is assumed to be higher than the allowable operating pressure of the pipe. but the greatest change in pressure will occur at the end of the hose because at that point the water is trying to leave the hose into the atmosphere, therefore the great change in pressure along the length of the hose closest to the end of the hose will cause a tear there. also the other factors that might lead to the failure of the garden hose includes :
hoop stress ( which acts along the circumference of the pipe):
αh =
EQUATION 1
and Longitudinal stress ( acting along the length of the pipe )
αl =
EQUATION 2
where p = water pressure inside the hose
d = diameter of hose, T = thickness of hose
we can as well attribute the failure of the hose to the material used in making the hose .
assume for a thin cylindrical pipe material used to be
≥ 20
insert this value into equation 1
αh =
= 60/2 = 30 psi
the allowable hoop stress was developed by the material which could have also led to the failure of the garden hose
Answer:
The value of critical length = 3.46 mm
The value of volume of fraction of fibers = 0.43
Explanation:
Given data
= 800 M pa
D = 0.017 mm
L = 2.3 mm
= 5500 M pa
= 18 M pa
= 13.5 M pa
(a) Critical fiber length is given by
![L_{c} = \sigma_{f} (\frac{D}{2 \sigma_{c} } )](https://tex.z-dn.net/?f=L_%7Bc%7D%20%3D%20%5Csigma_%7Bf%7D%20%28%5Cfrac%7BD%7D%7B2%20%5Csigma_%7Bc%7D%20%7D%20%29)
Put all the values in above equation we get
![L_{c} =5500 (\frac{0.017}{(2) (13.5)} )](https://tex.z-dn.net/?f=L_%7Bc%7D%20%3D5500%20%28%5Cfrac%7B0.017%7D%7B%282%29%20%2813.5%29%7D%20%29)
mm
This is the value of critical length.
(b).Since this critical length is greater than fiber length Than the volume fraction of fibers is given by
![V_{f} = \frac{\sigma_T - \sigma_m}{\frac{L\sigma_c}{D} - \sigma_m }](https://tex.z-dn.net/?f=V_%7Bf%7D%20%3D%20%5Cfrac%7B%5Csigma_T%20-%20%5Csigma_m%7D%7B%5Cfrac%7BL%5Csigma_c%7D%7BD%7D%20-%20%5Csigma_m%20%7D)
Put all the values in above formula we get
![V_{f} = \frac{800-18}{\frac{(2.3)(13.5)}{0.017} - 18 }](https://tex.z-dn.net/?f=V_%7Bf%7D%20%3D%20%5Cfrac%7B800-18%7D%7B%5Cfrac%7B%282.3%29%2813.5%29%7D%7B0.017%7D%20-%2018%20%7D)
= 0.43
This is the value of volume of fraction of fibers.
Answer:
(a) Surface energy is greater than grain boundary energy due to the fact that the bonds of the atoms on the surface are lower than those of the atoms at the grain boundary. The energy is also directly proportional to the number of bonds created.
(b) The energy of a high-angle grain boundary is higher than that of a small-angle grain boundary because the high-angle grain boundary has a higher misalignment and smaller number of bonds than a small-angle grain boundary.
Explanation:
(a) Surface energy is greater than grain boundary energy due to the fact that the bonds of the atoms on the surface are lower than those of the atoms at the grain boundary. The energy is also directly proportional to the number of bonds created.
(b) The energy of a high-angle grain boundary is higher than that of a small-angle grain boundary because the high-angle grain boundary has a higher misalignment and smaller number of bonds than a small-angle grain boundary.