Answer:
0.024 m = 24.07 mm
Explanation:
1) Notation
= tensile stress = 200 Mpa
= plane strain fracture toughness= 55 Mpa
= length of a surface crack (Variable of interest)
2) Definition and Formulas
The Tensile strength is the ability of a material to withstand a pulling force. It is customarily measured in units (F/A), like the pressure. Is an important concept in engineering, especially in the fields of materials and structural engineering.
By definition we have the following formula for the tensile stress:
(1)
We are interested on the minimum length of a surface that will lead to a fracture, so we need to solve for 
Multiplying both sides of equation (1) by 
(2)
Sequaring both sides of equation (2):
(3)
Dividing both sides by
we got:
(4)
Replacing the values into equation (4) we got:
![\lambda=\frac{1}{\pi}[\frac{55 Mpa\sqrt{m}}{1.0(200Mpa)}]^2 =0.02407m](https://tex.z-dn.net/?f=%5Clambda%3D%5Cfrac%7B1%7D%7B%5Cpi%7D%5B%5Cfrac%7B55%20Mpa%5Csqrt%7Bm%7D%7D%7B1.0%28200Mpa%29%7D%5D%5E2%20%3D0.02407m)
3) Final solution
So the minimum length of a surface crack that will lead to fracture, would be 24.07 mm or more.
Answer:
the maximum bending stress in the strap is 3.02 ksi
Explanation:
Given the data in the question;
steel strap thickness = 0.125 in
width = 2 in
circular arc radius = 600 in
we know that, standard value of modulus of elasticity of L2 steel is; E = 29 × 10³ ksi;
Now, using simple theory of bending
1/p = M/EI
solve for M
Mp = EI
M = EI / p ----- let this be equation 1
The maximum bending stress in the strap is;
σ = Mc / I -------let this be equation 2
substitute equation 1 into 2
σ = ( EI / p)c / I
σ = ( c/p )E
so we substitute in our values
σ = ( (0.125/2) / 600 )29 × 10³
σ = 0.00010416666 × 29 × 10³
σ = 3.02 ksi
Therefore, the maximum bending stress in the strap is 3.02 ksi
C. Route and roadways defined as class I highways
The answer would be 23 because the engines in a horse is a amount of 9 engines in 69 cars