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3 years ago

What is the definition of a tolerance on a dimension typically found on technical drawings?

1 answer:

7 0

Tolerance is the acceptable amount of dimensional variation that still allows a part to perform as designed.

Any process will have variation and depending on the severity of the function some tolerance will be very small. For example the sheet metal thickness on portion of a space shuttle will have a much tighter tolerance than the thickness of a piece of lumber to build a house. Tighter tolerance of processes typically are related to more process control (e.g. money) thus designs should be fully vetted with process team before placing on a drawing.

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A 304 stainless steel (yield strength 30 ksi) cylinder has an inner diameter of 4 in and a wall thickness of 0.1 in. If it is su

Natasha_Volkova [10]

Answer:

The value we got is 1.423 ksi which is less than 30 and so the material hasn't failed and yielding hasn't occured.

Explanation:

This is a cylindrical thin walled vessel. Thus;

Hoop stress; σ1 = pr/t

Where ;

p is internal pressure

r_o is radius = 4/2 = 2 in

t is thickness of wall = 0.1 in

Thus;

σ1 = 70 x 2/0.1 = 1400 ksi

Longitudinal stress; σ2 = pr/2t

σ2 = 70 x 2/(0.1 x 2) = 700 ksi

Now, we want to find the normal stress. The inner radius of the circle will be; r_i = r_o - t = 2 - 0.1 = 1.9 in

So, normal stress by axial force is given by;

σ_fx = F/A = F/(π(r_o² - r_i²))

We are given that F = 500 lb

σ_fx = 500/(π(2² - 1.9²))

σ_fx = 408.1 ksi

We can now find the torsion from the formula;

τ = (T•r_o)/J

We are given that T = 70 lb.ft = 70 x 12 lb.in = 840 lb.in

J is the polar moment of inertia and has a formula; ((π/2)(r_o⁴ - r_i⁴))

So,J = ((π/2)(2⁴ - 1.9⁴)) = 4.662 in⁴

Thus,τ_xy = (840 x 2)/4.662 = 360.4 ksi

σ1 is in the y direction and σ2 is in the x direction. Thus;

σ_x = σ1 + σ_fx = 700 + 408.1 = 1108.1 ksi

Also, σ_y = σ1 = 1400 ksi

Now distortion energy can be expressed as;

σ_Y² = σ_x - σ_x•σ_y + (σ_y)² + 3(τ_xy)²

Plugging in the relevant values, we obtain ;

σ_Y² = 1108.1² - (1108.1*1400) + 1400² + 3(360.4)²

So, σ_Y² = 2.02 x 10^(6) psi²

σ_Y = √2.02 x 10^(6)

σ_Y = 1423 psi = 1.423 ksi

The question says the yield strength of the material is 30 ksi.

The value we got is less than 30 and so the material hasn't failed and yielding hasn't occured.

8 0

3 years ago

A thin-film gold conductor for an integrated circuit in a satellite application is deposited from a vapor, and the deposited gol

ahrayia [7]

Answer:

Explanation:

Considering the relation of the equilibrium vacancy concentration ;

nv/N = exp (-ΔHv/KT)

Where T is the temperature at which the vacancy sites are formed

K = Boltzmaan constant

ΔHv = enthalpy of vacancy formation

Rearranging the equation and expressing in term of the temperature and plugging the values given to get the temperature. The detailed steps is as shown in the attached file

5 0

3 years ago

Technician A says that a special wire brush is needed if it will be rotated at high rpm. Technician B says that some wire brushe

Charra [1.4K]

Answer:

Option C

Both A and B

Explanation:

Both technicians are right about what they say about wire brushes. wire brushes are usually made up of steel wire bristles. however, when high RPMs are involved, it is better to get some special types of brushes for that purpose. This is because the heat generated at high RPMs is great, and most times, damages the brush after prolonged use if it is not specially built for such speeds.

In addition that, some wire brushes have plastic hubs which help support the bristles and is usually attached to the motor.

Considering these, we can say that the Two technicians are right

5 0

4 years ago

The repair and rehabilitation of damaged or spalled concrete is done by removing the:____________A. Loose concreteB. CollapsingC

Mrac [35]

Answer:

A. Loose concrete

Explanation:

Concrete is a solid composite structural material.It is the most used component in setting up a structure. Concrete is known for its very good ability to bear load, but can sometimes fail, or can be damaged. To rehabilitate or repair a concrete, the loose concrete must first be removed, so that the surface can be cleaned and well set before the material used for repair is applied on it.

8 0

3 years ago

an amplifier has an input resistance of 100k a short-circuit transconductance of 10 mA/V and an output resistance of 100k. Find

Vlada [557]

Answer:

The open circuit voltage gain is $A_{vo}=-10^{3}$