Name: pipe wall thickness and bending strength
Uploaded: 2024-05-23T12:59:43.000Z
Duration: 1 min 9 s
Channel: JoVE

Consider two metallic pipes having an inner radii of 1.5 cm and 1 cm, respectively, and an outer radii of 1.8 cm. If both pipes can withstand a maximum stress of 100 megapascals, then what will be the ratio of the maximum value of the couple that can be applied to each pipe?
Here, the moment of inertia of the pipe is proportional to the difference between the outer radius raised to the fourth power and the inner radius raised to the fourth power. The moment of inertia for each pipe is calculated by substituting the given radii.
The required maximum allowed couple moment is related to the maximum allowed stress via the moment of inertia and the perpendicular distance between the outmost element of the pipe to the neutral axis, which is the outer radii for each pipe.
Substituting the known values, the maximum allowed couple for each pipe can be calculated.
Dividing the maximum couple moments for each pipe gives the required ratio.

bending of material: problem solving

In this lesson, determine the ratio of the maximum bending moments applied to two metal pipes, given that both pipes can withstand a maximum stress of 100 MPa. Both pipes have an outer radius of 1.8 cm. Pipe A has an inner radius of 1.5 cm, and Pipe B has an inner radius of 1 cm. The ratio of the maximum bending moment applied to two metallic pipes, each with a different inner and outer radius, is determined by considering their dimensions. The inner radius of the first pipe is 1.5 cm, and for the second pipe, it is 1 cm.
The moment of inertia is given by the following equation. Using these values, calculate the moment of inertia for each pipe.
<img alt="Static equilibrium, formula \( I_A = \frac{\pi(R_o^4 - R_i^4)_A}{4} \), mechanical analysis." src="/files/ftp_upload/15629/15629_Equation_1a.svg" style="text-align: center; height: 36px;" data-altupdatedat="1762173717000" data-alt="Equation 1" />
<img alt="Static equilibrium formula, IB=(&#960;(Ro^4-Ri^4)B)/4, structural analysis equation." src="/files/ftp_upload/15629/15629_Equation_1b.svg" style="text-align: center; height: 36px;" data-altupdatedat="1762173717000" data-alt="Equation 2" />
The maximum allowable bending moment for each pipe directly relates to the maximum stress, the moment of inertia, and the outer radius, which serves as the distance from the neutral axis to the extreme outer fiber of the pipe, as shown in the following equation:
<img alt="Magnetic field equation \(M_A=\frac{\sigma_m I_A}{R_{oA}}\) in electromagnetism context." src="/files/ftp_upload/15629/15629_Equation_2a.svg" style="text-align: center; height: 42px;" data-altupdatedat="1762173717000" data-alt="Equation 3" />
<img alt="Magnetic balance equation, \( M_B = \frac{\sigma_m I_B}{R_{0B}} \), used in static equilibrium analysis." src="/files/ftp_upload/15629/15629_Equation_2b.svg" style="text-align: center; height: 42px;" data-altupdatedat="1762173717000" data-alt="Equation 4" />
Then, the maximum bending moment for each pipe will be determined using these calculated values. Finally, the ratio of these maximum bending moments for the two pipes is calculated. This ratio indicates each pipe's comparative torsional strength and resilience under maximum permissible stress. It also highlights the effect of the pipe's wall thickness on the maximum bending moment in this situation.

Bending of Material: Problem Solving

Consider two metallic pipes having an inner radii of 1.5 cm and 1 cm, respectively, and an outer radii of 1.8 cm. If both pipes can withstand a maximum ...

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Mechanical Engineering

Unit 1

Bending

KEY TERMS AND CONCEPTS

pipe wall thickness and bending strength

Pipe wall thickness and bending strength are compared by finding the ratio of the maximum bending moments for two metal pipes. Both pipes can withstand a maximum stress of 100 MPa. Each pipe has the same outer radius of 1.8 cm, but Pipe A has an inner radius of 1.5 cm and Pipe B has an inner radius of 1 cm.

The first step is to calculate the moment of inertia for each pipe. The moment of inertia depends on the pipe dimensions and is found using the given equation for a hollow circular section. Because the two pipes have different inner radii, they will have different moment of inertia values even though their outer radii are the same.

Next, the maximum allowable bending moment is determined from the maximum stress, the moment of inertia, and the outer radius. The outer radius gives the distance from the neutral axis to the extreme outer fiber of the pipe. Using the calculated values, the maximum bending moment for each pipe is found.

Finally, the ratio of the two maximum bending moments is calculated. This ratio shows how the pipes compare in bending strength under the same stress limit. It also shows how wall thickness affects the maximum bending moment, since the pipe with the different inner radius responds differently under maximum permissible stress.

Pipe Wall Thickness and Bending Strength

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Pipe wall thickness and bending strength are compared by finding the ratio of the maximum bending moments for two metal pipes. Both pipes can withstand a maximum stress of 100 MPa. Each pipe has the same outer radius of 1.8 cm, but Pipe A has an inner radius of 1.5 cm and Pipe B has an inner radius of 1 cm. The first step is to calculate the moment of inertia for each pipe. The moment of inertia depends on the pipe dimensions and is found using the given equation for a hollow circular section.

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key terms and concepts

Compare two metal pipes with different inner radii and find the ratio of their maximum bending moments using stress, moment of inertia, and outer radius.

Pipe Wall Thickness and Bending Strength | JoVE K12

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Pipe Wall Thickness and Bending Strength

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