No problem, glad I could help!

In summary, the conversation discusses a design calculation for determining the suitable size of a hinge pin for a beam subjected to loading. The shear strength of the pin material and the factor of safety are given, and the participants discuss the calculation of reaction forces, the maximum working shear stress in the pin, and a suitable diameter for the pin. The participants come to a consensus on the answers and one of them expresses gratitude for the help and clarification provided by the other.
  • #1
BIGEYE
20
0
Appreciate if someone can check my answers to the following question:

A beam hinged at one end and simply supported at the other is subjected to the loading shown. A design calculation is required to determine the suitable size of hinge pin. If wrong, could you point me in the right direction.

Data Shear strength of pin material = 20 MN/m^2
Factor of safety = 5

Drawing of system can be found here:

http://img206.imageshack.us/img206/6549/oc2q3gc5.jpg a) Use these conditions to determine the reaction forces RP and R1b) State the maximum working shear stress in the pin.c) Calculate a suitable diameter for the pin to the nearest millimeter.a) My answers are RP = 1700 N, and R1 = 800 N.

b) My answer 4 MN/m^2

c) My answer = 16 mm
 
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  • #2
BIGEYE said:
Appreciate if someone can check my answers to the following question:

A beam hinged at one end and simply supported at the other is subjected to the loading shown. A design calculation is required to determine the suitable size of hinge pin. If wrong, could you point me in the right direction.

Data Shear strength of pin material = 20 MN/m^2
Factor of safety = 5

Drawing of system can be found here:

http://img206.imageshack.us/img206/6549/oc2q3gc5.jpg


a) Use these conditions to determine the reaction forces RP and R1


b) State the maximum working shear stress in the pin.


c) Calculate a suitable diameter for the pin to the nearest millimeter.


a) My answers are RP = 1700 N, and R1 = 800 N.

b) My answer 4 MN/m^2

c) My answer = 16 mm
Your answers look correct to me. The pin is in a classic case of double shear.
 
Last edited by a moderator:
  • #3
Thanks for taking the time.
 
  • #4
Determine Pin Size?

PhanthomJay said:
Your answers look correct to me. The pin is in a classic case of double shear.

hey guys .. I am just wondering how you went about calculating the maximum shearing stress in the pin, and from that determining pin size ...

your help would be of most value ..
Thanks in advance
 
  • #5
komy said:
hey guys .. I am just wondering how you went about calculating the maximum shearing stress in the pin, and from that determining pin size ...

your help would be of most value ..
Thanks in advance
The allowable shear stress in the pin with a 5.0 safety factor is "given" as 20/5 = 4MN/m^2. However, the pin is in double shear, so effectively the allowable shear stress can be taken as twice that value (8MN/m^2). The 1700N pin force was calculated from statics. Pin shear stress is shear force divided by cross sectional area of pin (1700N/A = 8MN/m^2). Solve for A, then diameter; watch units and decimal point.

Please ask again if you don't understand the concept of double shear.
 
  • #6
PhanthomJay said:
The allowable shear stress in the pin with a 5.0 safety factor is "given" as 20/5 = 4MN/m^2. However, the pin is in double shear, so effectively the allowable shear stress can be taken as twice that value (8MN/m^2). The 1700N pin force was calculated from statics. Pin shear stress is shear force divided by cross sectional area of pin (1700N/A = 8MN/m^2). Solve for A, then diameter; watch units and decimal point.

Please ask again if you don't understand the concept of double shear.


mate i totally understand it now ..
thanks for your help !
 

1. What is the importance of selecting the correct pin size for a design?

The correct pin size is crucial because it ensures that the design can withstand the intended load and function properly. Using a pin that is too small may result in failure and using a pin that is too large may add unnecessary weight and cost to the design.

2. How do you determine the suitable pin size for a specific application?

The suitable pin size can be determined by considering factors such as the expected load, material strength, and the pin's intended function within the design. Calculations and simulations can also be used to determine the appropriate pin size.

3. What are the common types of pins used in design and their corresponding size ranges?

Common types of pins include dowel pins, taper pins, and spring pins. The size range for these pins varies depending on the specific type and application, but generally ranges from 1/16 inch to 1 inch in diameter.

4. How does material selection affect the suitable pin size?

The material of the pin should be selected based on its strength and compatibility with the materials it will be interacting with in the design. Stronger materials may allow for smaller pin sizes, while weaker materials may require larger pin sizes to support the load.

5. Are there any industry standards for selecting suitable pin sizes?

Yes, there are industry standards such as ASME B18.8.2 and ISO 2338 that provide guidelines for selecting suitable pin sizes based on load and material properties. These standards should be consulted when designing with pins to ensure optimal performance and safety.

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