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ENGINEERING, CS 2024 HSC 16 MC

An -beam is loaded as shown.
 

The load is then increased.

Which increase in dimension would provide the most resistance to bending?

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→ The most efficient way to increase bending resistance in an -beam would be to increase the height/depth of the web , since resistance to bending increases with the cube of the depth from neutral axis.

♦ Mean mark 46%.

ENGINEERING, CS 2023 HSC 22b

The diagram shows a child with a mass of 45 kg hanging 2 metres from the left end of a structure, and an adult with a mass of 85 kg hanging 1 metre from the right end.

 

  1. Calculate the reactions at and .   (3 marks)
      

 

  1. Complete the shear force and bending moment diagrams of the scenario described.   (3 marks)

 

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i.   

  
ii.    

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i.   

 
 
 

 

 
 

 
ii.    

ENGINEERING, CS 2019 HSC 21d

A pictorial sketch of a laminated timber beam used in a bus shelter is shown. This beam has a second moment area of . The maximum applied bending moment is 17 kNm.
 

  1. Calculate the maximum bending stress present in the beam.   (3 marks)
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Second Moment of Area ()

Maximum Bending Moment ()

Distance (Neutral axis → outside of beam) = 125 mm

 
   
   

ENGINEERING, CS 2018 HSC 23c

The chassis for a motor vehicle could be made from a solid steel bar or hollow steel tube. Both the bar and the tube have the same mass and cost per metre.
 

Justify why a hollow tube would be used in preference to a solid bar to build the vehicle chassis.   (3 marks)

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→ Hollow tube has a higher second moment of area and is therefore more rigid.

→ Because the chassis is exposed to continual flexural forces and moments when the vehicle is moving, rigidity is important.

→ Stiffness is therefore a major design requirement.

→ The hollow tube also provides damage protection for any electrics cabling.

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→ Hollow tube has a higher second moment of area and is therefore more rigid.

→ Because the chassis is exposed to continual flexural forces and moments when the vehicle is moving, rigidity is important.

→ Stiffness is therefore a major design requirement.

→ The hollow tube also provides damage protection for any electrics cabling.

♦♦ Mean mark 35%.

ENGINEERING, CS 2017 HSC 27b

An engineering team has been contracted to design a multi-function lifting device for a coastal container wharf.

The table shows some of the engineering design elements for this lifting device.
 

Explain how the lifting device can be tested and evaluated to determine if the criteria for the listed engineering elements are met.   (6 marks)

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♦ Mean mark 46%.

ENGINEERING, CS 2019 HSC 23d

A scooter deck, made from aluminium alloy, and its cross-section are shown.

The scooter's manufacturer is concerned that there is too much deflection along the length of the deck when a rider stands on it.

Describe ONE suitable design modification to give the deck greater rigidity without adding extra mass. Use a labelled sketch to support your answer.   (3 marks)

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Design modifications

→ Add longitudinal ribbing to the deck, ensuring not to create additional mass.

→ This will create an increase in the distance of the neutral axis from the bottom of the deck and a thinner wall structure.

→ The outcome will be a decrease in deflection

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Design modifications

→ Add longitudinal ribbing to the deck, ensuring not to create additional mass.

→ This will create an increase in the distance of the neutral axis from the bottom of the deck and a thinner wall structure.

→ The outcome will be a decrease in deflection


 
♦ Mean mark 41%.