Problem 4

Choose from the Section Table below the most weight efficient pin-ended 5 m long column that can carry a load of 55 kN without failing by buckling or yielding. [2 marks]

Note in the Table, Grade 250L0 represents a material yield stress of 250 MPa.

Take E_steel = 200,000MPa

Problem 4

A 4.5 m long pin ended column supports a maximum axial compression load of 40 kN without failing by buckling or yielding.  The column is required to support a greater load and this is achieved by changing the one end of the column to be fixed rigidly to its concrete foundation.  What is the axial load the column can now carry without failing? [1 mark]

Provide you answer to 2 decimal places in units of kN. 

b) Assuming the member will fail by buckling, calculate the maximum axial load the member can carry in kN. [2 marks]

Provide your answer to two decimal places as a positive value.

Problem 3

The figure below shows the rectangular cross-section, of dimensions b=124 mm and t=13 mm, of a steel member of length 4m. The member has pin end supports and experiences axial compressive loading. 

Assume Young’s modulus E = 200,000 MPa and a yield strength σ_y =250 MPa.

a) What is the 'squash load' of this member? [1 mark]   

Provide your answer tin units of kN two decimal places as a  positive value.

g) With different loading applied a free body diagram at joint C looks like the following;

 The 20 kN and 15 kN forces represent the reaction forces at the support at C.  A method of Joints at other joints reveals forces F_BC = -10 kN (compression)  and  F_CF= 7.5 kN (tension). 

Calculate the value of the force F_CH  in  kN?  [2 marks]

Assume the same angles between all members as previously.

Problem 1

A pin jointed truss structure is shown in Figure 1.

Three point loads are applied to the system as shown.  The truss is supported by a vertical roller support at D and a pin support at C.

Note: Incorrect answers chosen here will incur penalty marks.

Figure 1

a) By inspection (without calculation) note which members in the truss have zero force in them?  

g) With different loading applied a free body diagram at joint C looks like the following;

 The 20 kN and 15 kN forces represent the reaction forces at the support at C.  A method of Joints at other joints reveals forces F_BC = -10 kN (compression)  and  F_CF= 8.5 kN (tension). 

Calculate the value of the force F_CH  in  kN?  [2 marks]

Assume the same angles between all members as previously.

Problem 1

A pin jointed truss structure is shown in Figure 1.

Three point loads are applied to the system as shown.  The truss is supported by a vertical roller support at D and a pin support at C.

Note: Incorrect answers chosen here will incur penalty marks.

Figure 1

a) By inspection (without calculation) note which members in the truss have zero force in them?