Section A –Theoretical questions (15%) 1.What is a ‘three-point-bending’? 2.What information can be retrieved from a ‘three-point-bending’ test? 3.What is a hollow shaft and what is a solid shaft? 4.State one advantage and one disadvantage for a hollow shaft. 5.State one advantage and one disadvantage for a solid shaft. 6.State two engineering applications related to a hollow shaft. 7.State two engineering applications related to a solid shaft. 8.What shape of cross section would you choose for the shaft and why (fully justify your answer)? 9.What materials can be used for a shaft? Describe two examples for each material and include a reference with a picture. 10.What is ‘Finite Element Analysis (FEA) of a structure’? 11.In FEA, what is ‘pre-processing’ of a model? 12.In FEA, what is ‘post-processing’ of a model? 13.In FEA, what is a ‘Degree of Freedom’? 14.In FEA, what is a ‘Reaction Force’? 15.What should a ‘Reaction Force’ be equal to? 16.In FEA, what is a beam element? 17.What is the difference between a beam element and a truss (bar) element? 18.How many degrees of freedom does a 2D beam element have and which are these? 19.Describe all the possible supports that can be applied to the end of a 2D beam. Create a sketch and describe the corresponding support in terms of constrained degrees of freedom. 20.What is the stiffness matrix of a beam element in 2D? 21.What is the physical interpretation of each one of the entries in the stiffness matrix of a beam element in 2D? 22.What is the effect on the beam stiffness if the length of the beam is increased? 23.What is the effect on the beam stiffness if the cross sectional area of the beam is increased? 24.What is the effect on the beam stiffness if the second moment of area of the beam cross section is increased? 25.What is the effect on the beam stiffness if the modulus of elasticity is increased? 26.What is the effect on the beam stiffness if the Poisson’s ratio is increased? 27.What is the effect on the beam stiffness if the thickness of a hollow shaft with given and constant outer dimensions is increased? 28.What is the effect on the beam stiffness if a material with higher thermal coefficient is used? 29.What is the effect on the beam stiffness if a material with higher yield strength is used? 30.What is the effect on the beam stiffness if a material with higher ultimate tensile strength is used?