Question

# Q1 A mass of mi, supported at the structure shown in Fig Q1 can be modeled as a single degree of freedom system of mass (m), spring stiffness (k), damper

(c), in vertical direction. The flexural rigidity of both beam AB and CD are El; Nm?, The shear stiffness of the two beams AB and CD are both 12EI/L, The column between the two beam AB and CD can be consider as rigid. Please work out the natural frequency of the structure. (30 Marks) Use the following numerical values: Mass mi • add all digits from your date of birth and divide by 4 to obtain A in metric tons,i.e. for 19/04/82 you would get A= (1+9+0+4+8+2)/4=6tn= 6000kg Flexural rigidity Elj write down your name and surname (e.g. Jane Student) replace all letters that are alphabetically before K with 1 and all others with 0 i.e. for Jane Student one would get 1,1,0,1,0,0,0,1,1,0,0 • add all numbers obtained in this way and multiply by 1x107 to get B in Nm2,i.e. B=(1+1+0+1+0+0+0+1+1+0+0)*1x107= 5x107 Nm2

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