Correct Answer - Option 4 : (a) - 4, (b) - 3, (c) - 1, (d) – 2
Explanation:
Kinematical mechanism method of ultimate load analysis:
It states that collapse is formed by assuming a mechanism will always be greater than or equal to true collapse load. i.e. P ≥ Pu.
It satisfies the equilibrium and mechanism conditions.
It is called the Upper bound theorem as it gives upper limit of the true collapse load.
Static method of ultimate load analysis:
It states that collapse load found on the basis of any collapse bending moment diagram will be less than or equal to true collapse load. i.e. P ≤ Pu.
It satisfies the Equilibrium and Yield conditions.
It is called Lower bound theorem as it gives lower limit of the true collapse load.
Load factor:
It is the factor used to increase the working load to account for the effect of various uncertainties in working load calculation. It is given as
Design load = Load factor × Working load
Factor of safety:
It is the factor used to reduce the ultimate strength of material so that more safety may be ensured while designing a structure.
Design strength = Ultimate strength/FOS