List of top Structural Engineering Questions

A single story building model is shown in the figure. The rigid bar of mass \( m \) is supported by three massless elastic columns whose ends are fixed against rotation. For each of the columns, the applied lateral force (P) and corresponding moment (M) are also shown in the figure. The lateral deflection (\( \delta \)) of the bar is given by \( \delta = \dfrac{PL^3}{12EI} \) where \( L \) is the effective length of the column, \( E \) is the Young's modulus of elasticity and \( I \) is the area moment of inertia of the column cross-section with respect to its neutral axis. 
For the lateral deflection profile of the columns as shown in the figure, the natural frequency of the system for horizontal oscillation is 

Strain hardening of structural steel means

A rectangular cross-section of a reinforced concrete beam is shown in the figure. The diameter of each reinforcing bar is 16 mm. The values of modulus of elasticity of concrete and steel are \( 2.0 \times 10^4 \, \text{MPa} \) and \( 2.1 \times 10^5 \, \text{MPa} \), respectively. 

The distance of the centroidal axis from the centerline of the reinforcement (in mm, round off to one decimal place) is \(\underline{\hspace{1cm}}\).

The activity details for a small project are given in the Table. 

\[ \begin{array}{|c|c|c|} \hline \text{Activity} & \text{Duration (days)} & \text{Depends on} \\ \hline A & 6 & - \\ B & 10 & A  \\ C & 14 & A \\ D & 8 & B \\ E & 12 & C \\ F & 8 & C \\ G & 16 & D, E \\ H & 8 & F, G \\ K & 2 & B \\ L & 5 & G, K \\ \hline \end{array} \] 

The total time (in days, in integer) for project completion is \(\underline{\hspace{2cm}}\). 
 

A perfectly flexible and inextensible cable is shown in the figure (not to scale). The external loads at F and G are acting vertically. 

A prismatic fixed-fixed beam, modelled with a total lumped-mass of 10 kg as a single degree of freedom (SDOF) system is shown in the figure. 

A prismatic steel beam is shown in the figure. 

The plastic moment, \( M_p \) calculated for the collapse mechanism using static method and kinematic method is 
 

An equipment has been purchased at an initial cost of ₹160000 and has an estimated salvage value of ₹10000. The equipment has an estimated life of 5 years. The difference between the book values (in ₹, in integer) obtained at the end of the 4\(^\text{th}\) year using straight line method and sum of years digit method of depreciation is \(\underline{\hspace{1cm}}\).
An elevated cylindrical water storage tank is shown in the figure. The tank has inner diameter of 1.5 m. It is supported on a solid steel circular column of diameter 75 mm and total height \( L \) of 4 m. Take, water density = 1000 kg/m\(^3\) and acceleration due to gravity = 10 m/s\(^2\). \includegraphics[width=0.25\linewidth]{image37.png} \[ \text{If elastic modulus (E) of steel is 200 GPa, ignoring self-weight of the tank, for the supporting steel column to remain unbuckled, the maximum depth (h) of the water permissible (in m, round off to one decimal place) is \(\underline{\hspace{1cm}}\).} \]