Dhani Healthcare Interview Questions and Answers

Designing a shaft under bending, torsion and axial loads using Tresca or Von-Mises theory for ductile material.

• Shaft design involves considering the effects of bending, torsion, and axial loads.

• Tresca theory assumes that yielding occurs when the maximum shear stress in a material reaches a critical value.

• Von-Mises theory assumes that yielding occurs when the equivalent stress in a material reaches a critical value.

• Ductile materials are those that can undergo significant plast...read more

Resultant stiffness of two equal parts of a cut spring attached in parallel is 4K.

• When two springs are attached in parallel, the resultant stiffness is the sum of their individual stiffness.

• The stiffness of a spring is directly proportional to its length and inversely proportional to its cross-sectional area.

• Therefore, when a spring of length L and stiffness K is cut into two equal parts, each part will have a length of L/2 and a stiffness of 2K.

• When these two parts are attac...read more

The natural frequency of a simple mass system with the mass of the spring considered.

• Natural frequency is the frequency at which a system oscillates without any external force.

• The formula for natural frequency is sqrt(k/m)

• Where k is the spring constant and m is the mass of the system.

• The mass of the spring is added to the total mass of the system.

• Example: A mass of 2 kg is attached to a spring with a spring constant of 10 N/m. The mass of the spring is 0.5 kg. The natural fre...read more

Different ways to operate a system above its natural frequency

• Adding mass to the system

• Changing the stiffness of the system

• Applying external force to the system

• Using active control techniques

• Using passive control techniques

• Using hybrid control techniques

The first natural frequency of a semi-definite system is zero, which represents rigid body motion.

• The first natural frequency of a system is the frequency at which it oscillates without any external force applied.

• A semi-definite system has one or more degrees of freedom that are constrained, resulting in rigid body motion.

• The first natural frequency of a semi-definite system is always zero, regardless of the number of degrees of freedom.

• Examples of semi-definite systems inclu...read more